According to producers from Valle del Mezquital, Hidalgo, the use of wastewater improves postharvest quality of horticultural products; however, there is not enough scientific evidence that prove it. Postharvest quality in tomato fruits produced with waste water (WF) and well water (WWF) in hydroponic systems was evaluated. Fruits were harvested and stored during 10, 20, 30 and 40 days, under the following conditions: 4 °C with 90 % RH; 10 °C with 82 % RH and 20 °C with 62 % RH. Hue angle, total soluble solids, titratable acidity, firmness, weight loss and pH of the fruit were evaluated at the end of each period. Fruits refrigerated at 4 °C and 10 °C during different storage periods showed differences in hue angle (P ≤ 0.05): hue values were lower in WF than in WWF. This indicates that WF fruits were redder. °Brix in non- refrigerated fruits during 10, 20, 30 and 40 storage days were greater in WF than in WWF. Total soluble solids were higher in WWF than in WF at 10 °C during 30 and 40 storage days and at 4 °C during 30 storage days. Titratable acidity had differences only in refrigerated fruits at 4 °C during 20 storage days: WWF showed higher titratable acidity than WF. Firmness, weight loss and pH of the fruit did not show differences for the factor type of water.

The use of synthetic varieties (SVs) derived from single (SynSC) or double (SynDC) crosses is a way of avoiding the high seed cost of hybrid maize (Zea mays L) and onion (Allium cepa L.) varieties, among others. In addition, these SVs could be used to more economically predict the genotypic means (GMs) of the SVs derived from the hybrid parental lines (SynL). It is known, however, that the inbreeding coefficients (ICs) of the SynL, SynSC, and SynDC derived from the same lines can differ, but the reason why is unknown. This lack of knowledge makes it difficult for the breeder to improve the representation of the SynL through the SynDC and SynSC and thereby to improve the estimation of the SynL GM. The objective of this study was to determine the reason why the SynL, SynSC, and SynDC can differ. From unrelated L lines whose IC is FL, L/2 single (SCs) and L/4 double crosses (DCs) were derived; and each line, SC, and DC were represented by m individu- als. By randomly mating each set of parents, the SynL, SynSC, and SynCD were formed. It was found that the genotypic arrays of the three SVs differ because with the same 4 initial lines the number of non-identical by descent genes contributed to the genotypic array is larger as fewer lines are involved in a parent [lines (1), single crosses (2), and double crosses (4)]. Thus, the ICs of SynL and SynDC are the smallest and largest, respectively; and it is expected that the GMs show the opposite ordering. In addition, as m and FL are smaller the differences among the genotypic arrays of the SVs are larger. On the contrary, when the L lines are pure, the genotypic arrays of SynL and SynSC are equal, and their IC must be equal as well. To be equal to SinL, SynDC requires, in addition, a large m. However, even with FL < 1, as m is larger the genotypic arrays of SynSC and SynDC tend to the genotypic array of SynL, although slowly, particularly for SynDC.

There were 36,166.36 ha planted with ‘Tahiti’ lime (Citrus latifolia Tan.) in Veracruz, Mexico in 2010, which produced 437,460.80 tons of fruit valued at 88.07 million dollars. Because rootstocks influence vegetative growth, citrus fruit yield and quality, depending on the species of rootstock, soil type and climate where they are cultivated, we compared the agronomic performance of 11-year-old ‘Tahiti’ lime trees grafted onto Carrizo citrange, Swingle citrumelo and Volkamerian and Rough lemons, planted with 4 x 6 m spacing, in a thin, strongly acidic (pH 4.5) clay soil. Tree dimensions, yield, production efficiency and fruit quality of eight harvests, from June 2008 to July 2009, were recorded. The most important results were: Carrizo, Swingle and Volkamerian induced lower height and canopy volume than Rough lemon, but the canopy formation of ‘Tahiti’ lime was wider than high, with all of them, b) fruit yield per tree was higher with Rough, but its production efficiency equaled that obtained with Carrizo and Swingle, c) Carrizo, Rough and Swingle induced a higher volume of export- grade (United States) ‘Tahiti’ lime fruit, with no differences among them in terms of the commercial sizes of the fruit produced, and d) the agronomic performance of Carrizo and Swingle, in terms of vigor, tree size, production efficiency, fruit quality and tolerance to termites, offers greater advantages for growing ‘Tahiti’ lime in savanna soils.

