Abiotic Environmental Factors Conducive for Wheat Leaf Rust Disease: Finding the Source of Resistance for its Management
Author(s) : Muhammad Iqbal, Muhammad Asim and Muhammad Ehetisham ul Haq
Wheat (Triticum aestivum L.) is the main source of food for the world population. The present study was aimed to find resistant germplasm against the leaf rust disease by screening the available varieties/lines and to study the relationship between abiotic environmental factors and leaf rust disease severity. Four hundred and eighty-seven wheat varieties/lines were screened against leaf rust disease under nursery conditions. No variety/line was found immune to the disease. Only four varieties/lines were resistant, six were moderately resistant, ninety-six varieties/lines were found moderately susceptible and 380 were found susceptible against the leaf rust infection. The relationship between maximum temperature, minimum temperature, relative humidity, rainfall and leaf rust disease severity on three susceptible wheat varieties (Hashim-08, SKD-1 and Khiram) was assessed using linear regression models. A strong negative linear relationship between leaf rust disease and maximum temperature was observed. Maximum disease severity was noted at 23-24 maximum temperature (oC). The relationship between leaf rust disease severity and minimum temperature was found positive and maximum disease severity was recorded at 15-16°C. Disease severity increased with the decrease of relative humidity. Maximum disease severity was recorded when relative humidity was between 84-85%. Maximum disease severity was recorded when rainfall was between 1-2mm.