INCIDENCE OF COCONUT DISEASES IN SELECTED AREA OF BANGLADESH AND STUDY OF BIOCONTROL BASED MANAGEMENT PACKAGE AGAINST BASAL STEM ROT OF COCONUT

Abstract

A survey study and lab experiment was conducted in this study. The survey study was held on four district. Three are coastal area viz. Noakhali, Barisal and Patuakhali and another is in SAU campus in Dhaka. The lab experiment was conducted in Molecular Biology and Plant Virology Laboratory, Department of Plant Pathology, Sher-e-Bangla Agricultural University, during January 2018 to March 2019. The study was aimed to demonstrate occurrence and incidence of basal stem rot and foliar diseases of coconut in surveyed area and to develop a biocontrol-based management package against basal stem rot. The disease incidence of basal stem rot was measured 65%, 64.44%, 60.83%, 49.17%, in SAU, Patuakhali Noakhali and Barisal respectively. The disease severity was 33.88%, 30%, 26.67%, and 24.58% respectively in Noakhali, SAU, Patuakhali and Barisal. The incidence of foliar diseases was estimated 85%, 85%, 78.61%, and 77.78% respectively in Noakhali, SAU, Patuakhali and Barisal. The disease severity was 39.13%, 33.56%, 28.33% and 24.13% respectively in Noakhali, Patuakhali, SAU and Barisal. The highest incidence of basal stem rot (27.5%) and leaf disease (19.2%) was found in loamy soil. The highest disease incidence was found at the soil pH 6-7 and the incidence were 26.75% and 22.45 respectively. The highest incidence of basal stem rot (24%) and foliar diseases (18%) was found in plant age group 36-40 years. In total 120 root samples and 90 leaf samples were collected for aseptic isolation. The isolated pathogens from root samples were identified as Ganoderma sp. while three pathogens were isolated from leaf samples which are Pestalotia sp., Curvularia sp., and Alternaria sp. In total 32 Ganoderma infected plants from SAU campus were selected and treated with 3 management package of different bioagent and botanicals viz., Trichoderma viridae, cattle urine, masturd oil cake, neemseed extract and garlic extract. After 5 months of treatment root samples were collected and investigated for existence of pathogen .Among the three combinations mustard oil cake + neemseed extract + Trichoderma viridae and cattle urine gave the best performance and disease inhibition were 35% and 52.5% over control. The result of the present study revealed that basal stem rot and foliar diseases are frequently occurred in the survey areas and cattle urine was found effective in the management of this disease in coconut.