ISSN e:2007-4034 / ISSN print: 2007-4034

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     Vol. 11, issue 1 January - June 2005   Creative Commons License

      
 

     Vol. 11, issue 1 January - June 2005  

 
  

IMPROVEMENT OF SHELF LIFE AND QUALITY OF PAPAYA ‘MARADOL’ WITH 1-METHYLCYCLOPROPENE (1-MCP)

MEJORAMIENTO DE VIDA DE ANAQUEL Y CALIDAD DE PAPAYA ‘MARADOL’ CON 1-METILCICLOPROPENO (1-MCP)

Jorge Alberto Osuna-García; J.A. Beltrán; María Hilda Pérez-Barraza

Keywords: Carica papaya L., post-harvest, firmness, color.

10.5154/r.rchsh.2003.12.081

Received: 0000-00-00
Accepted: 0000-00-00
Available online: 2016-07-01
Pages:7-12

Two essays were established to evaluate the effect of rates of 1-MCP on shelf life and quality of ‘Maradol’ papaya. We evaluated three concentrations of 1-MCP (0, 100 and 200 nl·liter-1) for the first essay, the compound was applied in 0.512 m3 hermetical experiment chambers for 12 h at 12 ± 0.5 ºC. Later, fruits were stored for four days at room temperature, four days under refrigeration, and six more days at room temperature. For the second essay, we only used the 200 nl·liter-1 concentration of 1-MCP compared against a control with no application. Application of 1-MCP was done in a 50 m3 commercial chamber for 12 h at 12 ± 0.5 ºC. Fruits were stored under refrigeration for six days and later were transferred to simulated market conditions. We evaluated weight loss, firmness, external and internal color, total soluble solids and diseases. We found that, under both room temperature and refrigeration conditions, 1-MCP at 200 nl·liter-1 increased fruit shelf life and maintained fruit quality because it diminished weight loss, delayed the development of external and internal color, and delayed the evolution of soluble solids; likewise, it reduced disease incidence and maintained fruit firmness for longer time. In the semi-commercial evaluation, 1-MCP at 200 nl·liter-1 demonstrated its potential as an aid in the exporting papaya of Nayarit, México, to Canada, because it increased shelf life without detracting quality.

Two essays were established to evaluate the effect of rates of 1-MCP on shelf life and quality of ‘Maradol’ papaya. We evaluated three concentrations of 1-MCP (0, 100 and 200 nl·liter-1) for the first essay, the compound was applied in 0.512 m3 hermetical experiment chambers for 12 h at 12 ± 0.5 ºC. Later, fruits were stored for four days at room temperature, four days under refrigeration, and six more days at room temperature. For the second essay, we only used the 200 nl·liter-1 concentration of 1-MCP compared against a control with no application. Application of 1-MCP was done in a 50 m3 commercial chamber for 12 h at 12 ± 0.5 ºC. Fruits were stored under refrigeration for six days and later were transferred to simulated market conditions. We evaluated weight loss, firmness, external and internal color, total soluble solids and diseases. We found that, under both room temperature and refrigeration conditions, 1-MCP at 200 nl·liter-1 increased fruit shelf life and maintained fruit quality because it diminished weight loss, delayed the development of external and internal color, and delayed the evolution of soluble solids; likewise, it reduced disease incidence and maintained fruit firmness for longer time. In the semi-commercial evaluation, 1-MCP at 200 nl·liter-1 demonstrated its potential as an aid in the exporting papaya of Nayarit, México, to Canada, because it increased shelf life without detracting quality.

 

DYNAMICS OF TUBERIZED ROOT FORMATION OF CHAYOTE (Sechium edule Sw.) IN ITS FIRST YEAR OF GROWTH

DINÁMICA DE LA FORMACIÓN DE LA RAÍZ TUBERIZADA DEL CHAYOTE (Sechium edule Sw.) EN SU PRIMER AÑO DE CUL

Artemio Cruz-León; M.T.J López-Rueda

Keywords: tuberized root, storage organs, fibrous root, root growth.

10.5154/r.rchsh.2003.12.083

Received: 2003-12-11
Accepted: 2004-06-16
Available online: 2016-07-01
Pages:13-19

Chayote is a perennial plant with annual growth, and, by possessing storage organs, it can sprout and initiate the first growth stages of a new cycle. These natural qualities, added to its consumption, and by making the most of its vegetative parts, turn chayote into a crop well appreciated by growers and indigenous people. Fruits from this plant are also sold in the market. Empirical knowledge of chayote by growers, attributes a great nutritional value to the tuberized root of the plant, which has been barely studied. With the objective to contribute to the knowledge of traits and the formation process of such tuberized root, we established a plantation that was monitored for one year; thus we determined the dynamics of formation of the tuberized root for the same period. Characteristics of “chayotextle”, the popular name of this root, were described. Results contributed to establish a basis to increase knowledge of root formation, characteristics, and the relationships established with photoperiod in the behavior of the plant’s external organs. Our study allowed providing reference points in terms of length, thickness, color, form, texture and distribution in the soil, as well as appearing time, volume increase, and thickened root decomposition period of the species studied. We also noted contributions about the empirical knowledge from growers that take advantage of the tuberized roots of the chayote plant.

Chayote is a perennial plant with annual growth, and, by possessing storage organs, it can sprout and initiate the first growth stages of a new cycle. These natural qualities, added to its consumption, and by making the most of its vegetative parts, turn chayote into a crop well appreciated by growers and indigenous people. Fruits from this plant are also sold in the market. Empirical knowledge of chayote by growers, attributes a great nutritional value to the tuberized root of the plant, which has been barely studied. With the objective to contribute to the knowledge of traits and the formation process of such tuberized root, we established a plantation that was monitored for one year; thus we determined the dynamics of formation of the tuberized root for the same period. Characteristics of “chayotextle”, the popular name of this root, were described. Results contributed to establish a basis to increase knowledge of root formation, characteristics, and the relationships established with photoperiod in the behavior of the plant’s external organs. Our study allowed providing reference points in terms of length, thickness, color, form, texture and distribution in the soil, as well as appearing time, volume increase, and thickened root decomposition period of the species studied. We also noted contributions about the empirical knowledge from growers that take advantage of the tuberized roots of the chayote plant.

 

ALCALOIDES OBTENIDOS DE VARIOS SUBCULTIVOS DE CALLOS DE Erythrina Americana Miller

ALKALOIDS FROM SEVERAL SUBCULTURES OF Erythrina Americana Miller CALLUSES

Ma. del Rosario García-Mateos; Ramón M. Soto-Hernández; R.J.M. Gutiérrez; Ángel Villegas-Monter

Keywords: Leguminosae, cotyledons, seeds, alkaloids, calli erythroidines, liquid chromatography-mass spectrometry.

10.5154/r.rchsh.2003.09.051

Received: 2003-09-03
Accepted: 2004-06-04
Available online: 2016-07-01
Pages:21-26

Isoquinoline alkaloids were detected in calli and seeds from the species Erythrina americana Miller, which were identified using liquid chromatography coupled with mass spectrometry. We studied the effect of subcultures on production of alkaloids from E. americana making seven subcultures of calli. Comparison of the methanolic extract obtained from seeds and cotyledons using the seven callus subcultures from E. americana Miller showed the presence of mainly α and β erythroidines.

Isoquinoline alkaloids were detected in calli and seeds from the species Erythrina americana Miller, which were identified using liquid chromatography coupled with mass spectrometry. We studied the effect of subcultures on production of alkaloids from E. americana making seven subcultures of calli. Comparison of the methanolic extract obtained from seeds and cotyledons using the seven callus subcultures from E. americana Miller showed the presence of mainly α and β erythroidines.

 

EFFECT OF WATER SOAKING ON SEED GERMINATION OF PAPAYA VAR. MARADOL

EFECTO DEL REMOJO EN AGUA SOBRE LA GERMINACIÓN DE SEMILLAS DE PAPAYA Var. MARADOL

M. Salvador-Figueroa; María de Lourdes Adriano-Anaya; C. Becerra-Ortiz

Keywords: Carica papaya L., seedlings, emergence, dormancy.

10.5154/r.rchsh.2003.01.011

Received: 2003-01-30
Accepted: 2004-06-18
Available online: 2016-07-01
Pages:27-30

It was studied the effect of soaking period, in sterile water, of seeds of Carica papaya var. Maradol on seedling emergence. It was found that the beginning of emergency decreased as soaking period increased. When seeds were soaked 96 or 120 g, seedling emergence was observed after 9 and 8 days, respectively [13 days of net time (soaking period + seeding to emergence of first seedling period)]; while, for the 24 h soaking treatment, the first seedlings were observed 17 days after seeding (18 days of net time). We observed that seedling emergence speed increased 12 times from 24 to 120 h of soaking. Likewise, 98 % of emergence was reached 18 days after seeding for the pre-germination treatment of 120 h. We thought that, aside from softening of the seed coats, soaking diluted phenolic compounds that inhibit germination and interrupted embryo dormancy.

