ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 53 Number 4
Effects of applied N, P and K fertilizers on the chemical composition of the ear-leaf of maize (Zea mays L.) in field trials in the Eastern Caribbean
The effects of applied N, P and K fertilizers on the chemical composition of the ear-leaf of maize (Zea mays L.) were examined in 28 fertilizer trials carried out in four islands of the Eastern Caribbean. The data were divided into two groups, viz.: (a) the dry Leeward Islands of Antigua, St Kitts and Montserrat; and (b) the wet island of Dominica. At 16 of the 19 sites in the Leeward Islands, application of N resulted in a significant increase in leaf concentration. In Dominica, the effect of applied phosphate fertilizer on the concentration of leaf P was more pronounced with seven of the nine sites showing a significant response in the P level in the leaf. In all territories, potash applied at the rate of 112 kg K per hectare did not significantly increase leaf K content. Sufficiency ranges for N, P and K in the ear-leaf were 2·10 to 2·96 per cent N, 0·25 to 0·41 per cent P and 1·39 to 2·57 per cent K. Critical values for N, P and K in the Leeward islands were 2·19, 0·25 and 2·17 per cent respectively, while for Dominica, these values were 2·53 0·18 and 2·32 per cent respectively.