| The field experiments were conducted from 2002 to 2004 at the Agricultural Experimental Station of Northwest A&F University,Yangling,Shaanxi Province,China.The genotypes(XY6, S229 and RB6) with lower canopy temperature were named as cold type wheat(CTW) and those(NR9405 and 9430) with higher canopy temperature were named as warm type wheat(WTW).Each genotype was treated with four fertilization modes: CK(no fertilizer),P fertilization(176.25 kg P2O5/hm2),N fertilization(237.0 kg N/hm2),and NP fertilization(176.25 kg P2O5/hm2+237.0 kg N/hm2).The results showed that under no fertilizer condition,there was no significant difference between the yield components of CTW and those of WTW,but under fertilization conditions,the increase rate of effective ears per unit area,grain number per ear,1000-grains weight and yields of CTW were all higher than those of WTW;The CTW genotypes presented a more considerable response to fertilization than the WTW genotypes,and the yield of CTW genotypes was increased significantly by fertilization;The agronomic use efficiency of N was significantly higher than that of P. |