An investigation was conducted for obtaining information on the reduction of postharvest losses, pattern of physical, biochemical and mineral content changes, storability as well as shelf life of postharvest mango. The trials included four different experiments involving two factors where variety was a factor comprising of Langra and Khirshapat. These varieties were treated with different postharvest treatments viz., control, paraffin coating, perforated polyethylene cover, unperforated polyethylene cover, hot water (55 1)0C, low temperature in refrigerator (4 1)0C; different doses of Maleic hydrazide, GA3 and Bavistin DF solution. These experiments were laid out in Randomized Complete Block Design with three replicates. Different postharvest treatments subjected to the investigation demonstrated significant variation in most of the physicochemical properties and shelf life of mango. Low temperature in refrigerator was the best inhibitor of ethylene synthesis that delayed ripening and prolonged shelf life. The second suitable method was found to be 400 ppm of GA3 which is cost effective and might easily be adopted by common farmers for mango preservation.

Taxonomic investigation of the family Asteraceae (Compositae) growing throughout the Rajshahi Division situated in the northern part of Bangladesh was carried out. A total of 36 species under 29 genera of the family Asteraceae were collected and identified. Of the total number of species, 8 were found under cultivation and 28 grow wild in the study area. Ageratum conyzoides, Blumea lacera, Eclipta alba, Tridax procumbens, Vernonia patula and Xanthium indicum were recorded as densely populated and Mikania cordata as the only climbing species. Blumea laciniata and Wedelia trilobata have been reported here for the first time from Rajshahi Division, and Perthenium hysterophorus as a new record from Bangladesh. Of the total number of species in the study area, 97.22% were recorded in Rajshahi district; 77.77% in Natore district; 75% in Nawabgonj district; 61.11% in Naogaon district; 72.22% in Bogra district and 66.66% in Joypurhat district. Finally, a new system of classification of the family Asteraceae has been proposed on the basis of morphological, anatomical and floral characters.