%0 Journal Article
%T A PRELIMINARY STUDY ON IMMATURE NUTFALL OF COCONUT WITH REFERENCE TO PEST DAMAGE
%J -
%D 1995
%R 10.4038/cocos.v10i0.2138
%X Buttons and immature nut shedding before and after fertilization is a common problem in coconut. In general, about one third of the buttons produced in an inflorescence develop into mature nuts. The number of buttons produced in a bunch often exceeds the number of nuts reaching maturity. Immature nutfall in coconut has been attributed to various factors such as natural capacity for production, physiological and environmental factors, and pest damages. It was reported that a coconut inflorescence commencing with an average of 16 female flowers or potential nuts loses 2 4% during the first two months, 40% during the second two months and 2% during the third two months of their development (Abeywardene and Mathes, 1971). Fungal infection has been identified as one of the main causes of immature nutfall in coconut (Quillec et al, 1984). Several species of insects have also been recorded as pests of immature nuts, which cause developing nuts to shed (Fernando and Kanagaratnam, 1989). However, no attempts have been made to quantify the effect of insect pests and pathogens on immature nutfall in coconut. The present study was undertaken to categorize and quantify the pest damages which are responsible for immature nutfall in coconut. Total of twenty healthy palms were selected and a nylon net basket was hung just below the selected inflorescence in each palm soon after the opening of the inflorescence. Fallen nuts were collected daily during the first two months and at weekly intervals thereafter over a six month period, and were then categorized according to the cause of nutfall. Three major factors, namely microbial infections, insect pest damages and physiological reasons were identified as predominant causes for nut shedding. Microbes, especially fungal infections were identified by the light brown to dark brown patches with water soaked appearance and the presence of mycelium in the perianth region and in the inner tissues. Isolations were performed on discoloured tissues. Insect attacks were identified by their presence, feeding signs, larval tunnels, webbing and scrapping marks on the immature nuts. Immature nuts fallen due to physiological disorders were identified by their healthy appearance and characteristic uniform browning of the nuts. ation is a common problem in coconut. In general, about one third of the buttons produced in an inflorescence develop into mature nuts. The number of buttons produced in a bunch often exceeds the number of nuts reaching maturity. Immature nutfall in coconut has been attributed to various factors such as natural
%U https://cocos.sljol.info/articles/10.4038/cocos.v10i0.2138/