Amelioration and/or reclamation of saline and non-saline soils is based on the application of high quantities of agrochemical products or high volumes of water, which causes an injury in soil or downward displacement of nutrients to the lower layers in soils. Research was conducted to evaluate the effect of application of citric industry waste on saline and non-saline soil. The waste has an electrical conductivity (EC) of 2.7 dS/m and pH of 3–4.2, 35% is organic material that is readily decomposed. This experiment was carried out on field conditions using applications of three different volumes, T1 = 3200, T2 = 6400, and T3 = 9600 m3·ha–1·m–1 and a control, no-waste, (T0), using just irrigation water (EC = 2.5 dS·m–1). The same treatments were added to non-saline soil. Effect of citric industry waste application in both saline and non-saline soils was similar. In all the treatments, EC was decreased with respect to T0 and soil before application (BA), the largest decrease was found in T3. pH decreased in the top soil layer much more than in the bottom layers. Ions were decreased in all soil profile. Organic matter (OM) was increased in the profile in treatment T1 with respect to treatment T0, as well as in the top soil layers in T2 and T3, but no changes were detected in the remainder of the layers in treatments T2 and T3. We can suggest that the waste studied can be used in the amelioration of saline and non-saline soils.
J.G. Lopez-Aguirre, J. Molina-Ochoa, J. Farias-Larios, S. Guzman-Gonzalez, and A. Michel-Rosales
Mario Orozco-Santos, Javier Farias-Larios, J. Gerardo López-Aguirre*, Emilio Sánchez-Arévalo, and Jaime Molina-Ochoa
In Central Pacific region, Mexico, are cultivated around 17,000 ha of cucurbitaceous. This crops are affected by wilt, this disease is caused by Fusarium oxysporum (F.o.) Schlechtend. Some farmers are using resistant varieties to this disease, but resistance is different to each cultivar. Soil fumigation is other way to control this pathogen. Soil solarization is a new alternative for Fusarium oxysporum control. The objective of this research was to evaluate the effect of soil solarization on Fusarium oxysporum for wilt control in muskmelon crop in Colima State. The experiment was carried out under field conditions, using Cantaloupe melon (Cucumis melo L.) Cv. Ovation, in Ixtla-huacán municipality during November-December. Clear plastic was used (thickness 110). Evaluation of solarization periods were 0, 10, 20, and 30 days. Experimental design was full random blocks, with four replications. Evaluated variables were: soil temperature at 5-,10-, and 20-cm soil depth, propagule number of Fusarium oxysporum in soil, wilt incidence and yield. For determine Fusarium oxysporum survival, a strain isolated from infected plants was used. Fungi was introduced in cloth bags, containing 10 gr of sterile sand with 10 mL of a suspension of 19,000 conidia/mL. Later were introduced four cloth bags per treatment at 5-,10-, and 20-cm soil depth. When plants were harvested, was taken the sick plants percentage. Results shown that soil solarization periods had not an effect on the propagule number at the soil depth for the solarization periods. Also soil solarization had not and effect on plant yield. Is necessary to do the same experiment during different season, as June-July or September-October, to have a higher soil temperature and humidity.
R. Lezama-Gutierrez, J. Molina-Ochoa, O. Rebolledo-Dominguez, M. Gonzalez Ramirez, and M. Lopez-Edwards
Virulence of several isolates of the entomopathogenic fungi Beauveria bassiana (Bals.) Vuill., Metarhizium anisopliae (Metsch.) Sor. and Paecilomyces fumosoroseus (Wize) Brown & Smith were evaluated on adult weevils of Anthonomus fulvipes Boheman at dose of 108 spores/mL under laboratory conditions. The study was complemented by testing one isolate each of M. anisopliae and P. fumosoroseus against adult weevils on organically grown Barbados cherry trees at dose of 2 × 1015 spores/ha. All fungi species showed high virulence against A. fulvipes adults, with mortality ranging from 92% to 100%. LT50 values varied 2.7 to 4.8 d. The M. anisopliae isolate 10, and the P. fumosoroseus isolate 1 were selected for field evaluation because laboratory insect cadavers presented the best sporulation. After applying the fungi to the trees, total weevil captures were 38, 56, and 100 for the P. fumosoroseus, M. anisopliae, and the check (untreated) plots, respectively. Statistical differences in fruit damage were detected among treatments: M. anisopliae and P. fumosoroseus treatments showed an average of 50% of undamaged fruits, whereas in the control plots presented 36% of undamaged fruits. Laboratory and field experiments suggest that entomopathogenic fungi have a potential as microbial control agents against the weevil A. fulvipes in organically grown Barbados cherry trees.