It was studied the effect of soaking period, in sterile water, of seeds of Carica papaya var. Maradol on seedling emergence. It was found that the beginning of emergency decreased as soaking period increased. When seeds were soaked 96 or 120 g, seedling emergence was observed after 9 and 8 days, respectively [13 days of net time (soaking period + seeding to emergence of first seedling period)]; while, for the 24 h soaking treatment, the first seedlings were observed 17 days after seeding (18 days of net time). We observed that seedling emergence speed increased 12 times from 24 to 120 h of soaking. Likewise, 98 % of emergence was reached 18 days after seeding for the pre-germination treatment of 120 h. We thought that, aside from softening of the seed coats, soaking diluted phenolic compounds that inhibit germination and interrupted embryo dormancy.

 

EFFECT OF GENOTYPE ON MICROPROPAGATION OF HUSK TOMATO

EFECTO DEL GENOTIPO EN LA MICROPROPAGACIÓN DE TOMATE DE CÁSCARA

María Andrade-Rodríguez; M.C. López-Peralta; Víctor A. González-Hernández; A. García-Velázquez; Aureliano Peña-Lomelí

Keywords: Physalis ixocarpa Brot., tomatillo, shoot induction, elongation, rooting, genotype, chromosomes.

10.5154/r.rchsh.2003.06.040

Received: 2003-06-21
Accepted: 2004-06-21
Available online: 2016-07-01
Pages:31-37

The ability of induction and elongation in vitro, rooting, acclimation, and chromosome stability of seedlings from ten varieties of Physalis ixocarpa Brot. was studied. A genotype effect was found at the four micropropagation stages, shoot induction, proportion of explants with shoots varied from 0 to 70 %, the number of shoots per explant was 0 to 21.3, and the best varieties were ‘Tamazula’, ‘CHF1-Chapingo’ and ‘Rendidora’. During elongation, shoots presented heights from 2.5 to 3.7 cm, 4 to 5 leaves, 104 to 160 mg of fresh weight, and 94.7 to 96.1 % of moisture content; varieties CHF1-Chapingo, Milpero and Arandas had the best response. For rooting, soots produces from 26.6 to 65.6 roots with length from 0.7 to 1.5 cm, were ‘Manzano’ and ‘Puebla’ were the best varieties. The critical acclimation period for the seedlings consisted of the first seven days after transplant, but a 100 % survival was accomplished. All in vitro regenerated plants were 2n=24, indicating chromosome stability during in vitro cultivation.

The ability of induction and elongation in vitro, rooting, acclimation, and chromosome stability of seedlings from ten varieties of Physalis ixocarpa Brot. was studied. A genotype effect was found at the four micropropagation stages, shoot induction, proportion of explants with shoots varied from 0 to 70 %, the number of shoots per explant was 0 to 21.3, and the best varieties were ‘Tamazula’, ‘CHF1-Chapingo’ and ‘Rendidora’. During elongation, shoots presented heights from 2.5 to 3.7 cm, 4 to 5 leaves, 104 to 160 mg of fresh weight, and 94.7 to 96.1 % of moisture content; varieties CHF1-Chapingo, Milpero and Arandas had the best response. For rooting, soots produces from 26.6 to 65.6 roots with length from 0.7 to 1.5 cm, were ‘Manzano’ and ‘Puebla’ were the best varieties. The critical acclimation period for the seedlings consisted of the first seven days after transplant, but a 100 % survival was accomplished. All in vitro regenerated plants were 2n=24, indicating chromosome stability during in vitro cultivation.

 

ACTIVITY OF THE ENZYME POLYPHENOL OXIDASE AND SUSCEPTIBILITY TO DAMAGE FROM LATEX IN ‘HADEN’ AND ‘TOMMY ATKINS’ MANGOES

ACTIVIDAD DE LA ENZIMA POLIFENOL OXIDASA Y SUSCEPTIBILIDAD AL DAÑO POR LATEX EN MANGOS ‘HADEN’

F. Díaz de León-Sánchez; F. Rivera-Cabrera; E. Bosquez-Molina; J. Domínguez-Soberanes; Y. Álvarez-Hoppe; L.J. Pérez-Flores

Keywords: Mangifera indica L., exocarp PPO, latex PPO, post-harvest losses, fruit quality.

10.5154/r.rchsh.2003.10.062

Received: 2003-10-08
Accepted: 2004-06-22
Available online: 2016-07-01
Pages:39-42

Damage from latex (DPL) represents a problem in Mexican mango, causing up to 10 % of annual losses. DPL begins when exuded latex touches the fruit’s skin, producing a superficial darkness that diminishes mango quality and commercial value. Previous studies in mango suggest that terpens favor damage from latex through the activation of polyphenoloxidases (PPO’s). The objective of this study was to determine the correlation between damage from latex and the activity of total PPO’s of the exocarp and latex in ‘Haden’ and ‘Tommy Atkins’ mangoes harvested in April, May, and June in Lázaro Cárdenas, Michoacán, México. Enzyme activity was measured with a spectrophotometer and susceptibility to DPL was evaluated as the percentage of damaged area. Activity of exocarp total PPO’s was similar for ‘Tommy Atkins’ and ‘Haden’ during the first two harvest seasons, and it only increased for ‘Tommy Atkins’ in the last harvest season. Susceptibility to DPL showed contrasting performance between both cultivars. In ‘Haden’ it increased throughout the three seasons while it decreased in ‘Tommy Atkins’. Therefore, total activity of exocarp PPO’s and damage from latex do not explain susceptibility to DPL in Mexican mango. We suggest including the analysis of other components and latex enzymes in future experiments on susceptibility to DPL.

Damage from latex (DPL) represents a problem in Mexican mango, causing up to 10 % of annual losses. DPL begins when exuded latex touches the fruit’s skin, producing a superficial darkness that diminishes mango quality and commercial value. Previous studies in mango suggest that terpens favor damage from latex through the activation of polyphenoloxidases (PPO’s). The objective of this study was to determine the correlation between damage from latex and the activity of total PPO’s of the exocarp and latex in ‘Haden’ and ‘Tommy Atkins’ mangoes harvested in April, May, and June in Lázaro Cárdenas, Michoacán, México. Enzyme activity was measured with a spectrophotometer and susceptibility to DPL was evaluated as the percentage of damaged area. Activity of exocarp total PPO’s was similar for ‘Tommy Atkins’ and ‘Haden’ during the first two harvest seasons, and it only increased for ‘Tommy Atkins’ in the last harvest season. Susceptibility to DPL showed contrasting performance between both cultivars. In ‘Haden’ it increased throughout the three seasons while it decreased in ‘Tommy Atkins’. Therefore, total activity of exocarp PPO’s and damage from latex do not explain susceptibility to DPL in Mexican mango. We suggest including the analysis of other components and latex enzymes in future experiments on susceptibility to DPL.

 

GROWTH AND POST-TRANSPLANTING STRESS OF PINE TREES IN URBAN SALINE SOIL

CRECIMIENTO Y ESTRÉS POST-TRASPLANTE DE ÁRBOLES DE PINO EN SUELO SALINO URBANO

Leopoldo Mohedano-Caballero; Víctor M. Cetina-Alcalá; A. Chacalo-Hilu; A. Trinidad-Santos; F. González-Cossio

Keywords: Pinus greggii Engelm., ball, burlap, stress, salinity, transplant

10.5154/r.rchsh.2003.06.042

Received: 2003-06-24
Accepted: 2004-06-23
Available online: 2016-07-01
Pages:43-50

The urban environment and some arboriculture practices cause a reduction of tree growth (physiological stress), that cannot always be perceived visually. Stress has been studied in several arboreal species using diverse methods that require costly high-precision equipment. In Mexico there is little research on this, despite the great amount of species with arboriculture use potential. This investigation has the purpose of identifying stress in Pinus greggii Engelm., transplanted into urban saline soil. We used 25 seven-year-old trees; some were balled and burlaped (B & B) 90 and 180 days before being transplanted, with and without sulfur in the soil. Control trees were not (B & B) nor transplanted. Techniques used to identify stress in the trees were: leaf photosynthetic efficiency, measured as chlorophyll fluorescence; intensity of green in the foliage; and plant-geoelectric current of the soil-plant system; also tree height and trunk diameter growth. According to results obtained, photosynthetic efficiency and plant-geoelectric current identified a growth decrease (stress) in pines, as a result of B & B and trasplanting. According to B & B period, 180-day treatment recovered their levels for the variables considered before those plants bagged for 90 days. Soil salinity did no affect treatments, because trees were watered regularly, avoiding stress due to moisture deficiency and lixiviating excess salts from the soil.

The urban environment and some arboriculture practices cause a reduction of tree growth (physiological stress), that cannot always be perceived visually. Stress has been studied in several arboreal species using diverse methods that require costly high-precision equipment. In Mexico there is little research on this, despite the great amount of species with arboriculture use potential. This investigation has the purpose of identifying stress in Pinus greggii Engelm., transplanted into urban saline soil. We used 25 seven-year-old trees; some were balled and burlaped (B & B) 90 and 180 days before being transplanted, with and without sulfur in the soil. Control trees were not (B & B) nor transplanted. Techniques used to identify stress in the trees were: leaf photosynthetic efficiency, measured as chlorophyll fluorescence; intensity of green in the foliage; and plant-geoelectric current of the soil-plant system; also tree height and trunk diameter growth. According to results obtained, photosynthetic efficiency and plant-geoelectric current identified a growth decrease (stress) in pines, as a result of B & B and trasplanting. According to B & B period, 180-day treatment recovered their levels for the variables considered before those plants bagged for 90 days. Soil salinity did no affect treatments, because trees were watered regularly, avoiding stress due to moisture deficiency and lixiviating excess salts from the soil.

