In India the effect of a foliar spray of potassium nitrate and calcium nitrate on a paira crop of grasspea (Lathyrus sativus L.), grown in rainfed lowland rice fallows, was studied. Entisol soil, having 0,72% organic carbon, 22 kg available P2O5/ha and 240 kg available K2O/ha with pH 6,2 was used. The experiment was a randomized block design with three replications. The foliar sprays of potassium nitrate and calcium nitrate were given at 3 concentrations, supplied equal amounts of N (as nitrate) in the respective treatments. The single foliar sprays were applied during the 50% flowering stage of the crop. All foliar sprays increased the yield attributes of grasspea (Table 1). The foliar spray of KNO3 at 0,50% increased the seed yield most, by 86% over the unsprayed control, averaged over two cropping seasons (Figure 1).
Table 1. Effect of foliar spray of KNO3 and Ca(NO3)2 on yield attributes and average yield (1998-1999) of grasspea, grown as a paira crop.
Figure 1. The effect of foliar treatments on the seed yield (t/ha) of grasspea in two growing seasons.
Sarkar, R.K. and G.C. Malik. 2001. Effect of foliar spray of potassium nitrate and calcium nitrate on grasspea (Lathyrus sativus L.) grown in rice fallows. Jointly supported by Lathyrus Lathyrism newsletter 2: 47-48.