Effect of Insecticides on Bio-Agent Trichoderma harzianum rifai Under In vitro Condition

Abstract

Potential bio-agent Trichoderma spp. is used to control soil borne plant diseases. Mode of actions of Trichoderama is antibiosis, parasitism and competition. Even though, Commercial formulations of Trichoderma are not working properly because of malpractices implemented in the fields. Over usage of chemical pesticides affects the growth and efficacy of bio agent Trichoderma. Therefore, in-vitro study aimed to assess the compatibility of heavily spraying insecticides in Jaffna, Sri Lanka, with Trichoderma harzianum by using Poison food technique. Six insecticides, Admire (Imidachlorprid), Asie (Acephate 75% w/w), Mospilan (Acetamiprid 20% w/w SP), Actara 25 V.G (Thiamethoxam (25%) SP), Selecron (Profenofos 500g/L EC) and Coragen (Chlorantraniliprole) were evaluated at the recommended dose. Results revealed that three insecticides viz Chlorantraniliprole (85 mm MCD), Acetamiprid 20 % w/w (85 mm MCD) and Imidachloprid (85 mm MCD) compatible to growth of T. harzianum and higher inhibition percentage was measured against profenofos 500g/L EC as 59.29 % with 34.60 mm mean colony diameter. Thiamethoxam (25 %) SP and Acephate 75 % w/w SP were also inhibited as 03.82 % (81.75 mm MCD) and 02.41 % (82.95 mm MCD) respectively but, compare to profenofos, insignificant. Trichoderma is compatible to most of the chemicals therefore; commercial farmers can use it in the Integrated Disease management to safe guard the environment, reduce the human health hazards and also cut down the unwanted pesticide cost.