 

CHILLING INJURY, HARVEST INDEX, AND POST-HARVEST TREATMENTS IN SOURSOP

DAÑOS POR FRÍO EN GUANÁBANA. ÍNDICE DE CORTE Y TRATAMIENTOS POSTCOSECHA

D. Castillo-Ánimas; G. Varela-Hernández; B.R. Pérez-Salvador; C. Pelayo-Zaldívar

Keywords: Anonna muricata L., maturity at harvest, respiratory pattern, refrigerated storage, post-harvest life

10.5154/r.rchsh.2003.08.049

Received: 2003-08-21
Accepted: 2004-06-28
Available online: 2016-07-01
Pages:51-57

To provide practical recommendations to soursop growers on harvest index and storage conditions, it was evaluated the effect of harvest maturity stage and post-harvest treatments in the conservation of this fruit. Harvested soursops at dark and pale green coloration were submitted, after previous selection and randomization, to a wash with chlorinated water at 200 mg×liter-1, to waxing with formulations of “candelilla” wax only or containing growth regulators, and to storage at room and refrigerated temperatures. Dark green fruits showed a respiratory pattern and normal texture changes at 20 °C, but when stored at 20-22 and 24-26 °C, they ripened more slowly than pale green fruits, but at 12-14 and 16-18 °C they suffered cold damage, while pale green fruits showed this type of damage only at 12-14 °C when their texture was firm at the time of storing. Thus we recommend harvesting dark green SOPs to be stored at 20-26 °C, and pale green ones if they are to be stored at 16-18 °C, or, furthermore, at 12-14 °C if they already had acquired a firm-changing texture. “Candelilla” wax formulation 170 delayed maturity, increased the percentage of fruit for commercial purposes, and limited weight loss more consistently than formulation 168. However, it was not observed an effect of formulation 170 containing giberellic acid at 250 mg×liter-1, 2,4 dichloro-phenoxyacetic acid isopropylic ester at 250 mg×liter-1, or a mixture of both each at 250 mg×liter-1 for these variables. Given that the percentage of fruit for commercial purposes was lower than 90 % after only four days at 20-26 °C for dark and pale green fruits, and after eight days at 16-18 °C for pale green ones. Other alternatives for better conservation of fresh soursop are discussed.

To provide practical recommendations to soursop growers on harvest index and storage conditions, it was evaluated the effect of harvest maturity stage and post-harvest treatments in the conservation of this fruit. Harvested soursops at dark and pale green coloration were submitted, after previous selection and randomization, to a wash with chlorinated water at 200 mg×liter-1, to waxing with formulations of “candelilla” wax only or containing growth regulators, and to storage at room and refrigerated temperatures. Dark green fruits showed a respiratory pattern and normal texture changes at 20 °C, but when stored at 20-22 and 24-26 °C, they ripened more slowly than pale green fruits, but at 12-14 and 16-18 °C they suffered cold damage, while pale green fruits showed this type of damage only at 12-14 °C when their texture was firm at the time of storing. Thus we recommend harvesting dark green SOPs to be stored at 20-26 °C, and pale green ones if they are to be stored at 16-18 °C, or, furthermore, at 12-14 °C if they already had acquired a firm-changing texture. “Candelilla” wax formulation 170 delayed maturity, increased the percentage of fruit for commercial purposes, and limited weight loss more consistently than formulation 168. However, it was not observed an effect of formulation 170 containing giberellic acid at 250 mg×liter-1, 2,4 dichloro-phenoxyacetic acid isopropylic ester at 250 mg×liter-1, or a mixture of both each at 250 mg×liter-1 for these variables. Given that the percentage of fruit for commercial purposes was lower than 90 % after only four days at 20-26 °C for dark and pale green fruits, and after eight days at 16-18 °C for pale green ones. Other alternatives for better conservation of fresh soursop are discussed.

 

GROWTH, WATER RELATIONS AND LEAF GAS EXCHANGE OF PLANTS OF ILAMA (Annona diversifolia Saff.) UNDER WATER STRESS CONDITIONS.

CRECIMIENTO, RELACIONES HÍDRICAS E INTERCAMBIO GASEOSO DE PLANTAS JÓVENES DE ILAMA (Annona diversifolia Saff.) EN CONDICIONES DE ESTRÉS HÍDRICO

M. A. Otero-Sánchez; Lucero del Mar Ruiz-Posadas; A.E. Becerril-Román; L. Tijerina-Chávez; E.M. Engleman; Alberto Castillo-Morales

Keywords: Leaf water potential, proline, leaf conductance, transpiration, CO2 assimilation.

10.5154/r.rchsh.2003.04.030

Received: 2003-04-11
Accepted: 2004-07-27
Available online: 2016-07-01
Pages:59-65

They were studied some morphological and physiological characteristics or Annona diversifolia Saff. in relation to soil moisture availability conditions. Soil moisture level affected leaf area and dry matter distribution. Leaf water potential decreased as soil water potential did, with values of -1.26, -1.51, 1.73, 1.76 and 2.36 MPa, for the control, drought 1, drought 2, drought 3 and non-irrigated treatment, respectively. The rate of gas exchange also decreased significantly at the three levels of soil moisture. Proline concentration was negatively correlated to osmotic potential; however, regression analysis did not show any defined tendency. Ten days after the recuperation irrigation, the rate of gas exchange recovered almost entirely for moderate stress treatments.

They were studied some morphological and physiological characteristics or Annona diversifolia Saff. in relation to soil moisture availability conditions. Soil moisture level affected leaf area and dry matter distribution. Leaf water potential decreased as soil water potential did, with values of -1.26, -1.51, 1.73, 1.76 and 2.36 MPa, for the control, drought 1, drought 2, drought 3 and non-irrigated treatment, respectively. The rate of gas exchange also decreased significantly at the three levels of soil moisture. Proline concentration was negatively correlated to osmotic potential; however, regression analysis did not show any defined tendency. Ten days after the recuperation irrigation, the rate of gas exchange recovered almost entirely for moderate stress treatments.

 

CONTROLLED POLLINATION HUSK TOMATO (Physalis ixocarpa Brot.)

POLINIZACIÓN CONTROLADA EN TOMATE DE CÁSCARA (Physalis ixocarpa Brot.)

J.F. Santiaguillo-Hernández; T. Cervantes-Santana; Aureliano Peña-Lomelí; J.D. Molina- Galán; Jaime Sahagún-Castellanos

Keywords: tomatillo, self-incompatibility, flower set, parthenocarpy, plant-to-plant crosses.

10.5154/r.rchsh.2003.10.064

Received: 2003-10-14
Accepted: 2004-07-27
Available online: 2016-07-01
Pages:67-71

Different types of pollination were evaluated in the husk tomato varieties CHF1-Chapingo and Verde Puebla. Treatments consisted of combinations of varieties, covered branches, covered plants and plants under open-pollination (PL). Covering of the two first groups mentioned was done with Agribon, and branches and plants were alone or in pairs of the same or different varieties. In the last group aforementioned (control) plants were without covering. It was used a randomized complete block experimental design with four replications and an experimental plot of on row with three plants. The traits measured by branch or plant were: number of flowers (NFL), number of fruits (NFR) and number of fruits with seed, which was used to calculate the percentage of set flowers (PFLA) and the percentage of fruits with seeds (PFRCS). Results indicated that NFL and NFR from covered branches were statistically lower to those from plants covered in pairs or covered alone; the latter had a similar NFL and lower NFR than plants under PL. The highest PFLA was observed in covered branches (67.9) and PL plants (60.1), and the lowest PFLA was obtained from plants covered alone (45.5). PFRCS from covered branches (5.0), pairs of covered plants (8.5), and alone (4.8) were the same, but inferior to those from plants under PL (29.1). For both NFL and NFR, ‘CHF1-Chapingo’ was superior to ‘Verde Puebla’ under different types of pollination, except for plants under PL; the combination of ‘CHG1-Chapingo’ and ‘Verde Puebla’ in branches was similar to ‘Verde Puebla’, but in plants it was similar to ‘CHF1-Chapingo’. ‘CH1-Chapingo’ and ‘Verde Puebla’ were the same in PFLA and PFRCS under four types of pollination, and the combination o ‘CH1-Chapingo’ and ‘Verde Puebla’ in branches was generally intermediate to both varieties.

