Efeito do fluxo de água, estímulo vegetal e volume de poros do solo na mobilidade de Pratylenchus coffeae

Abstract

The plant-parasitic nematodes are among of the main plant diseases inducers causing serious damage to the crops. The control of these parasites is a challenging and complex task. Because the distribution approach of nematodes in field and the high influence of water movement on parasite transport in soil, researches simulating the nematode movement in soil have been strongly encouraged. In this study the effect on the lesion nematode Pratylenchus coffeae movement of water flux (5 ml min-1), soil pore volume (PV) and baits of Tagetes patula root pieces and yam (Dioscorea cayennensis) root barks was evaluated in deformed soil columns. The juveniles and adults mobility was monitored in acrylic resin columns, filled with washed sand, with one of the extremity exposed to one of the baits. In soil with no water flux P. coffeae mobility was affected by any variable five days after nematode infestation, in soil with water flux nematode mobility and direction was significantly (P<0.01) affected by the bait and soil PV. The nematode leaching gradually increased from 1.4 PV. In general, most nematodes were leached to the extremity opposite to the bait through the water flux (negative way), despite columns with T. patula root pieces presented higher nematode leaching. In contrast, in columns with yam root barks some of the nematodes endure to the water flux remaining in the water injection site close to the root barks.