Reduction of yield of Vicia faba by foliar fertilization during the seed-filling period

Abstract

Vicia faba, in common with other grain legumes, rarely gives economic yield increases in response to soil application of nitrogenous fertilizer either before sowing or at flowering (McEwen, 1970a, b; Day, Roughley & Witty, 1979). The lack of response was attributed to poor uptake of the applied fertilizer particularly at flowering (Day et al. 1979). Garcia & Hanway (1976), however, increased the yield of soya beans from 3695 to 5225 kg/ha with foliar sprays containing N as urea, P, K and S applied during the seed-filling period. Day et al. (1979) using four foliar sprays of the same composition increased yield of V. faba by 361 kg/ha (8·6%) following the uptake of 15% of the 80 kg N/ha applied. However, Robertson, Hinson & Hammond (1977) reported no yield responses of soya beans with up to five foliar sprays of the same composition and noted that those containing ammonium polyphosphate and KNO3 caused leaf damage that significantly reduced yield.