Regulation of leaf pruning to optimise leaf and bunch harvest in musa (AB Group) njalipoovan and (AAB Group) palayankodan

Abstract

The investigation on Regulation of leaf pruning to optimise leaf and bunch harvest in Musa (AB group) Njalipoovan and (AAB group) Palayankodan was conducted at the Department of Horticulture College of Agriculture Vellayani Thiruvananthapuram during 1993 94 in order to study the effect of leaf pruning on growth yield and fruit quality of Njalipoovan and Palayankodan bananas Studies revealed that the plant height in Njalipoovan was comparatively less affected by leaf pruning than Palayankodan Plant height in both the varieties was higher with less severe pruning treatments The plant girth total number of leaves per plant and phylachron were not influenced by the leaf pruning regimes imposed Leaf longevity increased slightly with the severity of pruning Njalipoovan responded more to leaf pruning than Palayankodan with regard to leaf longevity The functional leaf area leaf area index and leaf area duration decreased significantly with the severity of leaf pruning in both the cultivars Leaf pruning after 15 days of unfurling less adversely affected the relative growth rate in both the cultivars The time taken for bunch emergence increased and the time taken for bunch maturity decreased when the extent

of lamina removed was more or the period of retention was short in both Njalipoovan and Palayankodan The crop duration in Njalipoovan decreased when the period of retention of leaves was longer The sucker production and dry matter production in both the cultivars were higher with lesser severity of pruning The bunch characters of Njalipoovan were less adversely affected by the leaf pruning treatments imposed than Palayankodan The number of hands fingers bunch weight and yield per hectare in both the cultivars decreased with the increase m the severity of pruning The finger length finger girth finger weight peel weight pulp weight and pulp/peel ratio of the fruits were also adversely affected by severe pruning treatments Abnormalities in fruit shape and fruit filling were observed as a result of the leaf pruning treatments in Palayankodan The fruit quality of cv Palayankodan was more affected by severe pruning than that of cv Njalipoovan In both the cultivars severe pruning treatments resulted in decreased quality m terms of TSS reducing sugars total sugars and sugar/acid ratio The acidity of the fruits was not

significantly affected in Njalipoovan The non reducing sugar content and the green life of the fruits decreased with Increase m the extent of leaf area removed but the time of pruning had no significant influence on these characters The content of major nutrients in the plant parts decreased with the increase m the severity of leaf pruning The cost of cultivation was higher in the treated plants The returns from fruits and the total returns per hectare was highest m the control plants The net returns was higher in Njalipoovan compared to ‘Palayankodan The studies thus indicated that in general leaf pruning was not a desirable practice from the economic point of view in Njalipoovan and Palayankodan However the loss of lamina upto 50 per cent after 30 days of unfurling had less deleterious effects compared to more severe loss of leaf area Njalipoovan exhibited more ability to withstand the adverse effects of leaf pruning than Palayankodan