Early response of a tall, one-, two- and three-gene dwarf wheat varieties to increasing levels of nitrogen

Abstract

Summary The fertilizer-N tolerance during germination and early growth of C 306, Sonalika, Kalyan Sona and U.P. 301—tall, one-, two- and three-gene dwarf wheat varieties respectively, have been determined. On equal N-basis, U.P. 301 (3-gene dwarf) well tolerated NH 4 Cl (up to 0.5% N, w/v) and C 306 (tall wheat) tolerated (NH 4 ) 2 SO 4 more than any other variety during germination. Except ammonium sulphate the remaining three forms of the fertilizers were less tolerated by the tall Indian wheat as against the dwarf Mexican wheat varieties. In general, the dwarf Mexican wheats tolerated higher doses of ammonium nitrate and ammonium sulphate nitrate and were susceptible to chloride in comparison to the tall Indian wheat variety. The inhibitory effect of different fertilizers on shoot and root elongation was in the order NH 4 NO 3 (NH 4 ) 2 SO 4 . NH 4 NO 3 (NH 4 ) 2 SO 4 NH 4 Cl which is in strict proportionality of the osmotic pressure developed. Germination seems to be more affected by ionic whereas elongation by osmotic effects and the tolerance limits for germination and shoot or root elongation are different.