Effect of bunch protection material and bagging time on the yield of 'Nanica' banana and chilling control

The bagging of banana bunch can control chilling injury (CI) in the field, which causes browning of banana peel. The purpose of this study was to evaluate the effect of changing the bunch protection material and bagging time on the yield of 'Nanica' banana (AAA) and the occurrence of CI. The experiment was conducted in Jacupiranga, SP, Brazil. The experimental design was completely randomized design arranged in a 2 x 2 x 6 factorial scheme with eight replicates, two bunch formation periods (autumn-winter and winter-spring), two bagging times (early, before the opening of bracts, and late, after complete opening) and six treatments. Treatments were polyethylene bags with different thickness (blue bags of 3μ in thickness and black bags of 6, 8 and 10μ in thickness combined with white non-woven fabric, black bag of 10μ in thickness combined with blue polyethylene bag 5μ in thickness impregnated with insecticide) and non-bagged banana. The change of sunlight transmission with black polyethylene bags of different thickness promoted a small increase in fruit peel temperature (0.14 to 0.57°C) on colder days (8.72°C), reduced CI index and improved peel brightness (L*) and ho (hue angle), although it did not affect bunch mass. However, in late winter, sunburn increased fruit losses. Sunlight transmission in fruit peel was correlated with CI index (r=0.92*), L* (r =-0.77*) and phenols (r=0.85*). Despite not controlling CI, early bagging is recommended for increasing peel L*.