Molybdenum Requirements of Dry Bean with and without Liming

Abstract

Molybdenum (Mo) is an essential micronutrient for crop plants, and its deficiency has been reported in many parts of the world. Two greenhouse experiments were conducted with the objective to determine Mo requirements of dry bean (Phaseolus vulgaris L.) grown on a Brazilian Oxisol with and without liming. The Mo treatments were 0, 5, 10, 15, and 20 mg kg−1. In one experiment dolomitic lime was added at the rate of 2.5 g per kg of soil before the application of Mo treatments and incubated 5 weeks before sowing. In other experiments, Mo treatments were same as the lime-added experiment but no lime was added. Most of the growth, yield, and yield components were significantly increased with the addition of Mo in both the experiment. Growth, yield, and yield components were increased in a quadratic fashion when Mo was applied in the range of 0 to 20 mg kg−1. Maximum shoot dry weight was obtained with the addition of 17 mg Mo kg−1 in the experiment with Mo rates without lime and 9.69 mg Mo kg−1 in the experiment of Mo rates with lime application. Maximum seed yield was obtained with the application of 10.48 mg Mo kg−1 in the experiment that did not receive lime along with Mo treatments and 10.28 mg Mo kg−1 in the experiment that received lime along with Mo treatments. Similarly, the maximum number of pods per plant was obtained with the addition of 9.33 mg Mo kg−1 in the experiment that did not receive lime and 8.83 mg Mo kg−1 in the experiment that did receive lime. Maximum root length was obtained with the addition of 12.38 Mo kg−1 in the experiment that did not receive lime and 9.75 mg Mo kg−1 in the experiment that received lime. Maximum root dry weight was obtained with the addition of 11.67 mg Mo kg−1 in the experiment that did not receive lime and 9.28 mg Mo in the experiment that received lime. Soil properties determined after harvest of dry bean plants were not influenced significantly with the addition of Mo in the Oxisol under investigation.