Effect of integrated nutrient management on quality leaf production in mulberry (Morus alba) under rainfed, alluvial soil conditions

Abstract

A field experiment was conducted during 1998-2002 at the Central Sericultural Research and Training Institute, Berhampore (West Bengal), under rainfed, Gangetic alluvial soil conditions, to study the effect of integrated nutrient packages on growth characters, leaf yield, leaf quality, N, P and K uptake by leaves in mulberry (Morus alba L.) utilizing arbuscular mycorrhizal fungi inoculated 'S1' mulberry saplings, Azotobacter chroococcum, Eichhornia compost, green manuring with Sesbania rostrata and Crotalaria juncea L., leguminous cover crop with cowpea [Vigna unguiculata (L.) Walp.] and rice bean [Vigna umbellata (Thunb.) Ohwi & H. Ohasi] and 2 levels of nitrogen and potassium and 1 level of phosphorus. Significant differences were observed among the treatments for plant height, branches/plant, leaves/plant, leaf area, leaf yield, leaf moisture, total soluble sugar, nitrogen, phosphorus and potassium uptake in leaf except total soluble protein. Season x treatment and year x treatment interactions were also found significant except for total soluble protein and total soluble sugar content in leaves. However, branches/plant, leaves/plant, leaf yield, leaf area, leaf moisture, total phosphorus and potassium uptake by leaves were found moderate owing to application of recommended dose of N, P and K. The leaf quality did not exhibit much variation among the treatments and controls. However, some of the important quality parameters recorded maximum values in different treatments in comparison with the controls. Arbuscular mycorrhizal fungi inoculated 'S1' mulberry saplings planted at 90 cm x 90 cm spacing with 45 cm and 60 cm pruning height in alternate crop along with green manuring with Crotalaria juncea during rainy season, leguminous cover crop with Vigna umbellata during the winter season and application of 50% of recommended doses of N and P and full dose of K significantly increased plant height (124.41 cm), branches/plant (7.49), leaf yield (9.71 tonnes/ha/year), total soluble sugar (43.14 mg/g fresh weight) and total soluble protein (20.54 mg/g fresh weight) content in the leaf and N (52.35 kg/ha/year), P (7.56 kg/ha/year) and K (29.89 kg/ha/year) uptake by leaves. In addition, the leaf yield increased by 13.57% and the expenditure of mulberry cultivation was reduced by 31.89%.