Developing Biocontrol Strategies for the Management of Set rot Disease of Sugarcane under Wider Row Planting

Abstract

Sugarcane (Saccharum officinarum L.) is one of the economically valuable agricultural crops grown worldwide in tropical and subtropical areas mainly for their sugar source. Among the 110 sugarcane cultivated countries, India and Brazil contribute half of global production [1]. During the period of last five decades the production, productivity and sugarcane recovery has also shown remarkable resilience in productivity growth rate. One of the reasons for the low productivity and recovery is increasing incidence of insect pests and diseases. An ecologically friendly alternative to these problems is biological control using rhizobacteria and their metabolic products [2]. In order to develop a technology capsule Surveys and surveillance were conducted in sugarcane fields both in plant and ratoon crops distributed in Orthanadu and Vallam block in New Cauvery delta area of Thanjavur dictrict during three consecutive years 2019- 22 with an objective to assess the incidence of sett rot, red rot and smut in New Cauvery delta area of Thanjavur dictrict.  Fortnightly fixed plot observation was taken.  The Maximium and minimum temperature, RH and quantity of rain and rainy days also recorded daily and consolidated on monthly basis and weather parameters were correlated with the incidence of disease. The results revealed that the maximum incidence sett rot negatively correlated with temperature. Similarly the number of rainy days and rainfall is positively correlated (r = 0.7523) with incidence of sett rot. For managing sett rot disease of sugarcane through biological approach, studies were conducted on biocontrol agents viz., Trichoderma asperellum (TNAU), Bacillus subtilis (TNAU), Chaetomium globosum (Cg6) with fungicide check propiconozole 0.1%. Among the treatment, highest millable cane (91,080/ha) and yield (91.39 tonnes / ha) and sugar yield ( 10.63 tonnes/ha) were recorded in M1- (Single bud treated with Trichoderma asperellum (TNAU)@ 4 g l-1 + soil application @ 2.5 kg  ha-1) followed by M2-  (Single bud treated with Bacillus subtilis (TNAU)@ 10 g l-1 + soil application @ 2.5 kg ha-1) in which, the cane yield of 88.54 tonnes/ha and sugar yield of 10.68 tonnes/ha were recorded. This study provides a technology capsule for the management of important disease of sugarcane.