GREEN MANURE AND Pochonia chlamydosporia FOR Meloidogyne javanica CONTROL IN SOYBEAN1

Abstract

Pochonia chlamydosporia (Pc) is a nematophagous fungus with saprotrophic activity. However, little is known about the interaction between Pc and green manure. This study aimed to investigate the interaction effects of different green manures and Pc on the control of Meloidogyne javanica in soybean. Two greenhouse experiments were conducted in different periods using a 6 × 2 factorial design, with six replicates. The first factor was green manure application (oat, brachiaria, crotalaria, millet, buckwheat, and untreated control) and the second factor was treatment with Pc (in-furrow application and untreated control). Cover crops were grown separately and applied to pots as green manure 15 days before soybean sowing. At 5 days after sowing, soybean was inoculated with 2 000 eggs and juveniles of M. javanica. At 60 days after inoculation, nematode and vegetative variables were determined. All green manures reduced nematode population levels, especially oat, crotalaria, and buckwheat. Pc treatment did not influence nematode population levels. Soybean plants treated with oat or crotalaria green manure had greater height than untreated plants in both experiments. The effects of factors on shoot fresh and dry weights differed between experiments, and green manure application did not affect root development. The findings confirmed the potential of plant residues to control M. javanica.