Prohexadione calcium (P-Ca) increases the levels of soluble solids, anthocyanins and aromatic compounds in deciduous fruits. In vegetable crops the effect of P-Ca is less documented. In this study it was evaluated the changes originated by P-Ca on total antioxidant capacity, lycopene content and catalase and peroxidase activity in Floradade tomato (Lycopersicon esculentum Mill.) different concentration (0, 125, 175 and 200 mg·liter-1) with one or two applications of P-Ca were evaluated. The first application was conducted when plants showed floral tissue initials and the second 15 days after. The results showed that P-Ca increased (P≤0.01) the total antioxidant capacity in fruits under shoulder stage. The lycopene concentration increased in fruits from plants sprayed with any P-Ca concentration, being higher at the stage of green shoulder. The catalase and peroxidase enzyme activity also showed an increase (P≤0.01) with the application of P-Ca.

The aim of this study was to identify salinity tolerant avocados materials useful as rootstocks. Embryonic axes of criollo and ‘Hass’ avocados were planted in vitro on Murashige and Skoog medium at 100 % of its nutritional composition in induced saline environment with NaCl and CaCl2. Five levels of each salt were tested (0.1, 0.3, 0.5, 0.7, 0.9 %), as well as their combination at 1:1 ratio. The germination, seedling emergency, rooting plant growth and plant surviving of avocados were studied. Criollo achieved 21 % of seed germination, and 26 % of seedling emergency, higher than ‘Hass’ avocados, with 50 % in each one of plant growth variables and 10 % of plantlets survival. The embryonic axes were more deteriorated with NaCl treatments than with CaCl2 treatments and NaCl:CaCl2 treatments. The in vitro technique helped to determine, after 65 days of culture than criollo avocados were more stress saline tolerant than Hass.

Oaxaca state of Mexico has a number of zones with ‘water chilli’ pepper, (Capsicum annuum L.) which differ in their physiographic and agro-ecological characteristics. With the objective of to generate knowledge that contributes to the conservation and genetic improvement of the productive potential of this species of chilli, in eight zones, germplasm was collected and characterized in situ during 2006 and 2007 under a completely random sampling using two locations and ten plants per location, which used the guide to the International Plant Genetic Resources Institute. To decrease the environmental effect of the collection sites, was carried out ex situ morphological characterization, during 2008, under greenhouse conditions, therefore the eight collections (360 plants) were grown under an intensive system in hydroponics, in a design completely randomized. The information was extracted from eight samples taken every fifteen days. From analysis of variance and covariance were identified descriptors root, stem, flower, fruit and seed, to distinguish collections. In the cluster analysis of cluster (Ward minimum variance) and describe the characteristics of the grouping responsible (principal components analysis) were identified three groups and Ocotlán germplasm as promising for a process of genetic improvement by to present the fruits with the characteristics most desirable for the market.

In order to identify good commercial maize hybrids and population densities for huitlacoche production in greenhouse conditions, two experiments were carried out (2005 and 2006) in hydroponics. The first one included four hybrids in a population density of 62, 500 plants·ha-1. In second experiment seven hybrids were evaluated at 166, 666 plants·ha-1. Every hybrid was inoculated with its respective fungus strain, obtained of each hybrid. In both individual assays and in the combined analysis of two experiments, the best hybrid was 30G40 with production of 1,649.2 kg·ha-1, 7,923.30 kg·ha-1 and 4,786.20 kg·ha-1 (combined); derived from their percentage of incidence of 23.67, 52.41 and 38.04 %, and from their severity index of 52.48 and 47.21and 38.04, respectively. In the combined analysis, the yield of huitlacoche was higher at 166,666 plants·ha-1 (3,592.10 kg·ha-1) than at 62,500 plants·ha-1 (960.2 kg·ha-1), instead of the production of fungus per plant was similar in both densities (0.02 kg·planta-1) of 30G40 hybrid.

Tomato seedlings were sprayed with low concentration of salicylic acid (SA) as to estimate its effect on root and shoot growth. The seedlings were cultivated under greenhouse conditions in pots with a mixture of cosmopeat and agrolite (2:1) that was fertilized with a solution of 380mg.liter-1 of N, P and K and kept well watered. SA was spread at any of the following SA concentrations 1.0, 0.01, and 0.0001mM or water as a control treatment. SA was applied at 9 and 13 days after the emergence of the seedling and 7 days afterwards they were harvested for the measurements. Pots were arranged in a totally random design with 24 replicates per treatment . The results showed that SA increases significantly height, leaf area, fresh and dry weight of the shoot as well as length, perimeter and area of the root. AS at 1mM increased root length by 43%, 14.8% shoot size and 38.6% leaf area as compared with the water control. Doses-response curves are presented for the measurements taken.

