Seed treatments for control of Meloidogyne graminicola in flooded rice

Abstract

Meloidogyne graminicola is responsible for large yield losses in flooded rice, a problem that is mainly associated with the limited efficacy of nematode management tactics. This study aimed to assess the efficiency of different products applied by seed treatment in controlling M. graminicola in flooded rice grown from polymer-coated and uncoated seeds. Greenhouse experiments were designed to investigate treatment effects on nematode reproduction, root penetration, and plant vegetative parameters, and in vitro assays were used to assess treatment effects on egg hatching and juvenile mortality. Treatments were as follows: Wollastonite (calcium silicate), Agrosilicon (calcium and magnesium silicate), NemOut™ (Bacillus licheniformis\u2009+\u2009Bacillus subtilis\u2009+\u2009Trichoderma longibrachiatum), CompostAid® (Lactobacillus plantarum\u2009+\u2009B. subtilis\u2009+\u2009Enterococcus faecium), NemaControl®\u2009+\u2009StimuControl® (Bacillus amyloliquefaciens\u2009+\u2009Trichoderma harzianum), Nim-I-Go® (Azadirachta indica oil), Avicta 500 FS (abamectin), and CropStar® (thiodicarb + imidacloprid). Inoculated and uninoculated controls were also included. Avicta 500 FS, CropStar®, NemOut™, and CompostAid® were the most effective in reducing nematode penetration and number of nematodes per gram of root. The best in vitro results were obtained with Avicta 500 FS, CropStar®, NemOut™, and CompostAid®. Only Wollastonite showed no in vitro nematicidal activity. Most treatments also improved vegetative growth. It was concluded that treatment of rice seeds with chemical or biological products is effective in controlling M. graminicola.