Anthocyanins are a group of plant metabolites responsible for the red pigmentation in calyx of roselle (Hybiscus sabdariffa L.. The plant tissue culture has been used for the production of secondary metabolites; however, the potential of plant cell cultures for the production of anthocyanins is still limited. In the present study, an evaluation was made of different inducers of plant growth regulators such as: na¬phthaleneacetic acid, 2,4-dichlorophenoxyacetic acid, kinetin and salicylic acid, methyl jasmonate, nitrogen deficiency and osmotic stress to stimulate the production of anthocyanins and phenolic compounds in callus and suspension cells in vitro of three varieties of rosette (China, Reyna and White). The highest content of phenolic compounds in callus was obtained from the variety Reyna with 670 mg of gallic acid equivalents•100 g-1 dry weight under osmotic stress conditions. It induced the production of anthocyanins in callus of the varie¬ties China and Reyna (94 and 161 μg∙g-1 fresh weight, respectively) established on MS medium supplemented with 7.5 mM of inorganic nitrogen. Using a RT-PCR analysis in the calluses that showed production of anthocyanin, the transcriptional expression was shown of genes coding for anthocyanin and flavones synthase 3´-hydroxylase, suggesting that the nitrogen source regulates the final steps in the biosynthetic pathway of anthocyanins in cell cultures of roselle in vitro.

Eight commercial hybrids of summer squahs type ‘Grey Zucchini’ (Cucurbita pepo L.) and their 56 possible crosses of a diallel using the Method I Model II of Griffing (1956) were evaluated in Chapingo Mexico, during 2007 and 2008; to identify the best combinations among the commercial hybrids according to the general combining ability (ACG) and specific combining ability (ACE) effects; and to begin a genetic improvement program to get squash synthetic varieties. The experimental design used was a randomized complete block with three replications. The experimental plot consisted in two rows of 5 meters, with row separation of 0.80 m and 0.2 m between plants (62,500 plants•ha-1). The combined analysis showed that dominance effects for the main components of the yield: fruit per plant, yield per plant and hectare were more important, and number of days to female flowering additive effects were important and make it feasible to improve precocity. From the best six crosses for squash fruit yield, three of them could only be used as hybrids (ACG < ACE): Hurakan x Lolita (52.16 t•ha-1); Lolita x Tala (50.14 t•ha-1); Tala x Terminator (47.72 t•ha-1); two as synthetic varieties (ACG > ACE): WA9041 x Lolita (51.45 t•ha-1); Grey Zucchini M+M x Terminator (50.00 t•ha-1) and one as a base population to be improved by recurrent selection, since the additive and of dominance effects are important (ACG = ACE): Lolita x Terminator (44.09 t•ha-1).

The use of liquid manure as a source of nutrients and water in agricultural production decreases environmental pollution and leads to economic savings for farmers. We compared the use of liquid cattle manure extract (LCME) and chemical fertilizer in nutrient solution, plus their respective water use efficiency index, in tomato (Licopersicon esculentum Mill) production in a hydroponic greenhouse system. Three factors were assessed at two levels: raw and fermented LCME; electrical conductivity (EC) of two solutions (2 and 4 dS∙m-1); and the addition of chemical fertilizers to supplement the LCME solutions. Two treatments with inorganic fertilizers (Steiner’s solution) were added to each EC level as controls. A total of ten treatments were evaluated in a factorial arrangement (23) with eight replications. Results showed higher dry matter (133.9 g∙plant-1) and yield (2,742 g∙plant-1) values in plants irrigated with nutrient solutions with EC of 2 dS∙m-1. The fermented and fertilizer-supplemented LCME solutions had the same behavior as the raw LCME without fertilizers in tomato plant growth and yield in a hydroponic greenhouse system.

The objective of the present work was to determine the effect of Controlled Atmosphere (CA) storage on the postharvest quality and nutritional content of tomato (Solanum lycopersicum L.) ‘Imperial’. Mature green fruit were stored at 12 °C under refrigeration (ambient air, AIR) or CA (4 kPa O2 + 96 kPa N2) at 12 °C for up to 21 days before being transferred to air at 23 °C for up to 12 days. Three fruits were taken per treatment after zero, four, eight and 12 days of ripening at 23 °C to evaluate external color, firmness, soluble solids content (SSC), CO2 and ethylene production rates, and ascorbic acid, β-carotene and lycopene content. CA storage delayed the loss of firmness and ascorbic acid degradation. It also decreased CO2 and ethylene production rate, β-carotene and lycopene synthesis, delaying red color development and ripening. The results indicate that storage of tomato fruit under CA extends the shelf life and the marketing period compared with traditional refrigeration systems.

