Kloka spring wheat grown on a sandy-loam soil was given 50, 100, 151 or 201 kg N/ha as fertilizer, was irrigated during drought or not irrigated, and was sprayed with CCC (2-chloroethyltrimethylammonium chloride) or not sprayed. Samples, taken approximately weekly from brairding to heading and less frequently to maturity measured the production of dry matter. The dried samples were analysed for percentage N, P, K, Ca, Mg and Na and the uptakes of these were calculated to measure the effects of treatments on the composition of the crop and the weights of nutrients it contained.
Increasing amounts of fertilizer-N up to 151 kg N/ha increased the maximum weight of straw without irrigation and up to 201 kg N/ha with irrigation; similarly, maximum weights of ears were with 100 kg N/ha without irrigation and 151 kg N/ha with irrigation. The maximum weight of straw was at flowering and of ears at maturity. Irrigation increased yields of straw and ears, more with the two larger than with the two smaller amounts of fertilizer-N. Spraying with CCC decreased the yield of straw, and did not affect the yield of ears.
Increasing amounts of fertilizer-N increased percentage nutrients in the green crop and in the straw, and of N, P and Mg in the ears. Effects of irrigation and spraying with CCC on composition differed between nutrients and between ears and straw, sometimes increasing, sometimes decreasing, and sometimes having no effect, on percentage in dry matter.
Increasing fertilizer-N increased the maximum weight of N, K, Ca and Na in the crop. P and Mg increased with up to 151 kg N/ha, but was no more with 201 kg N/ha. Maximum weight of N, P, Mg and Na was found at or near maturity, of K at heading and of Ca at flowering.