Cultivar Resistance of Sugarcane and Effects of Heat Application on Nematodes in Kenya

Abstract

This study was carried out with the aim of screening selected sugarcane germplasm for their response to nematodes and evaluating the potential of soil heat treatment in the management of the nematodes. Seven sugarcane cultivars namely CO421, CO617, CO945, EAK70-97, KEN83-737, KEN82-808 and KEN82-216 were evaluated against N14 as the reference germplasm for resistance against plant-parasitic nematodes in the greenhouse. Data on nematode numbers, shoot and root weight was recorded at 0, 60 and 120 Days after Planting (DAP). Nematodes were extracted from the sugarcane rhizosphere using the Modified Baermann funnel technique. Sugarcane cultivar KEN83-737 was rated as highly resistant while moderately resistant cultivars included CO421, CO617, CO945, EAK70-97 and KEN82-216. Cultivar N14 was confirmed to be susceptible to nematodes. Nematodes from four genera namely Pratylenchus, Scutellonema, Helicotylenchus and Hoplolaimus were significantly responsive to the sugarcane cultivars. Among the nematodes associated with sugarcane, lesion nematodes (Pratylenchus sp.) were dominant in all the cultivars averaging 188/200 cm3 soil, while the lance nematode (Hoplolaimus sp.) had the lowest numbers (92/200 cm3 soil). Soil heat treatment resulted in increased sugarcane root biomass. In addition, heat treating the soil resulted in a 27 and 30% increase in sugarcane root and shoot lengths, respectively. Similarly, compared to the controls, 52 and 25% increase in root and shoot weights were recorded in sugarcane grown in heat treated soil, respectively. This study has shown that sugarcane cultivar resistance is a viable management strategy for nematod