Evaluation of banana cultivars for sheath fibre yield and quality

Abstract

The research work “Evaluation of banana cultivars for sheath fibre yield and quality” was carried out in the Department of Fruit Science, College of Agriculture, Vellanikkara during the academic year 2019-2021. As part of this experiment, biomass produced by different banana cultivars and their fibre yield were recorded. The fibre obtained from different cultivars were analysed for their physical and biochemical characters. Significant variation was observed among the cultivars belonging to different genomic groups with regard to biomass production. The highest values for whole plant weight (45.20 kg), pseudostem weight (30.19 kg) and leaf weight (6.42 kg) were recorded in Elavazha, whereas the highest rhizome weight was recorded in Karpooravally (10.63 kg). Maximum plant biomass production was noticed in cultivars with BB genome (42.24 kg) and least in cultivars with AA genome (12.08 kg). In general, cultivars with ‘B’ genome were found to produce higher biomass than cultivars with ‘A’ genome. The number of fibre extractable sheaths were found to vary (10-16) among the different cultivars. The maximum number of fibre extractable sheaths was recorded in cultivars Kunnan, Njalipoovan, Mysore Poovan and Monthan (16 each) followed by Elavazha and Grand Naine (15 each). The percentage of fibre extractable pseudostem among the different cultivars was found to be in the range of 41.52% (Kunnan) to 76.18% (Grand Naine). Sheath weight was found to be correlated with the weight of leaves, pseudostem, rhizome and whole plant and the average sheath weight was highest in Karpooravally (1083.57 g) and Elavazha (1072.89 g) followed by Attikol (1026.43 g). It was observed that, sheath weight was higher in the middle layers and showed a trend reducing towards outer and inner layers in all banana cultivars except for Chenkadali in which sheath weight of the outer layers were also higher. Among the methods of extraction, mechanical extraction was found to be better compared to manual method with respect to fibre yield. Fibre yield was directly correlated with sheath weight in each cultivar and as in the case of sheath weight, fibre yield was also found to be higher from middle sheath layers than that from outer and inner sheath layers. In cultivar Chenkadali, higher fibre yield was recorded from both outer sheaths and middle sheaths. Apart from such exception, the superiority of ‘B’ genome with respect to fibre yield was unravelled through higher yield and higher recovery percentage in Elavazha and Attikol. Fibre yield from the whole plant was comparatively high in Elavazha (157.38 g) followed by Chenkadali (146.97 g). Physical characters of banana fibres such as tex and diameter did not vary with respect to the method of extraction. However, variation was there among cultivars and also depending upon the position of sheath layer in pseudostem. Tex of fibre from different cultivars ranged from 5.50 to 21.70, whereas diameter ranged from 0.06 mm to 0.18 mm. Tex and diameter of the fibre were found to be positively correlated. With regard to TSS content of pseudostem juice, it was found to be very less in all the cultivars, with a comparatively higher value in Elavazha (1.37ºBrix). The values recorded for pH (5.32 to 6.87) and acidity of pseudostem juice of different cultivars indicated that the juice is slightly acidic in nature. Moisture content in freshly extracted fibre ranged from 49.98% to 77.78% and was found to be high in cultivars belonging to AB and ABB genomic groups. Significant variation was observed among the cultivars with respect to cellulose, lignin, carbohydrates and pectin in dry fibre. The cellulose content in fibre of different cultivars ranged between 43.86% and 68.70%, lignin content ranged between 11.64% and 39.23%, carbohydrate content ranged between 1.05% and 2.76% and pectin content ranged between 1.40% and 3.80%. The cellulose content in fibre was found to be high in cultivars with BB genome and lowest in cultivars with AAA genome. Lignin content was negatively correlated with cellulose content and ‘A’ genome was found to contribute more towards lignin content than ‘B genome. Pectin content was also positively correlated with lignin content. Among sheath layers, cellulose content was higher in fibre from inner sheath layers, whereas lignin and pectin content was higher in the outer sheath layers.