Management of Radopholus similis and Helicotylenchus multicinctus in Ratoon Banana Grown under High Density Planting Systems

Cultivation of banana in modified high density planting systems with more crop cycles is widely followed in Gujarath, Kerala, and Tamil Nadu states of India due to its higher productivity and lower cost of production. In this system, three suckers were planted in a pit spaced at 1.8 × 3.6 m accommodating 1542 mats or 4626 plants/ha. Nematode pests remain a threat to this modified system of banana cultivation especially in ratoon cycles. Investigations were undertaken in ratoon banana grown under a high density planting system on effect of cartap hydrochloride 4G, carbofuran 3G, Glomus mosseae, Pseudomonas fluorescens, Sunhemp, Coriander, Marigold, and neem cake on control mixed populations of burrowing nematode, Radopholus similis, and spiral nematode, Helicotylenchus multicinctus. Application of cartap hydrochloride @ 20 g/mat twice at the time of ratooning followed by 4 months later gave greater control of R. similis and H. multicinctus in soil and root with lesser damage in root and corm than untreated plants. The banana plants in this treatment were taller with a larger number of leaves and thicker pseudostem girth resulting in 33.4-37.3% more bunch yield than other treatments including control. The effect of cartap hydrochloride at 20 g/mat was similar at higher dose (40 g/mat) but significantly superior than 10 g/mat dose. Carbofuran 3 G @ 80 g/mat twice, Neem cake @ 250 g/mat twice and growing Marigold around the basin and incorporating before flowering were the next best treatments on nematode control and growth promotion. The P. fluorescens and G. mosseae applied were not established well and caused lesser nematode control in ratoon banana grown under high density planting system. Hence application of cartap hydrochloride @ 20 g/mat or neem cake @ 250 g/mat or growing Marigold around the basin and incorporating before flowering could rectify the damage caused by R. similis and H. multicinctus in ratoon banana crops growing under a high density planting system.