Changes in some polysaccharides during postharvest ripening of ‘Kent’ mangoes were evaluated in the present study. Fruit at physiologi¬cal maturity stage were stored to simulate marketing conditions (20 ± 2 °C, 85 % relative humidity) until reaching the ripening stages 2, 3, 4 and 5 (according to the standards of Empacadoras de Mango de Exportación, A. C.). Changes in firmness, starch, pectin, hemicellulose and cellulose were determined. Polysaccharides were obtained from the alcohol-insoluble fraction of the mango flesh. Fruit showed a total firmness loss of 93 % from the ripening stage 2 to 5, which was progressively reduced in 40, 44 and 9 % when the fruit reached the stages 3, 4, and 5, respectively. In that order, the rate of softening was defined as initial, intermediate, and late. During the initial fruit softening, the content of starch was reduced by 90 % and the total sugars by 44 %, while the total uronic acids increased by 39 %. The total concen¬tration of arabinose was maintained without significant changes in the different ripening stages at levels of 250 mg•100 g-1 fresh weight; however, a reduction of 50 % in glucose and galactose occurred during the initial softening. The water soluble-fraction was the prevalent pectin fraction with a composition near to 2:1 in the uronide:sugar ratio. During the softening of ‘Kent’ mangoes, changes in solubility and polymerization degree of pectin and hemicellulosic polysaccharides were observed.

The hawthorn, Crataegus spp., is grown in seven states in Mexico. Its fruit is affected by Conotrachelus crataegi, an insect that bores into its flesh and stones, causing damage and loss of quality. In this research, we evaluated different parts of the host, male and female quince curculios, and combinations thereof, as potential sources of attraction for adults. We also studied female oviposition preference in eight fruit accessions from five hawthorn species. Results of bioassays in two-way olfactometers indicated that the fruits were the best adult attractant source (P

In 2006 rose cultivation in the municipalities of Tenancingo, Villa Guerrero and Coatepec Harinas covered an area of 415 ha, representing a significant production value equivalent to 688,722,450.00 pesos. This crop is attacked by white root rot disease, resulting in plant losses since control methods are ineffective. The objectives of this study were to identify the fungus species associated with white root rot disease in rose plants and evaluate its sensitivity to fungicides. Samples of plants with infected roots were collected in Tenancingo, Villa Guerrero and Coatepec Harinas in the State of Mexico, obtaining nine strains. The fungicides quintozene, benomyl, fluazinam and thiophanate methyl were evaluated at doses of 1 g.L1, 0.6 g.L-1, 0.5 ml.L-1 and 0.6 g.L-1, respectively. The fungus associated with white root rot disease presented mycelium with pyriform swellings before the septum; as symptoms, mycelial cords were found on the root and neck of the plant. The fungus was identified taxonomically as Rosellinia necatrix Prill. (Dematophora necatrix (Hart.) Berl.), which was confirmed by mole¬cular analysis. The strains T1GRJ, T2GRJ and T3GRJ of Tenancingo and the strains VG1GRJ, VG2GRJ, VG3GRJ and VG4GRJ of Villa Guerrero were insensitive to the fungicide quintozene, while with the fungicides benomyl, thiophanate methyl and fluazinam no mycelial growth appeared. The strain T4GRJ of Tenancingo showed sensitivity to all fungicides. The strain CH1GRJ of Coatepec Harinas was insensitive to quintozene and presented slight growth with fluazinam, while with benomyl and thiophanate methyl there was no growth.

The purpose of this study was to evaluate the antifeedant effect and toxicity of Azadirachta indica, Piper auritum and Petiveria alliacea ex¬tracts on Spodoptera exigua larvae under laboratory conditions and in an open-field crop of organically-grown grape tomatoes var. Santa. The work was carried out with hexane and methanol extracts of A. indica seeds and P. auritum and P. alliacea leaves applied in different concentrations against 4th-stage S. exigua larvae. The variables evaluated were feeding deterrence index (FDI), feeding suppression in¬dex (FSI), mortality rate and LC50. The strongest feeding deterrent effect was found in the methanol extract of Azadirachta indica, followed in descending order by that of P. auritum and P. alliacea. The mortality rates for A. indica, P. auritum and P. alliacea were 38.88, 28.8 and 21.22 %, respectively, under laboratory conditions; the same trend was found in the field. The LC50 showed that the methanol extract of A. indica was the most potent (4.03 ppm), followed in effectiveness by that of P. auritum (42.08 ppm). In the field, the LC50 of the methanol extracts of A. indica, P. auritum and P. alliaceae were 9.61, 21.21 and 104.1 ppm, respectively.

Mexico has a great diversity of plants, many of them with ornamental potential that has not been used due to the lack of information. There is a world-wide tendency to rescue wild plants with ornamental potential to be included in the design of green spaces. The objective of this study was to develop and apply a methodological matrix for the selection of native wild species with ornamental potential. A survey and collection of herbaceous species was carried out in eight municipalities in central Veracruz (Huatusco, Tepatlaxco, Coscomatepec, Paso del Macho, Amatlán de los Reyes, Cuitláhuac, Tezonapa and Zongolica) in areas little disturbed. Herbaceous species with attrac¬tive characteristics of foliage and flowers were collected. A total of 18 species belonging to 10 families and 16 genera were identified, the majority of them has not been used in landscape design. Based on the methodology developed, five plants had high ornamental potential. Ruellia coerulea Morong, Cosmos sulphureus, Zinnia elegans L., Salvia coccinea Buc´hoz ex Etl. and Lantana camara L. had the highest scores of potential for ornamental use.

