Vol. 10, Special Issue 11 (2021)

Author(s):
Gowdar SB, Patil MB, Gururaj Sunkad, Pramesh D, Masthana Reddy BG and Sujay Hurali

Abstract:
Rice (Oryzae sativa L.) is a versatile crop that may be produced in various agro-climatic conditions worldwide. Rice is India's most prominent cereal food crop, and it plays critical role to the country's food grain supply. Among the diseases, stem rot [Magnaporthe salvinii (anamorph: Sclerotium oryzae) Catt.] has emerged as a serious threat to rice cultivation has become the most devastating disease, causing significant yield losses in the rice crop. To know the correlation of weather and soil variables with the incidence of stem rot during the entire crop season on susceptible variety BPT-5204 at ARS, Gangavathi. The observations were recorded at weekly interval (SMW - Standard Meteorological Weeks) till harvest. Soil temperature, soil moisture, rainfall and rainy days were recorded at weekly interval to find out correlation with the stem rot. The maximum soil temperature (0.88**) during Kharif 2017-18 followed by minimum soil temperature and maximum soil temperature (0.69** and 0.86**) during Rabi/summer 2017-18 were positively correlated with disease incidence. During Kharif 2017-18, minimum soil temperature (-0.74**), rainfall (-0.60**), and rainy days (-0.64**) were negatively correlated with disease incidence. During Kharif 2018-19, minimum soil temperature (-0.60*) and rainy days (-0.51*) were negatively correlated with disease incidence. The Area Under Disease Progress Curve (AUDPC) was be calculated for stem rot incidence on BPT-5204. The Rabi/summer 2017-18 season had a low AUDPC score (1365.40), indicating a lower incidence of terminal disease (33.6%). In Kharif 2017, a high AUDPC score of 1510.60 was observed, indicating a high incidence of terminal disease (42.00%).