The objective of this research was to estimate the genetic parameters of the husk tomato (Physalis ixocarpa Brot.) CHF1-Chapingo cultivar. Two hundred maternal half sib families were evaluated under three environments, in a complete randomized block design with two replications, and 22 plants by experimental plot. The narrow sense heritability of the 13 studied traits varied between 37.1 and 57.8 %; the genetic additive variation coefficient presented values between 8.2 and 24.4 %; for the total yield, values were 37.5 and 10.4 %. The fruit number and weight at the first harvest, and the total plant fruit number were the most important yield components. High additive genetic correlation absolute values were found for the total yield with: the first harvest yield (0.67), fruits per plant in the first harvest (0.50), total fruits per plant (0.58), fruit set number (0.38), and first stem bifurcation height (-0.49).

Genetic diversity of grain legumes and its cropping system was determined to identify indigenous cultivars used by farmers at the Chontalpa region, Tabasco State, Mexico. Direct interviews to 536 farmers were conducted from January to May, 2002. Nineteen indigenous bean populations were collected among the farmers in the region. Eight of them belong to the Phaseolus vulgaris specie and the rest to the Vigna unguiculata specie. Only 30.6 % of the farmers grew indigenous cultivars. The largest genetic diversity is preserved in the Cárdenas County. Monoculture was the predominating bean cropping system in the region; it was used by 65.8 % of the farmers interviewed. Jamapa (black bean) is the main cultivar used in the monoculture system. Cropping area by farmer ranged from 0.1 to 1.4 ha. A 34.5 % of farmers do not use chemical fertilizers and 50.7 % of them mentioned that only foliar fertilization during the flowering initiation period is made. Chemical pest and disease control is made by the 100 % of the farmers interviewed. Only in Cunduacán County, 60 % of the bean production is for selling, in the rest, bean production is for self-consumption. Regional farmers have a precise knowledge of indigenous cultivars. This diversity needs to be valued for its conservation and improvement.

Peach (Prunus persica L. Batsch) of Ana cultivar were obtained from seed grown trees at the commercial orchard “San Carlos” in Aguascalientes State, Mexico. It has high fruit production and good commercial quality. Selection is a plant breeding method commonly used in fruit crops. It is based on the identification of outstanding individuals, coming from seed propagation, with a desirable trait as selection criteria. The objectives of this research were to characterize and to evaluate a group of Ana type peach selections. The study was conducted from 2000 to 2004 at the commercial orchard “San Carlos”, in the Asientos County, Aguascalientes State. Plant phenology, fruit yield and quality were evaluated on twenty one selected trees originated from seed. For the statistical analysis of fruit yield and fruit number, a randomized complete block design was used, while for fruit characteristics a split plot design with 10 replications was used. Least Significant Difference was used for mean comparisons (P< 0.05). The average phenological behavior of the five years of evaluation was as follows: beginning of flowering, sprouting and harvest was from the Julian day 24 to 33; 28 to 39 and from the day 221 to 227, respectively. Fruit yield per plant varied from 16.1 to 41.1 kg; fruit number was from 128 to 308 fruits tree-1, fruit weight ranged from 84.19 to 177.59 g; polar and equatorial diameter were from 4.89 to 6.51 cm and 5.23 to 6.91 cm, respectively. Pulp thickness was from 1.64 to 2.44; total soluble solids were from 10.53 to 12.75 %. Finally, polar, equatorial diameter and seed weight were: from 2.93 to 3.38 cm, 1.99 to 2.38 cm and 4.48 to 6.77g, respectively. The outstanding selections were: S-59, S-67, S-65 and S-68.

With the objective of evaluating the response of the growth of tomato seedling (Lycopersicon esculentum Mill) to the biosólidos application in a Ferralitico Red compacted soil, behaved an experiment in pots. In this work the response of the leaf area, seedling height, shoots diameter, radical longitude and dry weight for organs and total of the tomato seedling to cultivated in a soil treated with 135 g of biosolids for kg-1 of soil was compared with those developed in the natural soil and in the soil treated with mineral fertilizer (urea), to reason of 150 kg of N.ha-1. The results showed that indicators related with the growth of the seedling responded positively to the biosolids application, where an evident increment was observed in the magnitudes of all the evaluated variables, with similar and superiors results to those of the treatment with mineral fertilizer, what indicates that these residuals have potentialities to be used in systems of seedling production in cultivations that need to be taken to the field.