The objective of this work was to characterize cactus pear production system in Axapusco, Estado de México by performing surveys among farmers and interviews to key participants. Most are peasants and have parcels in “ejidos” (73 %). The production system shows high variability. They plow the surface (37 %) or the subsoil (34 %). The typical density is 600 to 700 plants per hectare (38 %). The com¬mon distance between plants is 4.0 m by 4.0 m (55 %). The white cactus pear (Opuntia albicarpa) is predominant in the region (74 %). Two-thirds of the farmers use manual weed control. Fresh cattle manure is used by 54 % of the farmers. Most farmers do not receive any technical assistance (96 %). Furthermore, a large proportion of the farmers said they do not receive any governmental subsidy (71 %). The most important problem for farmers is the control of pests and diseases (34 %); followed by low fruit price and orchard management (both 21 %). The lack of technical knowledge is behind those problems. Several strategies are required to solve these problems. Highlighting, that farmers have to compost of the manure, use bio-insecticides for pest control and improve their organization.

In agriculture under controlled environment, soil has been replace by substrates due to physical, chemical and biological limitations. The use of materials coming from agro industrial wastes or byproducts facilitate the use of low cost substrates and enable a positive ecolo¬gical impact, which is the case of the forest industry that produce a large volume of pine sawdust with potential as a substrate. Physical properties of the substrates are the most important, because once the crop has been settled, it can hardly be modified and it must remain constant throughout crop cycle. The objective of this work was to evaluate the variation in physical properties of the substrate formed by a sawdust/volcanic rock mixture during several crop cycles to determine the feasibility of their use. For this purpose, 10 treatments were used, which consisted of the com¬bination of three volcanic rock particle sizes (≤3, 3-6 and 6-12 mm) and three sawdust/volcanic rock ratios (90/10, 80/20 and 70/30) plus a treatment 100 % pine sawdust. These treatments were tested during five continuous tomato crop cycles (thirty months). Total porosity, particle size, moisture retention capacity, air capacity and bulk density were measured at the end of each cycle and also from the original substrate. Little variation in bulk density was observed, but total porosity, moisture retention capacity and air capacity decreased gradually during the five tomato crop cycles. Air capacity was the physical characteristic that showed greater variation, showing values below the appropriate after 24 months of cultivation.

This work was carried out in order to compare propagation capacity and quality of Mexican strawberry varieties (CP-Jacona and CP-Zamorana) and foreign commercial varieties (Festival and Albion). The four varieties were established in two nurseries located in Mi¬choacán, Mexico at different altitudes: Tanaquillo (1,700 m) and Zirahuén (2,228 m). Eight mother plants and eight daughter plants were sampled as replications. Number of crowns, number of runners and daughter plants per mother plant were the variables studied. Root starch content and fresh and dry plant weight were recorded of the daughter plants. The statistical analysis was performed using the stu¬dent’s t-test with 5 % significance level. The Mexican variety ‘Festival’ produced more runners, crowns and daughter plants in the nursery of Zirahuén, compared to other varieties; however, the starch content was higher in the Mexican varieties. In the nursery of Tanaquillo, both the ‘Festival’ and ‘CP-Jacona’ varieties showed higher number of daughter plants; however, the starch content in the ‘Festival’ variety was higher than in the ‘CP-Jacona’ variety. In the nursery of Zirahuén, the starch content of daughter plants was higher than in the nursery of Tanaquillo, but the number of daughter plants produced was notably higher at the nursery of Tanaquillo. At the nursery of Zirahuén, the ‘CP-Jacona’ variety had a lower capacity of runners and daughter plants production but these plants showed greater starch content but dry weight of daughter plants was similar to the USA varieties. At the nursery of Tanaquillo, the Mexican varieties were better in the production of daughter plants than the ‘Albion’ variety.

A weather model was evaluated to estimate the hourly time temperatura and relative humidity inside of a zenithal ventilated type green¬house, as a function of the weather outside of the greenhouse. The study was carried out during the Winter of 2008-2009, in a comercial greenhouse with tomato production, located at Tlahualilo, Durango, Mexico. The model considered the effect of natural ventilation. The results of the evaluation for two non consecutive days showed a good estimation of the air temperature, and a reasonable good estimation of relative humidity. Some adjustments are still required to improve the quality of the model.

In the present research six alternative growth media made of filter mud were evaluated, which suffered biological stabilization processes, alone or mixed with cattle manure and its subsequent use for the production of tomato seedling, in order to promote the use of other materials different from the peat. Research was conducted in three stages: 1) the elaboration of 7 treatments by means of drying, was-hing and drying, composting and vermicomposting of filter mud, alone or mixed with cattle manure, and treatments peat/perlite-based used as control treatment; 2) treatment characterization (growth media) by means of their physical and chemical properties; 3) seedlings production, recording the development and quality of seedlings. Treatments coming from dried and washed filter mud showed physical characteristics similar to the control treatment. Treatments exposed to a composting process showed variable physical characteristics according to the source material. Treatments coming from the vermicomposting process showed a low porosity and water retention. In general, all treatments showed good chemical conditions. As for seedlings production, the treatment based on dried filter mud showed the highest seedling quality.