Different types of pollination were evaluated in the husk tomato varieties CHF1-Chapingo and Verde Puebla. Treatments consisted of combinations of varieties, covered branches, covered plants and plants under open-pollination (PL). Covering of the two first groups mentioned was done with Agribon, and branches and plants were alone or in pairs of the same or different varieties. In the last group aforementioned (control) plants were without covering. It was used a randomized complete block experimental design with four replications and an experimental plot of on row with three plants. The traits measured by branch or plant were: number of flowers (NFL), number of fruits (NFR) and number of fruits with seed, which was used to calculate the percentage of set flowers (PFLA) and the percentage of fruits with seeds (PFRCS). Results indicated that NFL and NFR from covered branches were statistically lower to those from plants covered in pairs or covered alone; the latter had a similar NFL and lower NFR than plants under PL. The highest PFLA was observed in covered branches (67.9) and PL plants (60.1), and the lowest PFLA was obtained from plants covered alone (45.5). PFRCS from covered branches (5.0), pairs of covered plants (8.5), and alone (4.8) were the same, but inferior to those from plants under PL (29.1). For both NFL and NFR, ‘CHF1-Chapingo’ was superior to ‘Verde Puebla’ under different types of pollination, except for plants under PL; the combination of ‘CHG1-Chapingo’ and ‘Verde Puebla’ in branches was similar to ‘Verde Puebla’, but in plants it was similar to ‘CHF1-Chapingo’. ‘CH1-Chapingo’ and ‘Verde Puebla’ were the same in PFLA and PFRCS under four types of pollination, and the combination o ‘CH1-Chapingo’ and ‘Verde Puebla’ in branches was generally intermediate to both varieties.

 

INTERFERENCE OF WEEDS ON GROWTH AND YIELD OF TRANSPLANTED DRY CHILE PEPPER

INTERFERENCIA DE MALEZAS EN EL CRECIMIENTO Y RENDIMIENTO DE CHILE SECO DE TRANSPLANTE

Keywords: Capsicum annuum, competition, growth curves, dry matter, non-linear regression.

10.5154/r.rchsh.2003.11.071

Received: 2003-11-05
Accepted: 2004-07-28
Available online: 2016-07-01
Pages:73-81

To study the effect of weed interference on growth and yield of dry chile pepper, field experiments were carried out in different sites in 1998 and 1999. The experiment was established under a completely randomized complete block design with two types of weed interference treatments: plots with weeds and plots without weeds at different time intervals. We measured internode length, stem diameter, plant height and water-use efficiency as a response to time intervals of weed interference, while weed-crop ratio was evaluated based on how much did weed dry matter reduced yield of dry chile pepper. Except for the tight relationship observed between curves and internode lengthening data from 1999, internode length, stem diameter and plant height were always higher under conditions with a an increased period without weed interference when compared to weed interference in both years. For both years, internode length, stem diameter and plant height started decreasing after eight or more weeks of weed interference. In both years, an amount of at least 4 t ha-1 of weed dry matter for treatments with increasing periods of weed interference was enough to decrease crop yields up to 67 % in 1999 and 88 % in 1998, when compared to treatments with lower amounts of weed dry matter. Under conditions of increased periods without weed interference, water-use efficiency measured at any sampling time in 1999 was lower than that in 1998 during the growth cycle, due to a 35 % evapotranspiration water loss that occurred in 1999.

To study the effect of weed interference on growth and yield of dry chile pepper, field experiments were carried out in different sites in 1998 and 1999. The experiment was established under a completely randomized complete block design with two types of weed interference treatments: plots with weeds and plots without weeds at different time intervals. We measured internode length, stem diameter, plant height and water-use efficiency as a response to time intervals of weed interference, while weed-crop ratio was evaluated based on how much did weed dry matter reduced yield of dry chile pepper. Except for the tight relationship observed between curves and internode lengthening data from 1999, internode length, stem diameter and plant height were always higher under conditions with a an increased period without weed interference when compared to weed interference in both years. For both years, internode length, stem diameter and plant height started decreasing after eight or more weeks of weed interference. In both years, an amount of at least 4 t ha-1 of weed dry matter for treatments with increasing periods of weed interference was enough to decrease crop yields up to 67 % in 1999 and 88 % in 1998, when compared to treatments with lower amounts of weed dry matter. Under conditions of increased periods without weed interference, water-use efficiency measured at any sampling time in 1999 was lower than that in 1998 during the growth cycle, due to a 35 % evapotranspiration water loss that occurred in 1999.

 

STARFRUIT (Averroha carambola L.) CROP: AN ALTERNATIVE FOR THE DRY TROPIC

EL CULTIVO DEL CARAMBOLO (Averroha carambola L.) : UNA ALTERNATIVA PARA EL TROPICO SECO

María Hilda Pérez-Barraza; Jorge Alberto Osuna-García; Victor Vázquez-Valdivia

Keywords: Bloom period, adaptation, ‘Maha’, ‘Fwang Tung’, new crops.

10.5154/r.rchsh.2004.01.009

Received: 2004-01-12
Accepted: 2004-07-30
Available online: 2016-07-01
Pages:83-87

The objective was to learn the phenological behavior and production of starfruit cultivars Fwant Tung and Maha, under tropical conditions of Santiago Ixcuintla, Nayarit, Mexico. The study was carried out at the Santiago Ixcuintla Experiment Station, Nayarit, of the National Research Institute or Forestry, Agriculture and Animal Husbandry (INIFAP), which has a sub-humid warm climate with summer precipitation and an altitude of 22 m. Starfruit trees of both cultivars obtained from grafting, started producing fruits after two years of established. Both cultivars produce fruits all year, but show important harvest periods: February to March and September to November. In both periods produce about 150 kg of fruits per tree for ‘Fwang Tung’ and 130 kg for ‘Maha’ (six-year-old trees). Cultivar Fwang Tung shows larger fruits of 147.9 g and 7.3-cm diameter, with a higher content of total soluble solids (9.6 °Bx).

The objective was to learn the phenological behavior and production of starfruit cultivars Fwant Tung and Maha, under tropical conditions of Santiago Ixcuintla, Nayarit, Mexico. The study was carried out at the Santiago Ixcuintla Experiment Station, Nayarit, of the National Research Institute or Forestry, Agriculture and Animal Husbandry (INIFAP), which has a sub-humid warm climate with summer precipitation and an altitude of 22 m. Starfruit trees of both cultivars obtained from grafting, started producing fruits after two years of established. Both cultivars produce fruits all year, but show important harvest periods: February to March and September to November. In both periods produce about 150 kg of fruits per tree for ‘Fwang Tung’ and 130 kg for ‘Maha’ (six-year-old trees). Cultivar Fwang Tung shows larger fruits of 147.9 g and 7.3-cm diameter, with a higher content of total soluble solids (9.6 °Bx).

 

VARIATION IN FLAVONOID CONTENT OF GUAVA LEAVES UNDER STRESS CONDITIONS

VARIACIÓN DEL CONTENIDO DE FLAVONOIDES EN HOJAS DE GUAYABA EN CONDICIONES DE ESTRÉS

D. Vargas-Álvarez; Marco Soto-Hernández; Víctor A. González-Hernández; E.M. Engleman; A. Martinez-Garza

Keywords: Psidium guajava L., flavonoids, quercetin, defoliation, drought, pruning.

10.5154/r.rchsh.2004.02.014

Received: 2004-02-12
Accepted: 2004-09-03
Available online: 2016-07-01
Pages:89-92

In this research, it was used high resolution liquid chromatography to evaluate the content of several flavonoids in guava leaves from trees under defoliation, drought, and pruning. Tree defoliation caused increases from 59 to 128 mg·kg-1 in miricetin, from 945 to 128 mg·kg-1, of quercetin, and from 44 to 57 mg·kg-1 of kaempferol. Drought increased luteolin from 33 to 89 mg·kg-1. Pruning increased miricetin from 54 to 64 mg·kg-1 and quercetin from 850 to 1042 mg·kg-1. Guava trees alter their composition of miricetin, quercetin, kaempferol and luteolin from stress caused by defoliation, drought, and pruning.

In this research, it was used high resolution liquid chromatography to evaluate the content of several flavonoids in guava leaves from trees under defoliation, drought, and pruning. Tree defoliation caused increases from 59 to 128 mg·kg-1 in miricetin, from 945 to 128 mg·kg-1, of quercetin, and from 44 to 57 mg·kg-1 of kaempferol. Drought increased luteolin from 33 to 89 mg·kg-1. Pruning increased miricetin from 54 to 64 mg·kg-1 and quercetin from 850 to 1042 mg·kg-1. Guava trees alter their composition of miricetin, quercetin, kaempferol and luteolin from stress caused by defoliation, drought, and pruning.

 

EFFECT OF PRODUCTS CONTAINING GROWTH REGULATORS ON FLOWERING AND FRUIT SET IN ‘HABANERO’ HOT PEPPER

EFECTO DE PRODUCTOS CON REGULADORES DE CRECIMIENTO SOBRE LA FLORACIÓN Y AMARRE DE FRUTO EN CHILE ‘HABANERO’

E. Ramírez-Luna; C. de la C. Castillo-Aguilar; E. Aceves-Navarro; E. Carrillo-Avila

Keywords: Capsicum chinense Jacq., yield, fruit size.

