Fresh sweet corn yield sensitivity to deficit nitrogen and water conditions

Abstract

ABSTRACT Water and nitrogen (N) are the major limitations for maximizing crop yield. However, there has been no detailed examination of these limitations on fresh kernel yield in sweet corn (Zea mays L.). A two-year field study in Shiraz, Iran, was conducted to document sweet corn response to three soil-water regimes (irrigation to field capacity, and 80% and 60% of this amount) and five N fertilizer amounts (0, 75, 125, 175, and 225 kg N ha−1). Decreasing irrigation to 60% of field capacity resulted in yield decreases. The results showed that increasing N amounts increased fresh kernel yield to a maximum at 175 and 225 kg N ha−1. A highly positive, linear correlation was found between fresh kernel yield and kernel number formed per ear (R2 = 0.94), and also between kernel fresh yield and total crop mass (R2 = 0.88). Harvest index (HI) based on dry kernel weight varied between 0.20 and 0.41 in the two years with the lowest HI occurring in the 0 and 75 kg N ha−1 treatments.