Improved corn (Zea mays L.) hybrids are generally developed at relatively high N fertility levels. Previous studies have shown that hybrid populations developed by different selection methods vary in their responsiveness to environments. Because N supply is an important factor of the environment which affects yield a field study was conducted to determine the N response of population hybrids improved by intra (full‐sib family) and inter (reciprocal recurrent) selection methods. The responses of the original population hybrid and the two improved population hybrids to N rates of 56, 168, and 280 kg N/ha were studied on an Aquic Paleudult. The improved populations produced more total dry matter and grain at each N level than did the original hybrid. This was associated with an increase in the ear number per plant as the N rate increased. The N concentration of the improved population hybrids at silking was correlated with ear number per plant. Average N use efficiency (grain per unit of N applied) for the improved population hybrids was greater than for the original hybrid. The higher yield of the reciprocal recurrent selection at 56 and 168 kg N/ha as compared with the full‐sib family selection was associated with a higher average N uptake efficiency.
No takes yet. Share an insight, caveat, or question.
Kamprath et al. (1982) studied this question.