10.5154/r.rchsh.2003.12.080

Received: 2003-12-09
Accepted: 2004-08-05
Available online: 2016-07-01
Pages:93-98

One of the main problems in the production of ‘Habanero’ hot pepper in the State of Campeche, Mexico, is an important loss in flowers and fruits from the plant. For this reason, the present study had the following objective: to evaluate the effect of different commercial growth regulators on flowering and fruit setting. The evaluation was carried out in the field and the greenhouse in the location of Chiná, Campeche, Mexico, at 18º 41’ North latitude N and 90º 59’ West longitude, by seeding the variety Habanero. Treatments consisted in the application of the following plant regulator products during the reproductive period: Maxigrow, Biofol, Bioforte, Biocrop, Biozyme, and a control treatment consisting in no application of these products. The variables studied were number of flowers and fruits per plant; fruit length and diameter, and fruit yield. Plants of ‘Habanero’ hot pepper showed a positive differential effect to the application of growth regulators, resulting in higher setting of flowers and fruits; and higher yield as well. Cultivation in the greenhouse induced plants to have numerous but small fruits; this was the opposite to what we observed in the field, where we observed smaller plants, with large and well developed fruits, consequently resulting in higher yield.

One of the main problems in the production of ‘Habanero’ hot pepper in the State of Campeche, Mexico, is an important loss in flowers and fruits from the plant. For this reason, the present study had the following objective: to evaluate the effect of different commercial growth regulators on flowering and fruit setting. The evaluation was carried out in the field and the greenhouse in the location of Chiná, Campeche, Mexico, at 18º 41’ North latitude N and 90º 59’ West longitude, by seeding the variety Habanero. Treatments consisted in the application of the following plant regulator products during the reproductive period: Maxigrow, Biofol, Bioforte, Biocrop, Biozyme, and a control treatment consisting in no application of these products. The variables studied were number of flowers and fruits per plant; fruit length and diameter, and fruit yield. Plants of ‘Habanero’ hot pepper showed a positive differential effect to the application of growth regulators, resulting in higher setting of flowers and fruits; and higher yield as well. Cultivation in the greenhouse induced plants to have numerous but small fruits; this was the opposite to what we observed in the field, where we observed smaller plants, with large and well developed fruits, consequently resulting in higher yield.

 

IMPACT OF PHYTOSANITARY BARRIERS IN AVOCADO TRADE BETWEEN MEXICO AND THE UNITED STATES OF AMERICA

IMPACTO DE LAS BARRERAS FITOSANITARIAS EN EL COMERCIO DE AGUACATE ENTRE MÉXICO Y LOS ESTADOS UNIDOS DE NORTEAMÉRICA

Juan Antonio Leos-Rodríguez; M.T. Kido-Cruz; Ramón Valdivia-Alcalá

Keywords: Persea americana Mill., technical barriers, supply and demand, price elasticities, partial equilibrium models, welfare, NAFTA.

10.5154/r.rchsh.2003.11.074

Received: 2003-11-12
Accepted: 2004-08-05
Available online: 2016-07-01
Pages:99-103

Given the current limitations in the export of avocado to the United States (U.S.), derived from the dispute on the presence of seed pests, the avocado trunk and branch weevil and fruit flies, all of quarantine importance, in Mexican avocado orchards; the main objective of this research was to quantify the impacts, on the welfare of both Mexico and the US, associated to the application of different degrees of technical and phytosanitary barriers in the trade of avocado between these two countries. We estimated supply, demand, and import functions for avocado to the U.S. in order to obtain price elasticities of each one of these functions. Based on these results we estimated a partial equilibrium model to analyze the impacts of a higher open avocado trade between Mexico and the U.S. on welfare, commercial fluxes, and prices. Results showed that a total reduction of barriers and tariffs would increase the welfare for both the U.S. and Mexico.

Given the current limitations in the export of avocado to the United States (U.S.), derived from the dispute on the presence of seed pests, the avocado trunk and branch weevil and fruit flies, all of quarantine importance, in Mexican avocado orchards; the main objective of this research was to quantify the impacts, on the welfare of both Mexico and the US, associated to the application of different degrees of technical and phytosanitary barriers in the trade of avocado between these two countries. We estimated supply, demand, and import functions for avocado to the U.S. in order to obtain price elasticities of each one of these functions. Based on these results we estimated a partial equilibrium model to analyze the impacts of a higher open avocado trade between Mexico and the U.S. on welfare, commercial fluxes, and prices. Results showed that a total reduction of barriers and tariffs would increase the welfare for both the U.S. and Mexico.

 

MICROorganism ANTAGONISM AGAINST ICE NUCLEI ACTIVATOR BACTERIA: Pantoea agglomerans and Pseudomonas syringae Van Hall.

ANTAGONISMO MICROBIANO CONTRA BACTERIAS ACTIVADORAS DE NÚCLEOS DE HIELO: Pantoea agglomerans y Pseudomonas syringae Van Hall.

G. López-Granados; S.P. Fernández-Pavía; R. Cárdenas-Navarro; Juan Manuel Sánchez-Yáñez

Keywords: freezing, frost, citrus, phyloplane, epiphytic.

10.5154/r.rchsh.2003.01.007

Received: 2003-01-14
Accepted: 2004-08-16
Available online: 2016-07-01
Pages:105-111

Freezing of leaves in the field depends on physical, chemical, and biological factors. One of the biological factors considered are ice nuclei activator bacteria (BANH), which are epiphytic to the leaf plane (phyloplane). These BANH respond to environmental changes such as high moisture and low temperature to “super cool down” internally and form ice crystals externally to avoid that such physical phenomenon annihilates them. As a consequence plant tissue freezes and the leaf dies. Chemical and biological control used to reduce the density of phyloplane BANH and ice crystals has generated inconsistent results. Information is necessary on native microorganisms with antagonism to BANH in crops of high economic value. In this research we isolated epiphytic microorganisms from citric plants which are antagonist to BANH. We determined the inhibitory effect of these organisms on the growth of BANH ecotypes on nutritive agar. We evaluated the effect of these antagonist microorganisms on the frequency of ice nucleation of BANH in leaves of sweet orange, sour orange, mandarin, and lemon. Results show the existence of epiphytic microorganisms in citrus plants that are antagonists to BANH. The application of these microorganisms to citric leaves reduced damage from freezing. Antagonist microorganisms to BANH were identified as those from the Enterobacteraceae genus and genii of Gram positive bacteriagenera: Escherichia coli, Klebsiella sp., Bacillus sp., and Micrococcus luteus. A yeast was identified as well. It was concluded that these epiphytic antagonist microorganisms may provide an alternative to reduce the effect of BANH on citric plants.

Freezing of leaves in the field depends on physical, chemical, and biological factors. One of the biological factors considered are ice nuclei activator bacteria (BANH), which are epiphytic to the leaf plane (phyloplane). These BANH respond to environmental changes such as high moisture and low temperature to “super cool down” internally and form ice crystals externally to avoid that such physical phenomenon annihilates them. As a consequence plant tissue freezes and the leaf dies. Chemical and biological control used to reduce the density of phyloplane BANH and ice crystals has generated inconsistent results. Information is necessary on native microorganisms with antagonism to BANH in crops of high economic value. In this research we isolated epiphytic microorganisms from citric plants which are antagonist to BANH. We determined the inhibitory effect of these organisms on the growth of BANH ecotypes on nutritive agar. We evaluated the effect of these antagonist microorganisms on the frequency of ice nucleation of BANH in leaves of sweet orange, sour orange, mandarin, and lemon. Results show the existence of epiphytic microorganisms in citrus plants that are antagonists to BANH. The application of these microorganisms to citric leaves reduced damage from freezing. Antagonist microorganisms to BANH were identified as those from the Enterobacteraceae genus and genii of Gram positive bacteriagenera: Escherichia coli, Klebsiella sp., Bacillus sp., and Micrococcus luteus. A yeast was identified as well. It was concluded that these epiphytic antagonist microorganisms may provide an alternative to reduce the effect of BANH on citric plants.

 

ORCHARD MANAGEMENT AND SANITARY PRUNING ON THE INCIDENCE OF MANGO MALFORMATION

MANEJO DE HUERTO Y PODAS SANITARIAS EN LA INCIDENCIA DE LA ESCOBA DE BRUJA DEL MANGO

M.E. López-Estrada; D.H. Noriega-Cantú; G. Otero-Colina; G. Gutiérrez-Reyes

Keywords: Fusarium subglutinans, Mangifera indica, enfermedad, manejo integrado.

10.5154/r.rchsh.2003.08.047

Received: 0000-00-00
Accepted: 0000-00-00
Available online: 2016-07-01
Pages:113-120

Se evaluó el efecto de diferentes manejos de huertos y tipos de podas en la proporción de yemas deformes en mango cv. Haden durante 1999 a 2001. Se establecieron tres tecnologías de manejo: manejo integrado (IM), manejo de altos insumos (HM) y tecnología tradicional (TT); los tipos de poda aplicados en cada tecnología fueron: poda después de la cosecha y durante la floración, poda sólo de las yemas deformes a 30 cm de ellas, poda después de la cosecha, a 30, 80 y 120 cm de las yemas deformes, más el testigo, sin poda. IM mostró una proporción significativamente más baja de yemas deformes y de área bajo la curva del progreso de la enfermedad, comparado con TT al final del periodo 2000-2001, lo que sugiere efecto a largo plazo. Aunque se encontraron diferencias significativas entre los tipos de poda, no se encontró interacción entre el manejo y dichos tipos de poda. Los tipos de poda fueron estadísticamente diferentes respecto al testigo, lo que sugiere que la proporción de yemas deformes es reducida por la poda de las ramas afectadas. La poda después de la cosecha a 80 y 30 cm de la zona afectada mantuvo los valores más bajos de deformación de yemas en ambos periodos, lo que lleva a recomendar este tipo de poda como parte de IM.