Sapote mamey is a fruit tree grown in the southwest region of Morelos State, Mexico. Its fruit have a great commercial potential, however, there are none Mexican commercial cultivars. In this study, the fruit characteristics variability was evaluated, to use it later as a basis to continue studying the selection of potentially useful materials for that region. Nineteen materials were evaluated; based on fruit dimensions, fruit length/diameter ratio; fruit, seed, and pulp weight, as well as peel and pulp thickness, the pulp color components (luminosity, chrome and hue), total soluble solids, and total soluble sugars. Fruit, peel, and pulp weight were the variables with the highest variation coefficient, between 25 and 41 %, which together with seed number (CV 46 %) were responsible for the integration of 6 groups. Groups 1, 2 and 4 were created with the highest horticultural potential genotypes. Group 1 is formed by small fruits, ovoid (L/D; 1.5) and with the highest values in total soluble solids, and total soluble sugars (24.5 ºBrix and 123.4 mg·g-1); fruits in group 2 are also small, ovoid (L/D 1:6) with just one seed, color pulp closer to red (hue angle 66.8); and fruits from group 4 have medium size, orange pulp color (hue angle 69.9) and the highest values of all the materials evaluated in total soluble solids and total soluble sugars (30.2 ºBrix and 131.2 mg·g-1). The presence of small (300-500 g) and medium (500-700 g) fruits, suggests the existence of potential materials for different markets (fresh and processed).

The goal of this study was to know the effect of late irrigation deficit and crop load on Empire/M.9 apple. Two levels of soil moisture were used: normal irrigation and two drought cycles during the final phase of fruit growth, and three levels of crop load: 1, 3 and 6 fruit·cm-2 of trunk area. The effect of treatments on fruit quality, trunk area, yield and bloom return in four years old potted trees was observed. Results showed that late irrigation deficit do not have any effect on yield, fruit size, and fruit number. With these results it is possible to save water, stopping applying late irrigation in the phase III of fruit growth. Trunk area was affected by late irrigation deficit, but flower density is increased.

Acetyl salicylic acid and Bacillus subtilis, as resistance promoters, were evaluated on Cucurbita pepo cv. Zucchinni grey infected by Cucumber mosaic virus (CMV). A complete randomized experimental design with five treatments and eight replications was established under greenhouse conditions: Bacillus subtilis applied to soil, B. subtilis applied to leaves, B. subtilis applied to soil and leaves, acetyl salicylic acid applied to leaves, and a Control (without any treatment). Twenty days-old plants were mechanically inoculated with Cucumber mosaic virus (CMV) and 15 days after the inoculation, fresh plant tissue weights, and viral concentration obtained by DAS-ELISA test, were evaluated. Results showed that plants inoculated with B. subtilis applied to soil and those treated with acetyl salicylic acid had significantly more fresh plant tissue weight compared with Control (P£0.05). Plants of all treatments treated with B. subtilis (to soil, leaves and to soil and leaves) had a significant lower viral concentration compared with Control (P£0.05) in the DAS- ELISA test.

The strawberry fruit flavor depends on its sugar, amino acid, and organic acid content. Up to now, the effect of nitric nutrition and irrigation systems on these compounds is not well characterized. The objective of this work was to identify and to quantify the carbohydrates, amino acids, and organic acids content in strawberries cultivated at different levels of nitric fertilization, under two irrigation systems. Nitrogen was applied as Ca(NO3)2 at concentrations of 0, 3, 9 and 20 mM in the irrigation water and drip and furrow irrigation systems were used. The carbohydrate and the amino acid content increased at 3 mM in drip system and 9 mM in the furrow system, compared with the unfertilized treatment, but did not increase further at 20 mM nitrogen. The organic acids content decreased as the nitrogen fertilization increased. Therefore, an excessive use of fertilizer and irrigation water does not enhance the content of the compounds related with the sensorial quality of the strawberry.

