Boron Deficiency in Mango (Mangifera indica L.): A Cause Delineation Study in Acidic Soils of Maharashtra, India

Boron deficiency is a major production constraint of Mango cv Alphonso in western coast, Maharashtra, India. The soils are sandy-loam, light, acidic in reaction and receive high annual precipitation of above 2,500 mm. The leaf and soil B status was low with an average of 23 and 0.25 mg kg^?1 respectively. About 60% of the orchards were found to be deficient in B. The B adsorption study using Langmuir adsorption isotherm revealed that the adsorption capacity of B by these soils was low with an average adsorption maxima (b) of 16.62 μg g^?1 and bonding energy constant ( K ) of 0.09 mL μg^?1 making soil B susceptible to leaching. The Mango leaf N status was in excess range, which aggravated B deficiency through growth dilution. A significant negative correlation was observed between leaf B and leaf N (statistically significant at 1% level (p=0.01)). The free Al status of the soils was found to be fairly high, and its detrimental effect on root growth was observed which led to inefficient absorption of limited soil B by roots. The climatic conditions of Konkan like high humidity, high temperature and long sunshine hours also favored widespread incidence of B deficiency, low yield and poor quality. The response of Mango cv Alphonso to the B application was found to be more in foliar than in soil application.