Se evaluó el efecto de diferentes manejos de huertos y tipos de podas en la proporción de yemas deformes en mango cv. Haden durante 1999 a 2001. Se establecieron tres tecnologías de manejo: manejo integrado (IM), manejo de altos insumos (HM) y tecnología tradicional (TT); los tipos de poda aplicados en cada tecnología fueron: poda después de la cosecha y durante la floración, poda sólo de las yemas deformes a 30 cm de ellas, poda después de la cosecha, a 30, 80 y 120 cm de las yemas deformes, más el testigo, sin poda. IM mostró una proporción significativamente más baja de yemas deformes y de área bajo la curva del progreso de la enfermedad, comparado con TT al final del periodo 2000-2001, lo que sugiere efecto a largo plazo. Aunque se encontraron diferencias significativas entre los tipos de poda, no se encontró interacción entre el manejo y dichos tipos de poda. Los tipos de poda fueron estadísticamente diferentes respecto al testigo, lo que sugiere que la proporción de yemas deformes es reducida por la poda de las ramas afectadas. La poda después de la cosecha a 80 y 30 cm de la zona afectada mantuvo los valores más bajos de deformación de yemas en ambos periodos, lo que lleva a recomendar este tipo de poda como parte de IM.

 

GENETIC EFFECTS AND INTERACTIONS AMONG MAIZE FAMILIES AND ISOLATES OF HUITLACOCHE (Ustilago maydis D. C. Corda)

EFECTOS GENÉTICOS E INTERACCIONES ENTRE FAMILIAS DE MAÍZ Y AISLADOS DEL HUITLACOCHE (Ustilago maydis D. C. Corda)

Lauro Martínez-Martínez; Abel Muñoz-Orozco; J.A. Mejía-Contreras; José D. Molina-Galán; Emma Zavaleta-Mejía; Sergio Sandoval-Islas; Clemente Villanueva-Verduzco

Keywords: corn smut, pathosystem, variance components, fungus.

10.5154/r.rchsh.2003.09.055

Received: 2003-09-17
Accepted: 2004-08-23
Available online: 2016-07-01
Pages:121-128

The pathosystem maize-huitlacoche has coevolved since prehispanic times until sustaining itself, currently, in a coequilibrated coexistence. Due to the economical importance acquired by this fungus and to the development of techniques for its artificial induction, it is necessary to learn the relationships among the variation of the pathogen, the host, and the environmental conditions under which both prosper. The objective of this research was to estimate, in two agricultural cycles, the variance components of the performance of 12 maternal half-sib maize families combined with 10 isolates of Ustilago maydis D. C. Corda in terms of percentages of severity and incidence and yield of fungus per plant. We observed significant and highly significant differences among families and among isolates. The estimation of variance components of mean square expected values indicated that this significance was attributed mostly to interaction components than to main effects. As a consequence of the high genotype-environment interaction, families and isolates had different performances from one environment to another, this makes it difficult to recommend a specific family-isolate; it would be more appropriate to use a mixture of isolates on a synthetic made from susceptible genotypes.

The pathosystem maize-huitlacoche has coevolved since prehispanic times until sustaining itself, currently, in a coequilibrated coexistence. Due to the economical importance acquired by this fungus and to the development of techniques for its artificial induction, it is necessary to learn the relationships among the variation of the pathogen, the host, and the environmental conditions under which both prosper. The objective of this research was to estimate, in two agricultural cycles, the variance components of the performance of 12 maternal half-sib maize families combined with 10 isolates of Ustilago maydis D. C. Corda in terms of percentages of severity and incidence and yield of fungus per plant. We observed significant and highly significant differences among families and among isolates. The estimation of variance components of mean square expected values indicated that this significance was attributed mostly to interaction components than to main effects. As a consequence of the high genotype-environment interaction, families and isolates had different performances from one environment to another, this makes it difficult to recommend a specific family-isolate; it would be more appropriate to use a mixture of isolates on a synthetic made from susceptible genotypes.

 

THE EFFECT OF INSECTICIDES ON PEROXIDASE ACTIVITY IN HOT PEPPER PLANTS (Capsicum annum L.)

EFECTO DE INSECTICIDAS EN LA ACTIVIDAD DE LA PEROXIDASA EN PLANTAS DE CHILE PICANTE  (Capsicum annum L.)

José Luis García-Hernández; H. Nolasco; E. Troyo-Diéguez; B. Murillo-Amador; Arnoldo Flores-Hernández; Ignacio Orona-Castillo; Ricardo David Valdez-Cepeda

Keywords: enzyme activity, organophosphoric, oxidative stress.

10.5154/r.rchsh.2003.03.021

Received: 2003-03-17
Accepted: 2004-08-31
Available online: 2016-07-01
Pages:129-133

We evaluated the effect of four organophosphoric insecticides on the physiology of hot pepper. Three commercial products (Gusation 35PH®, Paration CE720®, and Tamaron 600 LM®) and an active ingredient with no mixtures (metamidofos) were used. Four rates were utilized for each product: the average rate recommended in the product’s label (1.0R), but also 0.5 (0.5R), 1.5 (1.5R), and twice the recommended rate (2.0R). Effects were evaluated through peroxidase activity, which is an enzyme frequently used as a biological marker for oxidative stress. Samples analyzed were taken from photosynthetically active leaves. Results show that the highest insecticide rates caused alterations in the expression of the aforementioned enzyme. Differences were found among insecticide, but all of them increased enzyme activity when applied at rates higher than those recommended, which were used as controls, in the labels of the commercial products studied.

We evaluated the effect of four organophosphoric insecticides on the physiology of hot pepper. Three commercial products (Gusation 35PH®, Paration CE720®, and Tamaron 600 LM®) and an active ingredient with no mixtures (metamidofos) were used. Four rates were utilized for each product: the average rate recommended in the product’s label (1.0R), but also 0.5 (0.5R), 1.5 (1.5R), and twice the recommended rate (2.0R). Effects were evaluated through peroxidase activity, which is an enzyme frequently used as a biological marker for oxidative stress. Samples analyzed were taken from photosynthetically active leaves. Results show that the highest insecticide rates caused alterations in the expression of the aforementioned enzyme. Differences were found among insecticide, but all of them increased enzyme activity when applied at rates higher than those recommended, which were used as controls, in the labels of the commercial products studied.

 

BEHAVIOR OF BIOMASS ACCUMULATION AND DISTRIBUTION IN POTATO GENOTYPES ESTABLISHED UNDER RAINFED CONDITIONS

COMPORTAMIENTO DE LA ACUMULACIÓN Y DISTRIBUCIÓN DE BIOMASA EN GENOTIPOS DE PAPA ESTABLECIDOS EN CONDICIONES DE SECANO

Rafael Mora-Aguilar; J. Ortíz-Cereceres; A. Rivera-Peña; M.C. Mendoza-Castillo; Ma. Teresa Colinas-León; Héctor Lozoya-Saldaña; Juan Enrique Rodríguez-Pérez

Keywords: ontogeny, growth models, tuber, yield, phenology.

10.5154/r.rchsh.2003.12.079

Received: 2003-12-02
Accepted: 2004-08-24
Available online: 2016-07-01
Pages:135-142

The study was carried out during the rainfed period of 1996 in Metepec, Mexico, to determine the behavior of biomass accumulation and distribution in the different organs and whole plant of five potato genotypes; these genotypes were established in rows separated at 90 cm with one-stem plants every 30 cm within rows. After emergence, at 7±1 day intervals, five plants under full competition were harvested and dissected for both aerial (leaves, main stem and branch stems) and underground (roots, stolons, tubers and underground main stem section) parts. Later plants were dried in a forced-air stove at 75 °C for 72 h until they reached a constant weight. The behavior of biomass accumulation and distribution towards the different plant organs was associated, in most cases, with the growth habit of the genotypes: determined in ‘Alpha’, ‘Norteña,’ and ‘C-771A11’ or undetermined in ‘Puebla’ and ‘C-676014.’ Accumulation curves were similar among genotypes and their general tendency was adjusted to logistic and polynomial models. From 45 to 50 days after emergence, biomass accumulation for the underground part and the whole plant was almost parallel. Tuber stage duration affected tuber biomass accumulation in such way that intermediate genotypes, such as ‘Norteña’ and ‘C-676014,’ were more efficient (272 and 294 g·plant-1) than early or late ones. Among aerial organs, leaves accumulated more biomass (40-53 and 79-81 g·plant-1), independently from genotype growth habit.

