Effects of bunch trimming and double bunch covering on yield of bananas during winter in New South Wales

Abstract

Bunch trimming (removal of male bud and several distal hands from bunches soon after flowering), and double covering (use of 2 bunch covers simultaneously) of banana bunches that emerge during winter in northern New South Wales could have the potential to increase the size, and hence grade and price of harvested fruit. Consequently bunches were either trimmed to 6, 8 or 10 hands or left untrimmed (male bud retained), and either single or double bunch covers were applied on a commercial plantation on 3 occasions during winter, and the effects on fruit size and quality were recorded. Bunch emergence to bunch harvest interval was reduced by an average of 5 days by bunch trimming. Finger length increased with increasing severity of bunch trimming, with the average length for the top 6 hands increased by 2.3% (P<0.01) for the 10-hand treatment to 6.1% (P<0.001) for the 6-hand treatment. Finger weight increased with increasing severity of bunch trimming, with weights for the top 6 hands increased by up to 14% (P < 0.001) on the 6-hand treatment. Double covering increased finger weight of the top 6 hands by 4% (P < 0.01). Trimming to 10, 8 and 6 hands increased the yield per bunch of extra large grade fruit by 18, 23 and 39% respectively. Double covering did not affect the yield of extra large fruit significantly. After excluding hands suffering from the mixed ripe condition, the 6-hand treatment yielded 51% more marketable extra large fruit than untrimmed bunches. Potential profitability of the treatments depended on price scenario. When prices were low the 6-hand treatment appeared most profitable, but at higher prices the 10-hand treatment would be preferable. Double covering appeared not to be worthwhile for all price scenarios used.