Kinetics of nitrate absorption in grape (Vitis species), mango (Mangifera indica) and banana (Musa × paradisiaca).
Murthy S. V. K., Kotur S. C.
Author Affiliation: Indian Institute of Horticultural Research, Bangalore, Karnataka 560 089, India.
Indian Journal of Agricultural Sciences 71 : 650-651
Abstract : An experiment was conducted during 1994-96 to study the kinetics of nitrate absorption of cultivars and rootstocks of grape (Vitis spp.), mango (Mangifera indica), and banana (Musa paradisiaca). Rooted cuttings of grape (V. vinifera cultivars Anab-e-Shahi and Thompson Seedless; V. rupestris cultivars St. George and 1613) and mango seedlings were grown in acid-washed quartz-sand and their roots were immersed in nitrate-nitrogen solution. In banana cultivars (Cavendish, Robusta, Monthan and Elakki), the roots were exposed in the field-grown plants and immersed in a nutrient solution. The maximum rate of absorption, which confers to the capacity of the root to respond to higher concentration of nitrate-nitrogen in the rhizospheric solution, was very high in all the cultivars of banana (216.6-1312 pmoles/litre) compared to the cultivars of grape (0.77-9.45) and mango (1.55-14.58). The affinity of nitrate ions on roots was stronger in grape (22.86-150.15 µ moles/litre) than mango and banana (837 and 2613). The average net inflow of nitrate into the roots were significantly higher in banana (20.01-61.97 pmole cm-1 second-1) compared to grape (0.63-3.78) and mango (0.17-0.59).