In order to grow ornamental plants in non-controlled environments, the effect of temperature on seedling emergence and growth must be known in order to optimize plant production. The aim of this research was to compare the growth of statice and viola seedlings, dur¬ing the winter in the Valley of Mexico, under three production conditions: a polyethylene-covered tunnel, shade netting that cuts light transmission by 50 %, and in the open. We measured air temperature (0C), emergence percentage (E%), leaf area (LA) per plant and dry weight biomass (DWB) per plant at 10, 18, 24, 31 and 35 days after planting (dap) in statice seedlings, and at 21, 28, 35, 43 and 52 dap in viola seedlings. In addition, the absolute growth rate (AGR), the relative growth rate (RGR) and the net assimilation rate (NAR) were calculated. Compared to the outdoor treatment (control), The polyethylene tunnel and shade netting produced higher E% values: 95 and 93 % for statice and 97 and 95 % for viola, respectively. Two different sigmoid curves of dry matter accumulation were observed in both species. The polythene tunnel produced higher DWB than the other conditions (P≤0.05) with an average temperature of 19.5 0C and high thermal oscillation, but without frost. In the polyethylene tunnel, maximum DWB, LA and AGR (88 mg∙seedling 1, 15.1 cm2∙seedling 1, and 7.4 mg∙d-1, respectively) were observed at 35 dap in statice and 52 dap in viola (43.6 mg∙seedling 1, 7.6 cm2∙seedling 1 and 2.4 mg∙d-1, respectively) before transplanting. The polythene cover prevented temperatures below 0 0C, which explains the greater seedling growth in this environment.

Thyme (Thymus vulgaris L.) is an aromatic plant, whose consumption is increasing at rates that are two or three times the world’s popula¬tion growth, which is generated for the essential oil use in food, cosmetic and pharmaceutical industries. Under this perspective and with the need for obtaining higher yields of essential oil than those obtained in open fields, the aim of the present work is to evaluate both essential oil quality and yield of thyme cultivated in a greenhouse under an open hydroponic system. Three growing densities were evalu¬ated: D1, D2 and D3 (14, 28 and 71 plants•m⁻², respectively) and two concentrations of the Steiner nutrient solution (S1: 100 % and S2: 50 %). A 3x2 factorial experiment with four replicates was used for each treatment. The results show that higher values for plant height were presented with S1 D2, and S2 D1, for the stem diameter with S1 D2 and S1 D3; no statistical difference was presented among the treatments for fresh and dry weight, although the largest number of leaves was presented with S1 D2 and S2 D1; the largest area leaf was only reached with S1 D2. In the analysis of the oils four components were identified (p-cymene, α-terpinene, carvacrol and thymol) of which the most abundant was thymol with 23.331 %. The use of hydroponic crops allows cultivation of high sowing density species and to obtain a high quality product, recommending S1 D2 as the best treatment where thyme ideal growth is obtained in all the variables.

Pests and diseases represent a problem in ornamental crops, which at the same time affect the international trade and therefore have to be controlled. The main markets for cut flowers are located in Europe, United States and Japan. Mexico is one of the main suppliers to USA. Roses are currently the most important ornamental crops and also they are very susceptible to diseases, which spread easily. It would be possible to conduct early protection and treatment applications if diseases could be detected on early stage as well as the causal agents. In this research a detection system of powdery mildew(Sphaerotheca pannosa)on rose was developed with Open CV. Open CV is an open source computer vision library, which is written in C and C++ language. The detection was made according to the HSV space color. The source image was converted from the RGB to the HSV space color and the disease and the plant parts were extracted according to the H, S and V information. After that the noise (white objects) was removed. Finally the accuracy of the detection was evaluated. The developed disease detection system is able to detect the powdery mildew disease through the HSV space color with Open CV. Better results were obtained when using close pictures (10 cm). The miss-matched rate caused mostly by halation when using distant pictures could be successfully avoided using active sensing which allows for disease detection even when using distant pictures.

