EFFECT OF PEDUNCLE-PERFUSED NITROGEN, SUCROSE, AND GROWTH-REGULATORS AMINO-ACID-COMPOSITION

Nitrogen (N) or growth regulator application to small grain cereals ne ar anthesis has been demonstrated to alter grain fill and grain yield, the protein yield and nutritional quality may also be modified by the se management factors. The objective of this study was to determine wh ether delivery of N, growth regulator, or sucrose solutions into green house-grown barley (Hordeurn vulgare L, cv. Leger) or wheat (Triticum aestivum L. cv. Katepwa), plants through peduncle perfusion altered th e amino acid composition of the grain. The following treatments were t ested: N (25 and 50 mM), chlormequat (30 mu M), ethephon (15 mu M), N + chlormequat, N + ethephon, detillering + N, sucrose (250 mM), distil led water check, and non-perfused check. Perfusion lasted 30 d beginni ng 5 to 8 d after spike emergence. Addition of N via peduncle perfusio n increased protein concentrations and concentrations of all amino aci ds in both barley and wheat when expressed in terms of grain dry matte r. Protein yield and lysine content were also increased. However, the increase in essential amino acids such as lysine, methionine, threonin e, isoleucine, arginine, and leucine was relatively small, and the pro portions of these amino acids in the grain protein were actually reduc ed. The sucrose treatment only affected wheat, increasing lysine conce ntration and decreasing the total protein concentration. Growth regula tors used in this study did not alter protein yield or amino acid comp osition in either crop.