Effect of bunch trimming and leaf removal at flowering on maturity bronzing, yield, and other aspects of fruit quality of bananas in North Queensland

Abstract

This study examined the effects of bunch trimming and leaf removal on rate of bunch filling, severity of the maturity bronzing fruit peel disorder, and other yield and quality paramaters. There were 4 levels of leaf removal (4, 7, 10, 13 leaves retained) and 4 levels of bunch trimming (male bud retained, male bud removed, male bud and 2 hands removed, male bud and 4 hands removed) imposed on banana bunches at flowering. The experiment was carried out at South Johnstone, North Queensland. The 320 plants in the trial produced a range of fruit-filling rates that were largely unrelated to the imposed treatments. With the exception of the duration of fruit filling and extra large fruit weight, leaf removal and bunch trimming acted independently on the attributes measured. Leaf removal reduced maturity bronzing and bunch trimming increased it. Increased bronzing was associated with increased finger length, possibly due to epidermal cells in the fruit peel elongating beyond their elastic limit. Bunch trimming reduced bunch weight and but did not improve the quantity of extra large fruit. Leaf removal reduced bunch weight when <10 leaves remained, due largely to a reduction in finger length throughout the bunch. Fruit greenlife was also reduced by leaf removal. Therefore, the reduction in maturity bronzing achieved by leaf removal is of no immediate benefit to growers. Removal of the male bud increased bunch weight due to an increase in finger length. Dry weight analysis indicated that the male bud represented a significant competing photosynthetic sink. For maximum yield of quality fruit, growers should remove the male bud, practice no bunch trimming, and ensure the retention of at least 9-10 leaves from flowering to harvest.

Hand position on the bunch and source–sink ratio influence the banana fruit susceptibility to crown rot disease

“…We confirm here that So-Si ratio changes have a significant effect on fruit morphology, as previously demonstrated in several studies (Daniells et al, 1987(Daniells et al, , 1994Israeli et al, 1995;Johns 1996;Kurien et al, 2000;Jullien et al, 2001b;Mouen Bedimo et al, 2003;Chillet et al, 2006). We reveal, furthermore, a new effect of a So-Si ratio change on the fruit quality potential: when the sink is decreased by removal of many hands, the fruit susceptibility to crown rot decreases.…”

Effect of Pulp Cell Number and Assimilate Availability on Dry Matter Accumulation Rate in a Banana Fruit [ Musa sp. AAA group 'Grande Naine' (Cavendish subgroup)]

“…However, the growth rate of banana fruit also seems to vary with the source/sink ratio during fruit growth. Removal of hands (thereby decreasing the sink size: Meyer, 1975;Daniells et al, 1994;Johns, 1996), leaf shading (reducing resource availability: Israeli et al, 1995) or bunch bagging (increasing sink demand by elevating the air temperature: Turner and Rippon, 1973;Ganry, 1975;Johns and Scott, 1989a, b;Daniells et al, 1992;Jannoyer and Chillet, 1998;Turner, 1998) modify fruit growth rates and, consequently, the commercial harvest date.…”

Simulation of defoliation caused by Black Sigatoka in the yield and quality of banana 'Nanica ' fruits

“…Thus, the accumulation of mass of the bunch with increasing number of leaves occurred concomitantly with the increase of the mass of the fruit of 4 th hand, which was the result of increased fruit size. In tropical conditions, the defoliation of banana 'Nanica' did not affect bunch mass and fruit size (VARGAS et al, 2009;GONZÁLEZ et al, 2012); however, in subtropical, there was a reduction in plants with less than 10 leaves (DANIELLS et al, 1994). Regardless of period, the bunch filling time increased with the number of leaves, but with a variation of only 15 days between plants with higher and lower number of leaves ( Figure 1F).…”

“…This indicated that the increased availability of assimilates due to the higher number of leaves promoted the highest growth in fruit size ( Figure 1E) and extended the bunch filling period ( Figure 1F) as a consequence of physiological maturity, resulting in longer time to complete ripening ( Figure 1G). DANIELLS et al (1994) and RAMIREZ et al (2008) reported no effect of defoliation on postharvest period, while GONZÁLEZ et al (2012) reported no effect on physical-chemical characteristic of the fruit.…”