Nitrogen Accumulation and Translocation in Corn Genotypes Following Silking 1

The potential for improvement of N utilization in corn ( Zea mays L.) can depend on the existence of genotypic differences. Accordingly studies were conducted to determine if N translocation from the leaves and stalk to the ear during the period immediately following silking depended on the genotype. In 1970, the N concentration of individual leaf blades, stalk, and developing ears of four inbreds was determined at the silking stage and 14 and 28 days after silking. In a similar experiment in 1971, using bulked leaf blade samples, three of the inbreds plus their F 1 hybrids were analyzed for N at silking and 24 days after silking. In 1970, the apparent translocation of N from individual leaf blades differed considerably depending on the inbred Significant differences in N concentration in either the stalks or developing ears occurred among genotypes in 1970 and 1971. Appreciable differences were found in the apparent propensity of the inbreds to translocate N to the developing ear. In 1970, apparent N translocation during the 14 to 28 day period was greater than during the first 14 days following silking. The inbreds differed between years with respect to apparent N translocation suggesting a genotype ✕ environment interaction. The N accumulation rate following silking was substantially greater in one of the three F 1 hybrids than in the parent inbreds. Thus there appears to be some potential for the screening and development of hybrids capable of accumulating a relatively large quantity of N or using N more efficiently through translocation from various plant parts.