Injuries of Lygus lineolaris nymphs on strawberry fruits, and the efficacy of two B. bassiana strains, L-BB (50 and 100 g·ha-1) and Bblygus04 (100 and 200 g·ha-1), were evaluated against nymphs of this pest in a commercial strawberry plot. Treatments were compared with the efficacy of Endosulfan (1.5 litros·ha-1) (standard insecticide), and an untreated control in a randomized complete block design with four replications. There were significant differences in the efficacy between treatments (P

The Southern false serviceberry (Amelanchier denticulata (Kunth) Koch) is a fruit-bearing shrub native to Mexico, and there are not enough studies about the use, distribution, and diversity. This research aimed to make a distribution model and eco-climatic characterization as well as current and future models of suitable areas for cultivation of A. denticulata using Geographical Information Systems (GIS). The southern false serviceberry was distributed mainly in central Mexico. Three eco-climatic groups were found; group 1 showed climate C, group 2 climate A(C), and group 3 climate Bs. The most suitable regions of cultivation were Guanajuato, Queretaro, and Hidalgo. This research will serve as basis of planning the best conservation strategy of A. denticulata genetic resources and to design the correct way of collection. The three different climatic groups should have diverse germplasm, which is important collect from each group. The best regions to establish in vivo germplasm bank are northeast Guanajuato, central and southern Queretaro, and southern Hidalgo.

To evaluate, physiotechnicaly and agronomicaly, four different production systems of tomato using two hybrids, the growth and yield per plant and area unit were compared. The plants were conducted to a single stem and trimmed two leaves above the third cluster. A randomized complete block experimental design with four replications was used with a factorial arrangement of treatments. The production systems were: Canopy with a stair shape formed by four rows of plants of the same age located to different height; canopy with crop cycles overlapped in a stairs shape; uniform canopy formed by four rows of plants and uniform canopy formed by three rows of plants, and genotypes were ‘Sun Lider’ and ‘Pick Ripe’. Several growth indicators were evaluated every 30 days and, at the final of crop cycle, the yield and their primary components. The production system with stair shape canopy formed with plants at different height, maintained high assimilation net rates along the crop cycle and presented the highest yield (2.35 kg/plant or 16.15 kg/m2 in a period of four months from transplant to final harvest, and the highest fruit medium weight (140 g); in number of fruits per plant the highest value was for the overlapped system (19.18 fruits). The genotype ‘Sun Lider’ with 2.25 kg/plant, overcame ‘Pick ripe 461’ (2.12 kg / plant).

In order to know the effect of trellis type on the production of snap bean, were sowing in Montecillo Mexico, the variety of Hav-14, of snap bean and the cv. Victoria of sunflower, plants at densities of 6.2 plants·m2, for unicultivos and 12.4 plants·m2 for the combination sunflower- snap bean. where sunflowers served how trellise for snap bean and to snap bean in unicultivos the trellises was of wood whith a fertilizer of 100-100-00 NPK. The treatments was: snap beans in unicultivo (FU), snap bean with sunflower whitout cut (FGS), snap bean with sunflower cutting (FGC) and sunflower unicultivo (GU). Variables evaluated were: yield, Harvest index, length of snap bean, index leaf area, Leaf area. The results indicate that production of snap bean in unicultivo, super to agrosistem snap bean combined with sunflower whitout cut and cut to index leaf area, leaf area.

The objective of this study was to compare growth and yield of 17 bell pepper varieties (4Ever, Cadia, Conan, Cyrus, Diego, Gandal, Giacomo, Grandisimo, Itzel, Magi, Magno, Moonset, Oberon, Orion, Triple4, Triple Star and Valencia) under two population densities (four and six plants m-2) and managed with a cultivation system that involves pruning the terminal buds above the fourth bifurcation. The experiment was conducted in greenhouse under soilless culture. A randomized block design with split plot arrangement was used. The population densities were considered in the large plots and the varieties in the small plots. The total time from transplant to the end of harvest was less than four months. With higher population density, total dry weight, percentage of fruit set, fruit number and fruit weight per plant decreased significantly; in consequence, the yield per area was the same in both densities. Under the cultivation system used, Orion produced the highest yield; fruit weight per plant was the most important yield component.