Compatibility of Trichoderma spp. with copper-chitosan graded combinations

摘要

A total of 22 Trichoderma isolates were evaluated for their compatibility with dual combinations of copper hydroxide and chitosan (ChoF: liquid formulation) under in vitro conditions to check their maximum tolerance limit. The Trichoderma isolates were screened at graded (250+250, 500+500, 1000+1000 and 2000+2000 ppm) combinations of copper hydroxide and chitosan. Only six isolates viz., TCMS-36, TCMS-60, TCMS-62, TCMS-65, SBIT-32 and SHI 1-76 found compatible with exhibiting hundred per cent growthat 500 ppm (each) combination of copper hydroxide and chitosan. At 1000 ppm (each) combination only six isolates were found partially tolerant and none of the isolates was found completely tolerant. Maximum growth was observed in SBIT- 32 and TCMS-14b (3.6 cm), followed by TCMS-60 (3.5 cm), Th-1 with 2.9 cm colony diameter. Further, at 2000 ppm (each) combination, none of the isolates showed growth. Results indicated that optimum dose of copper and chitosan to use in combination with Trichoderma was 250and 500 ppm (each). Hence, while using the triple combination of copper hydroxide (fungicide), chitosan (plant defense inducer) and Trichoderma spp. (biocontrol agent) for management of crop diseases, the optimum dose of the copper and chitosan may be selected as 250-500 ppm.