FIELD RESPONSE OF KOHLRABI VARIETIES AGAINST MAJOR FUNGAL AND VIRAL DISEASES

Abstract

A field experiment was conducted at central farm and plant pathology lab, Shere-Bangla Agricultural University, Dhaka-1207 from November 2020 to March

2022

to study the field response of selected kohlrabi varieties against major fungal and viral diseases and identification, isolation of causal organisms of fungal diseases. Five varieties were selected for this experiment viz- Challenger, Goliath, Bankim, OP Hybrid and Early star, which was collected from Siddik bazar, Dhaka. The field experiment was carried out in RCBD (Randomized Complete Block Design) with four replications of each variety in Robi season. During field response, three diseases were observed at field condition, where two fungal and one viral disease identified compared with international literature. They were- Wilt (caused by Fusarium oxysporum), Alternaria leaf spot (caused by Alternaria brassicae) and Mosaic disease (caused by Turnip Mosaic Virus). Wilt was observed at seedling condition where variety Bankim was the most susceptible (1.25%) and lowest incidence was recorded at OP and Early star variety (0.25%). In case of Alternaria leaf spot, among five varieties Challenger showed maximum infection (87.47%) and minimum was seen in Bankim variety (64.45%). In case of growth and yield character significant variation among all varieties were found. Maximum yield was observed in variety Bankim (9.80 t/ha) and minimum yield was recorded in variety Challenger (7.46 t/ha). Respectively, Yield loss was maximum in variety challenger (45%) and minimum in Bankim (20%). In case of viral disease, TuMV had the most impact on variety challenger (8.32%) and it greatly reduced its average fruit weight resulted as 45.12 gm and lowest disease incidence was observed in variety Bankim (1.09%) and their average fruit weight leads to 119.67 gm. Considering field response against all diseases among all varieties, variety Bankim has minimum percentage of incidence against all diseases as well as it gave highest yield in both fungal and viral infections. So Bankim reflects resistance against all disease response compared to other selected varieties.