Spring wheat cv. Opal grown on heavy clay soil was given 0-120 kg N/ha and 0 or 2.4 kg CCC/ha. CCC increased yields at the 2 highest levels of N, the only treatments in which there was some lodging in the control plots. CCC at 3 kg/ha improved lodging resistance of winter wheat in 8 trials out of 9 at different sites [but see also F.C.A. 19: 70]. In a trial with winter wheat cv. Cleo given 0-120 kg N/ha, lodging occurred in all treatments not given CCC. Treatment with CCC at 3 kg/ha prevented lodging in plots given 0 and 30 kg N/ha and reduced it where more N was applied; the yield increases obtained, 10-15 kg grain/are, were mostly due to a 20% increase in number of grains. CCC applied at the boot stage discoloured the flag leaf and sharply decreased the grain yield. In a trial with winter wheat cv. Stella given 0-240 kg N/ha, lodging did not occur until late July, and 5 kg CCC/ha applied at Feekes stage 3 [F.C.A. 8: 876] gave only slight increases in yield though it did increase the number of grains by 2-3%. In a trial with 5 varieties of spring wheat given 80 and 200 kg N/ha, 20 kg CCC/ha applied at stage 3 was less effective than 5 kg/ha applied at stage 6. [See also F.C.A. 19: 1377, 2006]-R.B. (Abstract retrieved from CAB Abstracts by CABI’s permission)