STUDY ON SEEDLING DISEASES OF JUJUBE

Abstract

Jujujbe, one of the major fruit crops of Bangladesh, was surveyed during the research period of20 I 0-20 II. Survey was conducted to see the seedling diseases and effect of temperature, relative humidity and Rainfall on the incidence and severity of the diseases. Four different diseases viz. Alternaria leaf spot, Powdery mildew, Sooty mold and Rust of jujube were recorded and the diseases were caused by Alternaria alternate, Oidium erysiphoides, Cladosporium zizyphi and Phakopsora zizyphivulgaris respectively. Incidence and seveirity of the diseases differed significantly from locations to locations as well as season to seasons. The highest prevalence of alternaria leaf spot was recorded at Gazipur (01=36.17% and DS=24.06%) and the lowest was recorded at Khagrachari (01=29.19% and DS=20.74%). The highest incidence and severity of rust of jujube was recorded at Dhaka (0]=19.68% and DS=14.62%) and the lowest incidence was recorded at Khagrachari (01=16.20%), lowest severity was recorded at Barisal (DS=11.67%). The highest incidence and severity of powdery mildew of jujube was recorded at Khagrachari (01=3 I .68%) and Barisal (DS:::20.13%) and the lowest was recorded at Dhaka (.0]=26.99% and DS=IS.33%). The highest prevalence of sooty mold was recorded at Gazipur (DI=6.79% and DS=4.28) and the lowest was recorded at Khagrachari (01=4.28% and DS=2.46%). The lowest prevalence of Alternaria leaf spot disease was recorded in January and higher in October. A positive correlation was observed between prevalence of Alternaria leaf spot with temperature, relative humidity and rainfall. The highest prevalence of Powdery mildew disease was recorded in July and no disease was observed in the month of October. A negative correlation was observed on prevalence of Powdery mildew with temperature, relative humidity and rainfall. The highest prevalence of Sooty mold disease was recorded in April and no disease was found in the month of July and October. A negative correlation was observed on prevalence of Sooty mold with temperature, relative humidity and rainfall. The highest prevalence of Rust disease was recorded in April and no disease was found in the month of October. A negative correlation was observed on prevalence of Rust with temperature, relative humidity and rainfall.