Apple production in Querétaro State, Mexico occurs under irregular rainfall conditions, in highly steeped slopes, with a deficient orchard management, the occurrence of unfavorable climatologic events, and a seasonal variation of the ripening of main cultivars, causing unmarketable poor fruit quality. A viable solution is the introduction and selection of high quality and early ripening varieties adapted to local conditions. Ripening season and fruit quality of 20 apple new hybrids and varieties, based on fruit diameter, fruit weight, firmness, total soluble solids (TSS), and total titratable acidity (TTA), were studied. Genotypes 401 (‘Tropical Beauty’ x ‘Princesa‘, red color) and 467 (‘Anna’ x ‘Liberty’, yellow color) ripened the earliest, on July 8; other six genotypes (‘Rayada’, 424, 428, 421, SM4 and SM5) ripened before August 1st. The highest sized of these was 428 (‘Anna’ x ‘Gala’, red blushed, 8.5 cm diameter and 39 % of fruits in the “Extra” category of the Mexican standards). Other outstanding materials were 467 (7.0 cm) and ‘Rayada’ (6.9 cm). Within the midseason ripening accessions, 436 (‘Anna’ x ‘Gala’) and 429 (‘Anna’ x CLR9T10) were outstanding and higher than ‘Golden Delicious’ in diameter with 7.8 cm and 7.4 cm, respectively. Besides, the first one produced 27 % of fruits in the “Extra” category with a TSS (16.3 %) superior to ‘Golden Delicious’ (13.4 %) and to ‘Red Delicious’ (12.7 %). Within the late ripening genotypes, ‘Lourdes’ showed similar quality to those of local cultivars.

The effectiveness of four systemic fungicides (azoxystrobin, 150 g·ha-1; dimethomorph, 225 g·ha-1; fosetil-Al, 2 kg·ha-1; y triforine, 285 g·ha-1) for downy mildew control (Pseudoperonospora cubensis) was evaluated in cantaloupe melon early sown at the Yucatan State, Mexico. The fungicides were sprayed at 36, 52 and 67 days after transplant (dat), and the disease intensity at 43, 60, and 75 dat, yield components, and fruit soluble solids concentration, were assessed. No significant difference on disease incidence (5.6-12.5 %) was observed at 43 dat. Disease incidence (73.3 %) on dimetomorph treated plots was significantly lower than in the control plots at 60 dat. Disease incidence reached 100 % in all treatments in the last recorded date, 75 dat. Disease severity, measured with Horsfall-Barratt scale, was significantly lower in dimetomorph treated plants in the three dates evaluated. The final disease severity was significantly lower in plants treated with dimetomorph or fosetil-Al, in which 85 and 75 %, respectively, less area under the disease progress curve (AUDPC) was observed than in the control plants. These fungicides also induced the highest number of fruits per plot, mean individual fruit weight, and total fruit yield. The fruit soluble solids concentrations were not significantly different among treatments. A linear negative effect (r2=0.84) of the disease severity (AUDPC) on the total fruit yield was found.

Cactus pear fruit prices drop significantly during August and September in North-Central Mexico because harvest peak is concentrated on those months. Harvest delay is an option to alleviate this problem and it was the aim of the research conducted. Four-year-old cactus pear trees cv. Cristalina were used in this trial. The treatments were: 1) leaving the normal development of the first vegetative and reproductive flux, which was considered as control, and 2) inducing a second vegetative and reproductive flux. The second treatment set back the harvest by 45 days, increased weight and flesh firmness of fruit, but yield was reduced by 65 % compared with control. After four weeks in storage, flesh firmness and dry mass concentration were higher in out of season fruits. It is possible to delay the harvest period of the cv. Cristalina, however, additional research work is needed under different environments and other cactus pear cultivars with high commercial value.

‘Autumn Bliss’ raspberry phenology was studied at Guerrero, Chihuahua State, Mexico. In this trail 500 plants of raspberry, bare root system, were planted in the first week of April, 2000. Plantation distances were 1.5 x 0.5 m between rows and plants respectively, in 10 rows with 50 plants each one. Before plantation 60 t·ha-1 of dry bovine manure was applied. Furrow irrigation system was used during the first 30 days. Later on drip irrigation was installed with 1 m between emitters. The new regrowth was from the root system, and from budwood, 30 days after plantation. Primocanes fruiting length was 180 cm. Bloom initiation was in the second week of July, after more than 90 days of growth, with no probabilities of frost damage. Primocanes fruiting number was 6.7 per plant. Period from flower to fruit harvest was between 33 and 36 days. First harvest was on the first week of August, and the last one was late October, just when the frost period started. Fruit size was from 2.6 to 3.6 g. Yield recorded was 778 g·p-1, estimating 10.373 t·ha-1.