The study was carried out during the rainfed period of 1996 in Metepec, Mexico, to determine the behavior of biomass accumulation and distribution in the different organs and whole plant of five potato genotypes; these genotypes were established in rows separated at 90 cm with one-stem plants every 30 cm within rows. After emergence, at 7±1 day intervals, five plants under full competition were harvested and dissected for both aerial (leaves, main stem and branch stems) and underground (roots, stolons, tubers and underground main stem section) parts. Later plants were dried in a forced-air stove at 75 °C for 72 h until they reached a constant weight. The behavior of biomass accumulation and distribution towards the different plant organs was associated, in most cases, with the growth habit of the genotypes: determined in ‘Alpha’, ‘Norteña,’ and ‘C-771A11’ or undetermined in ‘Puebla’ and ‘C-676014.’ Accumulation curves were similar among genotypes and their general tendency was adjusted to logistic and polynomial models. From 45 to 50 days after emergence, biomass accumulation for the underground part and the whole plant was almost parallel. Tuber stage duration affected tuber biomass accumulation in such way that intermediate genotypes, such as ‘Norteña’ and ‘C-676014,’ were more efficient (272 and 294 g·plant-1) than early or late ones. Among aerial organs, leaves accumulated more biomass (40-53 and 79-81 g·plant-1), independently from genotype growth habit.

 

COLDSTORAGE AND MODIFIED ATMOSPHERES IN MINIMALLY PROCESSED AVOCADO

FRIGOCONSERVACIÓN Y ATMÓSFERAS MODIFICADAS EN FRUTOS DE AGUACATE MÍNIMAMENTE PROCESADO

Ma. Teresa Martínez-Damián; José Alberto Zarazúa-Escobar; Ma. Teresa Colinas-León; Alejandro F. Barrientos-Priego; J.J. Aguilar-Melchor

Keywords: Persea americana Mill., antioxidants, fresh-cut, plastic film.

10.5154/r.rchsh.2002.11.073

Received: 2002-11-12
Accepted: 2004-09-10
Available online: 2016-07-01
Pages:143-148

This study had as an objective to evaluate the effect of two modified atmospheres, one generated by low linear density polyethylene and the other with the use of Vacum 300, at two storage temperatures, 5 and 20 °C, and two antioxidants (b-tocopherol, L-ascorbic acid, and butyl hydroxytoluene) in the prolongation of shelf life of minimally processed avocado. We evaluated physiological weight loss, color, firmness, chilling injury, enzymatic browning, phenolic compounds, polyphenoloxidase activity, disease incidence and severity, and sensorial evaluation. The best treatment was the vacuum film, Vacum 300, with antioxidants (b-tocopherol, L-ascorbic acid, and butyl hydroxytoluene) stored at 5 °C, which had the ability to maintain acceptable aroma and appearance of avocado slices. This treatment also reduced physiological weight loss considerably, diminished disorders caused by chilling, and preserved the product in perfect conditions (free from fungi) for 13 days.

This study had as an objective to evaluate the effect of two modified atmospheres, one generated by low linear density polyethylene and the other with the use of Vacum 300, at two storage temperatures, 5 and 20 °C, and two antioxidants (b-tocopherol, L-ascorbic acid, and butyl hydroxytoluene) in the prolongation of shelf life of minimally processed avocado. We evaluated physiological weight loss, color, firmness, chilling injury, enzymatic browning, phenolic compounds, polyphenoloxidase activity, disease incidence and severity, and sensorial evaluation. The best treatment was the vacuum film, Vacum 300, with antioxidants (b-tocopherol, L-ascorbic acid, and butyl hydroxytoluene) stored at 5 °C, which had the ability to maintain acceptable aroma and appearance of avocado slices. This treatment also reduced physiological weight loss considerably, diminished disorders caused by chilling, and preserved the product in perfect conditions (free from fungi) for 13 days.

 

CALCIUM NITRATE FOLIAR SPRAYS IN THE RIPENING AND CHILLING INJURY OF ‘FUERTE’ AVOCADO

APLICACIONES FOLIARES DE NITRATO DE CALCIO EN LA MADURACIÓN Y DAÑOS POR FRÍO EN AGUACATE ‘FUERTE’

L. Saucedo-Hernández; Ma. Teresa Martínez-Damián; Ma. Teresa Colinas-León; Alejandro F. Barrientos-Priego; J.J. Aguilar-Melchor

Keywords: Persea americana Mill., Ca(NO3)2, post-harvest, refrigeration, quality.

10.5154/r.rchsh.2002.11.074

Received: 0000-00-00
Accepted: 0000-00-00
Available online: 2016-07-01
Pages:149-157

In order to study the effect of calcium on post-harvest of avocado fruits, cv. Fuerte trees were sprayed with Ca(NO3)2 at 0, 0.3 y 0.5 %. Six pre-harvest applications were performed from 4 May 2001, harvest was carried out on January of 2002, once fruits were harvested, they were stored at room temperature and at 5 °C for five weeks, making evaluations at 0, 3 and 5 weeks. The results obtained indicated an increase in skin and pulp calcium content of avocado fruits treated with calcium nitrate. Pre-harvest applications of calcium nitrate at 0.3 and 0.5 % improved fruit firmness and reduced fruit weight loss when compared to the control; likewise there was a decrease in CO2 , ethylene and cold damage.

In order to study the effect of calcium on post-harvest of avocado fruits, cv. Fuerte trees were sprayed with Ca(NO3)2 at 0, 0.3 y 0.5 %. Six pre-harvest applications were performed from 4 May 2001, harvest was carried out on January of 2002, once fruits were harvested, they were stored at room temperature and at 5 °C for five weeks, making evaluations at 0, 3 and 5 weeks. The results obtained indicated an increase in skin and pulp calcium content of avocado fruits treated with calcium nitrate. Pre-harvest applications of calcium nitrate at 0.3 and 0.5 % improved fruit firmness and reduced fruit weight loss when compared to the control; likewise there was a decrease in CO2 , ethylene and cold damage.

 

THERMAL TREATMENT AND LOW DENSITY POLYETHYLENE PACKAGING ON PHYSIOLOGICAL AND HEMICAL CHANGES OF ‘WONDER’ SWEET PEPPER (Capsicum annumm L.)

TRATAMIENTO TÉRMICO Y ENVASADO EN POLIETILENO DE BAJA DENSIDAD, EN LOS CAMBIOS FISIOLÓGICOS Y QUÍMICOS EN CHILE PIMIENTO (Capsicum annumm L.) ‘WONDER’

G.A. González-Aguilar; J. Fortiz-Hernández; R. Cruz-Valenzuela; L. Gayosso-García

Keywords: postharvest quality, ethylene, respiration, ethanol, acetaldehyde.

10.5154/r.rchsh.2003.02.015

Received: 0000-00-00
Accepted: 0000-00-00
Available online: 2016-07-01
Pages:159-165

The objective of the present study was to evaluate immersion in hot water (TIAC; 53 °C for 4 min), by itself or in combination with packaging in low density polyethylene (PEBD), to maintain the post-harvest quality of sweet pepper stored at 10 and 20 °C. Packaging alone maintained fruit quality at low temperature. However, there was an additive effect from combining packaging with TIAC, resulting in a reduction of respiration rate, chlorophyll loss, production of ethanol, acetaldehyde, ethylene, and ACC (1-aminocyclopropane-1-carboxylic acid), and the activity of ACC oxidase. These fruits maintained a better general appearance, a lower deterioration index, and a longer shelf life than the control fruits treated with either the thermal treatment or packaging. The effectiveness of these treatments on maintaining quality seems to be related with the suppression of ethylene synthesis and a possible inhibition of its action.

The objective of the present study was to evaluate immersion in hot water (TIAC; 53 °C for 4 min), by itself or in combination with packaging in low density polyethylene (PEBD), to maintain the post-harvest quality of sweet pepper stored at 10 and 20 °C. Packaging alone maintained fruit quality at low temperature. However, there was an additive effect from combining packaging with TIAC, resulting in a reduction of respiration rate, chlorophyll loss, production of ethanol, acetaldehyde, ethylene, and ACC (1-aminocyclopropane-1-carboxylic acid), and the activity of ACC oxidase. These fruits maintained a better general appearance, a lower deterioration index, and a longer shelf life than the control fruits treated with either the thermal treatment or packaging. The effectiveness of these treatments on maintaining quality seems to be related with the suppression of ethylene synthesis and a possible inhibition of its action.

 

DEHYDRATION METHODS ON COMMERCIAL QUALITY OF ROSE

MÉTODOS DE DESHIDRATACIÓN EN LA CALIDAD COMERCIAL DE LA FLOR DE ROSA

P. Martínez-Aispuro; María Antonieta Goytia-Jiménez; Alejandro F. Barrientos-Priego; Armando Espinosa-Flores

Keywords: Rosa hibrida, dried flower, desiccants, rice flour, silica gel.

