Management of Fusarium wilt of chillies caused by fusarium soxysporum f. sp. Capsici in relation to soil and environmental factors

Abstract

Fusarium wilt is the most destructive disease of chilli pepper in all chilli growing areas of the world. Soil and environmental factors play a crucial role in the development of disease. Knowledge of soil and environmental factors and identification of resistant sources within available germplasm against Fusarium wilt disease is very necessary. Thirty-three varieties/ advanced lines were collected and were evaluated in sick field for two years (2012-13 & 2013-14) under RCBD. Two advanced lines (10553 & 10549) expressed resistant and some advance lines/varieties (1777, 4828, 10559, 1776, Maxi and Desi) exhibited susceptible to highly susceptibility response towards Fusarium wilt of chilli pepper during both years. Maximum soil and air temperature, minimum soil and air temperature, wind speed and soil moisture expressed positive whereas relative humidity negative and rainfall exhibited non-significant correlation with disease development on all varieties of chilli pepper during two years. Maximum disease was recoded at maximum soil (30- 35oC) and air temperature (25-30 oC). Disease predictive model based upon two years soil and environmental data was developed which explained 82.7 % variability in disease development. Regression models on five varieties/ advanced line (Desi, Skyline, Sanam, Maxi and10553 were developed, which were in close conformity with observed values of disease incidence during two years models. Two sources of OM (cow and poultry manure) at four levels were evaluated against Fusarium wilt. Both expressed significant results but the soil in which cow manure was used (as source of OM) expressed minimum disease incidence at all levels. Similarly among three types of soil (sandy soil, clay soil and sandy loam soil), sandy loam soil expressed minimum disease incidence. For management of Fusarium wilt of pepper six chemicals (Carbendazim, Benomyl, Topsim-M, Difenconazole, Nativo and Alliete), three antagonistic organisms (Trichoderma viride, T. koingii and T. harzianum) and five plant extracts (Moringa oleifera, Brassica compastris, Azadirachta indica, Zingiber officinales and Trachyspermum ammi) were evaluated under lab. conditions. Among chemicals (Carbendazim), plant extracts (M. oleifera), antagonistic organisms (T. viride) expressed significant results under lab. and greenhouse conditions. Mixture of nutrients NPK (Compound) and B, Zn, Fe (Nutritop) and four growth regulators ( Salicylic acid, K2HPO4, KH2PO4 and citric acid) were evaluated under greenhouse conditions. Among nutrient mixture, Compound and growth regulators, salicylic acid expressed minimum disease incidence. Carbendazim, M. oleifera, T. viride, salicylic acid and Compound were also evaluated under field conditions against Fusarium wilt of chilli pepper and Carbendazim exhibited minimum disease incidence.