Studies on eco-friendly management of false smut in basmati rice

Abstract

Rice (Oryza sativa L.) is a most important staple food grain crop for more than 3billion people around the world. Rice is the second most important cereal crop after wheat, which feed about 45% of world population. Cultivated rice is of two types i.e., aromatic and nonaromatic rice. India is largest producer and exporter of basmati rice in the world. Rice crop is affected by various biotic and abiotic stress. Biotic stress includes various kinds of ailments such as fungi, bacteria, virus & nematodes. Among them, false smut of rice becoming major point of concern nowadays. It is also known as pseudo-smut or green smut disease of rice. This disease occurs in all rice growing countries in the world. It affects the early flowering stage of the rice crop. The sustainable approach towards controlling disease can be use of bioagents. Trichoderma spp. are an effective bio control agent for the management of pathogens affecting various crops. The present study was conducted to test the efficacy of different bioagents and fungitoxicants against false smut of basmati rice under field condition and in-vitro. Seed treatment and seedling root dip with six strains of T.harzianum viz IRRI-1, SV-2, SV-3, SV-7, SV-14, SV-21 and two different formulation of P.flourescens viz., FYM based and fresh coconut water based were used for seed treatment and seedling root dip under field condition. T.harzianum IRRI-1 was most effective followed by T.harzianum SV-3 with least disease severity and also increase yield parameter of crop among the bioagents. Foliar spray of five different fungitoxicants at booting and flowering stage of crop was applied among them Propiconazole 25 EC was found best with least disease severity. The efficacy of same T.harzianum strains in-vitro was done by dual culture technique. Maximum percent mycelial growth inhibition was recorded with T.harzianum IRRI-1 and T.harzianum SV-3. Similarly, fungitoxicants were also evaluated invitro by poison food technique at 25 and 50ppm concentration. Among them, Propiconazole 25 EC was completely able to inhibit mycelial growth at 50ppm, remaining all the other fungitoxicants were also quite effective in inhibiting the mycelial growth in-vitro. Overall, it was seen that the application of bioagents significantly decrease the disease severity and increase the yield parameters of crop.