MANGO QUICK DECLINE MANIFESTATION ON VARIOUS CULTIVARS AT PLANTS OF PARTICULAR AGE IN THE VI

Abstract

Quick decline of mango caused by various species of fungi viz. Lasiodiplodia theobromae, Ceratosystis fimbriata and Phomopsis sp. is said to be the most serious disease reportedly present in mango orchards of Pakistan. The present survey was conducted to evaluate disease intensity of quick decline in the heart of mango zone of Punjab i.e. Multan, its varietal prevalence, age response of various cultivars and predisposing factors prevailing in the mango orchards to facilitate the disease. Survey results showed highest disease intensity (15.02%) in the visited orchards of North zone followed by West zone (14.10%), East zone (13.33%) and minimum disease severity index (9.88%) was recorded at South plane. The mango cultivar, Chaunsa was found to be the most susceptible to disease, recorded to be the most predominant variety in the orchards. Maximum prevalence of disease (32.20%) was calculated on cultivar Chaunsa followed by Fajri, Malda, and Langra. The minimum disease severity (0.83%) was noted on Almas followed by Sensation, Mahmood Khan, Shan e Ali and Armughan which proved to be the tolerant cultivars against the disease. Considering a possible variation in age response of mango plants, two particular age levels were evaluated on the basis of symptom characterization. The findings showed that some varieties have the ability to overcome the disease at the specific age. Variability in severity of disease in different mango cultivars at varying age could be attributed to possible natural tolerance against the disease. The investigations showed predisposing factors to play the key role in the development of disease. This study provides fresh information on the core issue, prioritization for cultivation of a particular variety at optimal age limits.