Suppression Effects on Pineapple Soil-Borne Pathogens by Crotalaria juncea,Dolomitic Lime and Plastic Mulch Cover on MD-2 Hybrid Cultivar

The development and implementation of sustainable and environmentally friendly agricultural practices are indispensable as alternatives to pesticide use and to keep populations of soil-borne plant pathogens at levels that do not affect crop productivity.The present research evaluates the incidence of soil-borne phytopathogens on the pineapple variety MD-2,which was subjected to different treatments:Incorporation of Crotalaria juncea into the soil(organic amendment),application of dolomitic lime to soil(inorganic amendment),and the use of plastic mulch covering the soil.During the crop cycle(15 months),the following variables were evaluated:plant height(cm),fruit weight(kg·plant^(−1)),crop yield(ton·ha^(−1)),the bud root disease incidence caused by Phytophthora nicotianae,number of soil phytoparasitic nematodes and colony-forming-units(CFUs)of soil fungi and oomycetes.The results indicate that Crotalaria juncea treatment reduced the pathogen population(nematode and oomycetes)at levels that did not affect crop development,so that yield increased(18–20%).The incorporation of C.juncea into the soil as an organic amendment favors the populations of fungi disease suppressors(Trichoderma-Aspergillus).The phytoparasitic nematodes(Meloidogyne sp.,Pratylenchus sp.,and Mesocriconema sp.)and oomycetes(Phytophthora spp.,and Pythium spp.)showed a reduction of their population levels by effects of organic amendment(C.juncea).The plastic mulch was also effective,probably due to the maintenance of optimal condition to crop growth and weed control.However,the dolomitic lime application had the poorest effect under the conditions of the study area on the variables analyzed.The described observations are characteristics of a system-based approach for the potential management of soil-borne pathogens of pineapple MD-2 in Veracruz,México.

Effect of Kelp Residue Microbial Fertilizer on Eco-Control Peanut Pathogenic Fungus Aspergillus Parasiticus 1

Ecological prevention and control of plant disease is very important in sustainable agriculture.Adjusting soil p H value and fertilizing organic microbial fertilizer are two effective measures in this process.Kelp residue contains a large amount of organic compounds and alkaline metal ions.The bio-control Bacillus amyloliquefaciens strain Hitwh-BA2 was inoculated into kelp residue medium to produce kelp residue microbial fertilizer.Acidic soil and alkaline soil were used to study the effect of kelp residue microbial fertilizer on soil p H and soil suppressive activity.Tip-culture method was used to determine soil leachate suppressive activity,which characterized the soil suppressive activity.Results showed that fertilizing kelp residue microbial fertilizer had increased the soil p H and soil suppressive ability significantly,which was verified by peanut validation experiments as well.Peanut potting experiments proved that fertilizing kelp residue microbial fertilizer not only improved the yield of peanuts obviously,but also reduced the amount of Aspergillus parasiticus 95 in peanut geocarposphere soil significantly.Results also showed that fertilizing kelp residue microbial fertilizer was effective in reducing A.parasiticus 95 infection rate.So the kelp residue microbial fertilizer has good potential application prospect on ecological prevention and control of plant disease.