In order to study the effect of low temperatures on postharvest quality of basil (Occimum basilicum L.), grown with and without mulching, under modified atmosphere, its behavior was quantified in storage at 0, 5, 7 and 20 °C, for 16 days using a completely randomized design with three replications. The experiment unit consisted of a 30 g herbal bundle. Total soluble solids, titratable acidity, hydrogen potential, chlorophylls, carotenoids, ammonium content, color, fresh weight loss were evaluated. A hedonic evaluation was carried out, taking into account the following elements: visual appearance, turgidity, trade dress, decay and yellowing. Temperatures provoked different effects on postharvest quality. Basil suffered chilling injury at 0 °C. However, postharvest life of basil increased and its physicochemical charac- teristics remained similar at 5 °C. Postharvest quality was not affected by the use of mulching.

The effects of dry handling and the use of hydration solution (HydraflorTM) on the postharvest quality of cut flowers of four rose cultivars (Freedom, Opera, Red alfa and Red vicer) were assessed. After treatment, the stems were stored at 4 °C and 90 % relative humidity for 10 and 20 days, after which they were placed in a vase containing tap water or Crystal ClearTM preservative solution and then evaluated for fresh weight, flower opening, water uptake and vase life. The results show that vase life increases in dry-handled stems compared with those treated with HydraflorTM. The storage period significantly affected flower opening, which fell by 17.2 % with the change from 10 to 20 days of storage. Finally, dry handling is recommended for the rose stems of the cultivars evaluated, as it reduces costs and maintains the end quality of the flower.

Husk tomato is a fruit vegetable that is currently not grown intensively in greenhouse conditions due to the lack of an appropriate technol- ogy package. However, previous greenhouse experience has shown that, in free growth, fruit production is low and vegetative develop- ment is high. Assuming that a handling scheme based on pruning and population densities can increase yield, this experiment was carried out to generate a production system for husk tomato grown hydroponically under greenhouse conditions. The effect on crop production of three pruning variants (fourth internode, sixth internode and without pruning) and three population densities (5, 10 and 18 plants·m-2) was studied in three husk tomato varieties (Population 3, Tamazula SM2 and Tecámac Population) grown hydroponically under greenhouses conditions, in order to generate information regarding crop handling in a protected environment. The experiment took place during the 2004 summer-autumn cycle in the Experimental Field at the Universidad Autónoma Chapingo in Chapingo, Mexico, with a randomized block design with four replications under a split-plot arrangement. The highest yield per plant and fruit size was obtained in the Tecámac Population. Pruning did not affect crop production, but as population density increased so did yield, so that 18 plants·m-2 gave the highest yield (1.06 kg·m-2).

The aim of this work was to observe the influence of calyx on husk tomato postharvest life under different storage temperatures (4 and 20 °C) with or without calyx. The experimental design was a completely randomized design with 2 x 2 factorial experiment. Respiration rate, ethylene production, titratable acidity, loss weight, total soluble solids, vitamin C, firmness, color and chlorophyll content were determined. Treatments with calyx had higher total chlorophyll content with values ranging from 0.147 to 0.161 μg·100 g, at 0 and 20 days after har- vest, maintaining brightness, chromaticity and hue without significant changes. Fruits stored at 4 °C maintained (P ≤ 0.05) the behavior of firmness and soluble solids; in addition, fruits stored at 20 °C showed 5 % weight loss. Also, chlorophyll content was higher with values of 0.142 and 0.158 μg·100 g, this coincides with that observed in the color components. Changes manifested in firmness, weight loss, chlorophyll content and color were more related to storage temperatures, than to the presence or absence of calyx.

Over the last 30 years, plant extracts have been used against several phytophagous insect species, gaining importance as alternatives for pest control, because they do not affect the environment and are friendly to phytophagous insects’ natural enemies. In the present work, the insecticidal and repellent effects of C. chinense extract against B. tabaci adults were appraised. Repellency and mortality bioassays were performed using a flask (150 mm) with different concentrations of capsaicinoids extracted from habanero peppers (Capsicum chi- nense), local orange variety. A random experimental design was used with an 8 X 7 factorial arrangement for the mortality bioassay, and an 8 x 8 factorial arrangement for the repellency effect, with four replications per treatment. Concentrations of 30 and 40 % of the extract showed a higher mortality effect than others. Concerning the repellency, treatments >30 % of extract showed a higher repellency com- pared to other treatments. The results showed that C. chinense has a repellent effect during the first hour of exposure against B. tabaci.

