Influence of weather parameters on Anthracnose in black pepper (Piper nigrum L.) in the upper Brahmaputra valley zone of Assam

Abstract

Black pepper (Piper nigrum L.) production faces several challenges due to various diseases, with anthracnose being the most significant. It is caused by Colletotrichum gloeosporioides (Penz.) Penz. and Sacc., a fungal plant pathogen that leads to severe infections in black pepper plants, both in nurseries and in the field. The occurrence of anthracnose disease is highly influenced by weather conditions. Epidemiological studies were conducted at Assam Agricultural University, Jorhat, Assam from 2019 to 2021 to determine the impact of weather factors such as temperature, rainfall, rainy days, and relative humidity on anthracnose incidence in seven different black pepper varieties. Upon analyzing the recorded data, it was found that rainfall, minimum temperature, rainy days, and morning relative humidity are the most significant contributors to disease occurrence. However, the role of maximum temperature, evening relative humidity, and bright sunshine hours was statistically non-significant. Data from 2019 and 2020 were further analyzed using stepwise multiple regression to estimate anthracnose incidence in individual black pepper varieties. These regression models were subsequently validated using data of 2021. The root mean square error values varied between 0.0001 and 0.0011, indicating that the models are acceptable.