Identifying critical limit in soil and plant for determining response of groundnut (Arachis hypogea) to boron application in Madurai soils of Tamil Nadu, India

Abstract

ABSTRACTTo establish critical limit in soils and plant, soil samples were collected from twenty; 12, 5 and 3 soil locations of low, medium and high boron (B) status from Madurai district of Tamil Nadu, India for pot culture experiment. Based on the results of pot culture experiment, the critical limit was determined to be 42.7 mg kg−1 for groundnut plants and 0.39 mg kg−1 in Madurai soils. Groundnut plants were highly responded to B application in soils below the critical limit whereas soils with B greater than 0.51 mg kg−1 did not respond. For the confirmation of pot culture results, a field experiment was conducted with different B treatments comprised of soil and foliar applications and results revealed that the pod yield of groundnut increased with increasing levels of B and the soil application of 20 kg ha−1 as borax has showed significantly higher pod yield in the district.