Soil solarization is used for soil born pathogens control, as a result of temperature increase in soil, around 10 °C higher than in not solarized soils. In Mexico, is mostly used to decrease cost to control of different diseases that affect to melon crop, one of them is caused by Fusarium oxysporum f. sp. melonis (L & C) Snyder & Hansen, which is characterized by wilt and yellowing in melon plants. The objective of this assay was to evaluate the effect of heat on infective capacity of F. oxysporum f. sp. melonis in melon plants and its reproduction capacity after to be under different periods of heat under laboratory conditions. Isolated was taken from melon plants from Carmelitas Ranch in the Colima Municipality. Inoculation was 1 × 10-6 conidia concentration. Cloth bags, with 20 g of inoculated soil, were introduced at 9 cm depth in metallic pots (16 cm diameter and 18 cm depth) containing 4 kg of not inoculated soil during 24, 48, 72, 96, and 120 h, with 6 replications. After each period, 1 g was taken from the cloth bags used in heat treatments, later was diluted in 50 mL of distillated water, and petri dishes containing PDA, were inoculated with 1 mL from that dilution and inoculum viability was registered at 96 h after incubation. Parameters evaluated were: mycelium growth, propagule number, and conidia number. Results showed a positive effect to control of Fusarium oxysporum f. sp. melonis, in treatments with a higher heat period, respecting to the control. Is necessary to evaluate this technique under field conditions during summer season.
Roney Ballinas-Cano, Javie Farias-Larios, Mario Orozco-Santos, J. Gerardo López-Aguirre*, and Emilio Sánchez-Arevalo
Francisco Roman-García, María Patricia Yahuaca-Mendoza, Javier Farias-Larios, J. Gerardo López-Aguirre*, Sergio Aguilar-Espinosa, and María del Rocío Flores-Bello
The contribution of arbuscular endomycorrhizal fungus (AMF) on hormonal levels increase in chili plants, at different steps is currently unknown. In this experiment was evaluated the effect of Glomus sp. Zac-19, G. etunicatum and G. intraradices, inoculation mirasol and ancho cultivars, under greenhouse conditions. Plants were growing in pots containing 1 kg of substrate (3 sand: 1 soil ratio). The effect was measured on fresh fruit production and indolacetic acid, giberellin GA3 and 6-aminopurine concentration. Also plant parameters measured were: plant height, foliar area, stem diameter, root length, aerial fresh weight, total fresh weight, fruit weight and mycorrhizal colonization. All treatments were imposed using 16 replications in a full random design. Results shown that mycorrhizal colonization average of the three fungus was 44% in mirasol cultivar y 42% in ancho cultivar. Mycorrhizal colonization had an effect on growth and development in both cultivars, expressed in a greater height, leaf number, foliar area, total fresh weigh and fruit mass. Was registered an increase of 80% in the yield in inoculated plants respecting to control. Indolacetic acid and gibberellins concentration in shoots, were bigger in plants colonized by arbuscular mycorrhizal fungus (AMF) than in control. The 6-aminopurine levels in roots of colonized plants by AMF shown higher values. These results suggest that AM fungi modify the hormonal concentration and some growth factors in chili plants.