Mamey sapote fruits harvested at physiological maturity were stored in 35 L containers and ethephon (2-chloroethyl phosphonic acid) was applied at 0, 100 and 500 mg·L-1 doses during 24 h. After this treatment, the fruits were stored during 0, 7, 14, 21 and 28 days at 10°C and then they were transferred at room temperature (24 ± 1°C, 50-60 % RH) during another eight days. The fruit ripening treated with or without ethephon was homogeneous. The quality characteristics were not adversely affected by ethephon use. After 14 storage days at 10°C ± 1 and eight days at room temperature the chilling injury symptoms started to show, and they were mild to severe after 21 and 28 storage days at the same temperature. The fruits stored during 21 and 28 days at 10± 1°C and ripened at room temperature, 24 ±1°C, showed chilling injury symptoms and increased presence of pathogens in the pulp, and lower total soluble solids content. Luminosity decreased significantly while the hue and chromaticity increased, the latter associated to chilling injury symptoms in the pulp (lignification and flesh browning). Respiration and ethylene production increased significantly after storage, even in the fruits where no ethephon was applied, suggesting that there was no significant response to exogenous ethylene on these parameters.

Tomato quality depends on its use and it is related to flavor, color, smell and nutraceutic properties and management processes. Re- searchers have improved these characteristics using wild relatives and native varieties. The ribbed tomato is grown and marketed in some regions of Mexico. These native varieties are characterized by the undetermined growth of the plants and their ribbed and very red fruits. The aim of this study was to determine the fruit production and quality of tree selections of tomato (Starmex1, Starmex2 and Starmex3) grown under greenhouse conditions using two osmotic potentials (OP) of Steiner ́s nutrient solution (-0.036 and -0.070 MPa), and using volcanic rocks (tezontle) as substrate. A total of six treatments and an experimental design of randomized complete block with ten replica- tions were carried out. Yield increased with the Steiner Solution at OP of -0.072 MPa in the selection Starmex2. The equatorial diameter in Starmex2 and the number of sepals in Starmex3 increased with the most concentrated solution regarding the morphology of the fruit. The pH increased only when plants were irrigated with nutrient solution at OP of -0.072 MPa, in the case of fruit quality.

To determine the potential of the nematode Heterorhabditis indica in the management of the white grub complex (Col: Melolonthidae), during 2010 and 2011 bioassays were implemented with larvae and adults of the pest in Jiquilpan, Michoacán, Mexico. The insects were collected in the study region; the first, in corn, and the latter, in light traps, where the genus Phyllophaga dominated. A dose of 2,500 nematodes·ml-1 per individual was applied and the mortality readings began at 24 h. To determine mortality, an analysis of variance was employed. The time in which 50 % of the population died (LT50) was estimated by means of probit analysis. The infectivity of the nema- tode was estimated through larvae of Galleria mellonella in three regional soils. In addition, correlation tests were practiced to know the relationship between the soil characteristics and mortality. Five days later, the mortality of third stage larvae was 46 %. For adults, the LT50 was estimated at 48.97 h (47-49 – 51.34 h). No infective juveniles emerged from any of the adults killed by H. indica. The texture, pH and EC were the soil characteristics that influenced most in the activity of the nematode. Results show that H. indica has potential for the management of larvae and adults of Phyllophaga spp. The technique of self-dissemination of the nematode is proposed using adults of white grub. However, first it is necessary to identify the cause that limited the emergence of juvenile nematodes from adults of the pest.

The color of the calyxes of Roselle (Hibiscus sabdariffa L.) is a quality parameter that is considered by consumers and it is related with the concentration of some phytochemicals. There is not information on the relationship between this parameter and some physicochemical characteristics of the aqueous extracts in Hibiscus varieties grown in Mexico. The aim of the present work was to determine the color of calyxes of eight different Roselle varieties and to establish the relationship with chemical parameters of the aqueous extracts. The color of the calyxes (whole and ground) and the extracts was measured with a Hunter-Lab colorimeter. Total anthocyanin content (ANT), ascorbic acid (AA), titratable acidity, pH and °Brix were determined. The color of the calyxes and extracts was related to anthocyanin and AA con- tents. Varieties with dark red calyxes contained five to seven times higher ANT content than varieties with light red calyxes. The variety with white calyxes had the highest AA content. In the case of color parameters, ground calyx brightness could be used to estimate ANT content due to the high and negative correlation observed between these two variables.