Effect of applied nitrogen and phosphorus on the nodulation in groundnut (Arachis hypogaea L.)

Abstract

An experiment was conducted in red loam soils of the farm attached to the Agricultural College Vellayani, with the object of studying the effect of applied nitrogen and phosphorus on the nodulation in groundnut. The levels of nitrogen were 0, 10 and 20 kg/ha and those of phosphorus 0, 25, 50, 75, and 100 kg/ha. The number and dry weight of nodules per plant observed at three stages of 2, 4, and 6, weeks after planting were studied. Application of nitrogen significantly reduced and the phosphorus application significantly increased the mean number and dry - weight of nodules at all the three stages of observation. It was also noticed that both the mean number and dry - weight of nodules have increased from the first stage of observation to the second stage and thereafter decreased in the third stage.