SURVEY ON THE MAJOR DISEASES OF WATERMELON IN TWO SELECTED DISTRICTS OF BANGLADESH

Abstract

A field survey was conducted to identify the major diseases of watermelon in the year of 2020 and 2021 at Subarnachar Upazila in Noakhali district and Dashmina Upazila in Patuakhali district. The laboratory works has done at Central Laboratory of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh. Twenty villages from Ten Unions of Noakhali and Patuakhali districts were considered for survey and investigation of major diseases of watermelon. Altogether, sixty farmers were interviewed from Noakhali and Patuakhali district of Bangladesh. The incidence and severity of diseases of watermelon varied significantly among the locations. Depending on the disease incidence and severity, the major diseases of watermelon were leaf curl, leaf spot, foot and root rot. In leaf spot disease in both districts, the highest disease incidence and severity were 35.10% and 10.33% which were recorded in West Charbata at Noakhali district, respectively. In case of leaf curl disease of watermelon the highest disease incidence and severity were recorded in South Kocchopiya and Char Aminul Haq that were 74.53% and 18.33%, respectively. The highest powdery mildew disease incidence 11.33% and severity 4% was observed in South Kocchopiya in Noakhali. In case of foot and root rot disease, the highest disease incidence and severity was recorded in Auliapur at Patuakhali district which were 20.66% and 15% in West Charbata, Noakhali district, respectively. The highest disease incidence of leaf mosaic were recorded in South Kocchopiya at Noakhali district and Gochani at Patuakhali district which were 16.67% and disease severity were 2.33% at Char Mujib and South Kocchopiya in Noakhali while the lowest severity of leaf mosaic 1.33% was recorded in Gochani, Patuakhali district. In total, five diseases were recorded and identified in field conditions viz. Leaf spot caused by Alternaria alternata, leaf curl caused by chlorotic stunt virus, powdery mildew caused by Oidium sp, foot and root rot caused by Fusarium oxysporum and leaf Mosaic caused by virus. Considering the amount of severity of diseases, foot and root rot and leaf curl were major diseases occurred in watermelon fields in Noakhali and Patuakhali district, respectively. Moreover, in-vitro conditions fungi viz. Fusarium oxysporum, Aspergillus spp., Alternaria alternata, Rhizopus stolonifer and Chaetomium sp. were isolated and identified from the seeds of watermelon mixed varieties revealed by seed health test. The socio-economic status of watermelon farmer’s in Bangladesh revealed that the highest percent of farmers used 2 to 3 ha of land for watermelon cultivation and most of the money was used to prevent the watermelon from disease, insects and weeds which was about 28,000 Tk/ha.