Greenhouse production of fruits and vegetables in Mexico has increased from 721 ha in 1996 to 9,500 ha in 2009. A fungal disease caused by Fusarium stilboides has recently appeared in pepper (Capsicum annum L.) that affects the fruit peduncle in the postharvest period. An alternative means of reducing the damage caused by this fungus is the use of biological control methods. To assess the antagonistic capacity of yeast strains of different origin to control F. stilboides and compare them with chemical methods, pepper fruits were inoculated with a known yeast suspension (107 CFU•mL-1) and a spore suspension of F. stilboides (105 CFU•mL-1), or they were immersed in different fungicidal solutions (benomyl, captan, sodium bicarbonate and potassium bicarbonate) at various concentrations and then inoculated with the fungal spore suspension. Benomyl at 0.6 g.L-1 showed the highest severity-inhibition level on the peduncle (81 %), while sodium bicarbonate at 30 g.L-1 was the most effective on the epicarp (51 % reduction in lesion diameter). Yeasts-25b and 18-1x from apple, Avv, 5vtt (Candida incommunis) from wine veils and 3d. RMA3 from pepper reduced lesion diameter on the epicarp by 63, 54, 53, 47 and 45 % respectively.

Three growth inhibitors (cycocel, uniconazole and paclobutrazol) applied at different concentrations were assessed to determine their ability to produce compact potato (Solanum tuberosum L.) plants with reduced leaf area, but without reduced tuber yield, in an experiment conducted in hydroponic greenhouse conditions. The treatments were: paclobutrazol (50, 100, 150, 200 and 250 mg.L-1), uniconazole (2.5, 5, 10, 20 and 40 mg.L-1), cycocel (200, 400, 800, 1,600 and 2,400 mg.L-1) and a control without regulators, with 10 pots as the experimental unit. A randomized complete block design with 16 treatments and four replications was used. Uniconazole and paclobutrazol were more effective in reducing growth, leaf area and leaf area index compared with cycocel. Uniconazole at concentrations >5 mg.L-1 reduced plant height (23 and 46 %), tuber biomass and total plant biomass compared with the control. Paclobutrazol applications at 100, 200 and 250 mg.L-1 reduced plant height (50 to 64 %), tuber biomass (44 to 69 %) and total plant biomass (45 to 67 %); at 150 mg.L-1, it reduced plant height (42 %) without affecting tuber biomass (47.0 g). Uniconazole at 20 mg.L-1 and paclobutrazol at 150 mg.L-1 produced stunted potato plants and reduced their leaf area index from 13.9 in plants without inhibitors (the control) to 10.93 and 9.34, respectively, without affecting the number of tubers per plant, tuber biomass or harvest index.

The extended harvest season of ‘Hass’ avocado is due to the diversity of cultivation conditions and the occurrence of multiple vegetative flushes resulting in several bloom and harvest periods. The objective of this study was to evaluate the influence of three climatic condi¬tions (subhumid semiwarm, humid semiwarm, and subhumid temperate), soil moisture regimes (with and without irrigation), and flowering period (“crazy”: August-September; “normal”: December-February; “marceña”: February-March), on biomass of different fruit parts and their nutrient composition. Six trees were selected from each of the six commercial orchards, choosing ten fruit of each tree per flowering season (≥21.5 % pulp dry matter). Fruits were separated in epidermis, pulp, testa, and embryo. Fresh weight (FW), dry weight (DW), dry matter (DM), and nutrient composition were determined for each part. Different to climate and soil moisture regimes, flowering period affected FW, DW, and DM of the fruit parts, as well as their nutrient composition, especially, K, Ca, Mg, S, Fe, Cu, Mn, Zn, and B. Under subhumid climate, the highest contents of N and Mn were obtained in epidermis; of N, P, K, Ca, and Mg in pulp; of Mg, S, Cu, and Mn in testa; and B in testa and embryo. Non-irrigated orchards had higher concentrations of Ca, S, and Cu in epidermis; P, K, Mn, Ca, and Cu in pulp; K, Mn, Cu in testa; and P, K, Mn in embryo.