The influence of plant growth habit on calcium nutrition of groundnut (Arachis hypogaea L.) pods

Abstract

In field experiments in India and Niger runner and bunch groundnut cultivars were compared for their pod distribution pattern and its relevance to the calcium (Ca) supply for pod development. Bunch cultivars produced sixty to eighty percent of their pods within 5 cm of the tap root. Runner cultivars explored a radius of up to 30 cm for pod production and exploited the soil area in a more homogeneous manner than bunch types. The available soil volume per pod was 19 to 27 cm 3 for bunch types and 43 to 46 cm 3 for runner types, varying the potential for Ca competition between pods. Computation of the soil Ca content needed to satisfy pod Ca requirements showed that much higher concentrations were needed for the bunch cultivars than for the runners. No significant differences in Ca content of pods existed between bunch and runner cultivars. However, in the runner cultivars, the Ca content of the more widely dispersed pods in outer zones was greater than that of the more densely populated inner pod zones. Regression analysis of shelling percentage across a range of environments showed that the shelling percentage of runners declined less rapidly than did the shelling percent of bunch types, indicating that runners were more efficient in exploiting Ca at lower soil Ca availability than the bunch types.

Sources of Variation in Shelling Percentage in Peanut Germplasm and Crop Improvement for Calcium Deficiency-Prone Soils1

“…2). This interaction between growth habit and pod volume was highly signifi cant (Table 6) and was probably due to reduced compe tition for Ca in the soil associated with more uniform pod distribution (Hartmond et al, 1994). Although these results are based on a small selection of lines, the results suggest a priority for breeders to use spreading peanut types for solving the problem of Ca deficiency where fertilizer inputs are not possible.…”