10.5154/r.rchsh.2003.10.067

Received: 0000-00-00
Accepted: 0000-00-00
Available online: 2016-07-01
Pages:167-173

One alternative to preserve the aesthetic appearance of the rose flower is to preserve it with drying methods that allow the flower to maintain its fresh flower characteristics. In this study we evaluated the response to dehydration in three Rosa hibrida cultivars: ‘Vega,’ ‘Ravel,’ and ‘Papillon’ with red, pink and yellow flowers, respectively. We worked with two mixtures of desiccants (corn flour-detergent and corn flour-borax) in 1:1 and 2:1 (w:w) proportions for each mixture. In addition, two pure desiccants were evaluated (rice flour and silica gel). Three drying periods were tested: 7, 14 and 20 days for the mixtures and rice flour; but only 2, 3 and 5 days for silica gel. The variables evaluated were: flexibility, firmness, form, color, flower texture, petal abscission, and moisture loss. For both desiccant mixtures and pure desiccants, cultivars Ravel and Papillon had the highest values for most of the variables evaluated. Fourteen days for both mixtures and rice flour and three days with silica gel were the best drying periods for cultivars Ravel and Papillon; cultivar Vega needed 20 days for mixtures and rice flour and five days for silica gel. Desiccants showing the best preservation for quality characteristics in dehydrated roses were: silica gel, desiccant mixtures at a 1:1 proportion, and rice flour, respectively. Drying period and cultivar were critical in obtaining dried roses of good quality.

One alternative to preserve the aesthetic appearance of the rose flower is to preserve it with drying methods that allow the flower to maintain its fresh flower characteristics. In this study we evaluated the response to dehydration in three Rosa hibrida cultivars: ‘Vega,’ ‘Ravel,’ and ‘Papillon’ with red, pink and yellow flowers, respectively. We worked with two mixtures of desiccants (corn flour-detergent and corn flour-borax) in 1:1 and 2:1 (w:w) proportions for each mixture. In addition, two pure desiccants were evaluated (rice flour and silica gel). Three drying periods were tested: 7, 14 and 20 days for the mixtures and rice flour; but only 2, 3 and 5 days for silica gel. The variables evaluated were: flexibility, firmness, form, color, flower texture, petal abscission, and moisture loss. For both desiccant mixtures and pure desiccants, cultivars Ravel and Papillon had the highest values for most of the variables evaluated. Fourteen days for both mixtures and rice flour and three days with silica gel were the best drying periods for cultivars Ravel and Papillon; cultivar Vega needed 20 days for mixtures and rice flour and five days for silica gel. Desiccants showing the best preservation for quality characteristics in dehydrated roses were: silica gel, desiccant mixtures at a 1:1 proportion, and rice flour, respectively. Drying period and cultivar were critical in obtaining dried roses of good quality.

 

INOCULATION OF ARBUSCULAR MYCORRHIZAL FUNGI AND DIFFERENT SOIL: EARTHWORM HUMUS RATIOS ON COFFEE GROWTH (Coffea Arabica L.) CV. CATUAÍ AT THE NURSERY STAGE

INOCULACIÓN DE HONGOS MICORRÍZICOS ARBUSCULARES Y DIFERENTES RELACIONES SUELO: HUMUS DE LOMBRIZ SOBRE EL CRECIMIENTO DEL CAFETO (Coffea Arabica L.) cv. Catuaí BAJO LA ETAPA DE VIVERO

F. Fernández-Martín; Ramón Rivera-Espinosa; A. Hernández-Jiménez; R.A. Herrera-Peraza; K. Fernández-Suárez

Keywords: endophyte mycorrhizal mass, Glomus clarum, Glomus fasciculatum, Glomus spurcum, acrisol soil, cambisol soil.

10.5154/r.rchsh.2003.04.031

Received: 2003-04-11
Accepted: 2004-09-14
Available online: 2016-07-01
Pages:175-184

The objective of this study was to evaluate the effect of inoculating arbuscular mycorrhizal fungi (HMA) and soil:earthworm humus ratio on coffee postures in acrisol, dystric cambric and eutric cambisol soils. Three experiments were carried out under nursery conditions under a completely randomized factorial design, evaluating morphological, fungal, and nutritional variables. Results demonstrated that inoculation with HMA was effective, accomplishing increases in leaf area between 6 and 140 % compared to non-inoculated plants. Mycorrhizal efficiency of inoculated lines was defined by soil fertility and soil:earthworm humus ratio. Endophyte mycorrhizal mass (ME) was inversely dependent on soil fertility, in such a way that values associated with the highest agrobiological effects for the low-fertility acrisol (35 mg·g-1 soil) were superior to values found in low and high fertility cambisol soils (20 a 22 mg·g-1 soil). mycorrhizal inoculation in the most adequate substrate by soil type significantly increased nutrient content, from 10 to 150 %. arbuscular mycorrhizal fungi with better response per soil type were: acrisol – dystric cambisol, Glomus clarum, Glomus spurcum; Glomus fasciculatum.

The objective of this study was to evaluate the effect of inoculating arbuscular mycorrhizal fungi (HMA) and soil:earthworm humus ratio on coffee postures in acrisol, dystric cambric and eutric cambisol soils. Three experiments were carried out under nursery conditions under a completely randomized factorial design, evaluating morphological, fungal, and nutritional variables. Results demonstrated that inoculation with HMA was effective, accomplishing increases in leaf area between 6 and 140 % compared to non-inoculated plants. Mycorrhizal efficiency of inoculated lines was defined by soil fertility and soil:earthworm humus ratio. Endophyte mycorrhizal mass (ME) was inversely dependent on soil fertility, in such a way that values associated with the highest agrobiological effects for the low-fertility acrisol (35 mg·g-1 soil) were superior to values found in low and high fertility cambisol soils (20 a 22 mg·g-1 soil). mycorrhizal inoculation in the most adequate substrate by soil type significantly increased nutrient content, from 10 to 150 %. arbuscular mycorrhizal fungi with better response per soil type were: acrisol – dystric cambisol, Glomus clarum, Glomus spurcum; Glomus fasciculatum.

 

LADDER-FORM CANOPIES FOR TOMATO ROWS ORIENTED EAST- WEST

DOSELES ESCALERIFORMES CON HILERAS DE PLANTAS DE JITOMATE ORIENTADAS EN DIRECCIÓN ESTE-OESTE

T. Méndez-Galicia; Felipe Sánchez-Del Castillo; Jaime Sahagún-Castellanos; Efraín Contreras-Magaña

Keywords: Lycopersicon esculentum Mill., high density, prunning, trimming, hydroponics, planning arrangement.

10.5154/r.rchsh.2004.01.010

Received: 0000-00-00
Accepted: 0000-00-00
Available online: 2016-07-01
Pages:185-182

With the objective of increasing yield per unit area for tomato under hydroponics in the greenhouse, we compared different plant arrangements consisting of ladder-shaped (ladder-form) and uniform canopies, against a commercially already validated uniform canopy. A randomized block design with nine treatments and four replications was used; each experimental unit consisted of an area of 1.56 m2. Both greenhouse and plant rows had an east-west orientation. Ladder-form canopy treatments were established by placing sets of three rows of plants, each plant trimmed to a different number of clusters, or four rows of plants, each plant trimmed to three clusters, but placed in containers at different heights. In the first case we obtained four treatments (43, 49, 53, and 56 cluster·m-2) and for the second case two treatments (50 and 66 cluster·m-2). The two treatments for uniform canopy and the control were generated with four rows of plants with three racemes each (resulting in 50, 66, and 30 cluster·m-2, respectively). Aside from yield per unit area, we evaluated the number of fruits per unit area, fruit average weight, and leaf area index (LAI). Yield and LAI were significantly higher when using ladder-form canopies made from plant rows trimmed at different numbers of cllusters. Yield was 27.3 kg·m-2, compared to only 18.3 kg·m-2 from the uniform canopy control; while LAIs were 5.9 and 2.5, respectively. We conclude that plants managed in a ladder-form arrangement had better yield per unit area than the uniform canopy control due to harvesting of a higher number of clusters and, thus, fruits per unit area with a small reduction in fruit average weight.

With the objective of increasing yield per unit area for tomato under hydroponics in the greenhouse, we compared different plant arrangements consisting of ladder-shaped (ladder-form) and uniform canopies, against a commercially already validated uniform canopy. A randomized block design with nine treatments and four replications was used; each experimental unit consisted of an area of 1.56 m2. Both greenhouse and plant rows had an east-west orientation. Ladder-form canopy treatments were established by placing sets of three rows of plants, each plant trimmed to a different number of clusters, or four rows of plants, each plant trimmed to three clusters, but placed in containers at different heights. In the first case we obtained four treatments (43, 49, 53, and 56 cluster·m-2) and for the second case two treatments (50 and 66 cluster·m-2). The two treatments for uniform canopy and the control were generated with four rows of plants with three racemes each (resulting in 50, 66, and 30 cluster·m-2, respectively). Aside from yield per unit area, we evaluated the number of fruits per unit area, fruit average weight, and leaf area index (LAI). Yield and LAI were significantly higher when using ladder-form canopies made from plant rows trimmed at different numbers of cllusters. Yield was 27.3 kg·m-2, compared to only 18.3 kg·m-2 from the uniform canopy control; while LAIs were 5.9 and 2.5, respectively. We conclude that plants managed in a ladder-form arrangement had better yield per unit area than the uniform canopy control due to harvesting of a higher number of clusters and, thus, fruits per unit area with a small reduction in fruit average weight.