Strategies for managing of lesion nematode (Pratylenchus zeae) in sugarcane fields

Lesion nematodes cause significant yield losses in sugarcane, with global reductions ranging from 10 to 40%. Identifying effective bioagents for soil application is critical to improving sugarcane production. Misdiagnosing nematode infestations as nutrient deficiencies or soil toxicity can limit nutrient availability to plants, exacerbating the problem. To address the challenges posed by lesion nematodes in sugarcane, the present investigations was conducted in a farmer’s field under the sugarcane variety CoC 25 in Vriddhachalam, Cuddalore district, Tamil Nadu, India. The study evaluated the efficacy of talc-based fungal antagonists, including Trichoderma viride, T. asperellum, Purpureocillium lilacinum, T. harzianum, Pochonia chlamydosporia, T. reesei and Clonostachys frosea as well as bacterial antagonist such as Bacillus firmus, B. subtilis and Lysinibacillus fusiformis against lesion nematode Pratylenchus zeae. These biocontrol agents were applied at 2.5 kg/ha and compared with the standard recommendation of carbofuran applied at 33 kg/ha. All tested fungal and bacterial antagonists significantly reduced the soil population density of lesion nematode. In the first year, sett treatment experiments demonstrated that the application of the fungal antagonist P.lilacinum at 2.5 kg/ha reduced nematode populations by 74.3% compared to the untreated control. This treatment also improved germination (84.26%), tillers count (166.62%), commercial cane sugar percentage (12.80%), cane yield (120.50%) and sugar yield (16.82%). Similarly, the bacterial antagonist, Bacillus subtilis at 2.5 kg/ha reduced nematode populations by 71.3% and improved germination (85.22%), tillers count (165.32%), commercial cane sugar content (12.30%), cane yield (118.60%) and sugar yield (16.66%). In the second year, combining P. lilacinum at 2.5 kg/ha with Fluensulphone 2% GR at 10 kg/ha resulted in a reduction of lesion nematode populations by 81.23% and achieved a maximum cane yield of 118.3 t/ha. The application of P. lilacinum proved to be highly effective in reducing nematode populations and is recommended for inclusion in an integrated nematode management module.