The effects of urea foliar application with different concentrations in different growth stages of winter wheat on yield and grain protein content

In order to study The effects of urea foliar application with different concentrations in different growth stages of winter wheat on yield and grain protein content, an experiment was conducted with four concentration of urea foliar (0, 2.5%, 5% and 7.5% pure nitrogen) in three growth stages (tillering, shooting and grain milky stage) and three additional treatments contains: 1- urea foliar with 7.5% concentration in three growth stages 2- broadcast of urea fertilizer (60 kg/ha) (equal foliar application of 7.5%) in three growth stages (tillering, shooting and grain milky stage) on yield and grain protein percent of furrow wheat, based on randomized block design with three replications on croplands in Ghorveh city, from Oct. in 2005 for three years. The results of combined variance analysis revealed that the wheat yield, yield components and grain quality in different years, were different and it was significant at 1% level. So that, highest grain yield and mean of kernel per spike obtained from first year and highest biological yield, plant height, fertile spike number, panicle length and grain protein percent obtained from second year and also highest harvest index, thousand kernel weight, tiller number and flag leaf nitrogen percent obtained from third year. The results of urea foliar application effects on grain yield, yield components and grain quality showed that, treatments effects often were effective and significant in comparison with check treatment, but yield and yield components affected different, related to different treatments, so that, grain yield, biological yield, harvest index, thousand kernel weight and flag leaf nitrogen mostly were affected by foliar treatment with 5% nitrogen concentration in milky stage (C2S3), whereas, grain protein percent was affected by nitrogen broadcast in tillering, shooting and milky stages [B(S1+S2+S3)], foliar treatment with 2.5% nitrogen concentration in tillering stage (C1S1) and or foliar treatment with 7.5% nitrogen concentration in two stages of tillering and milky stages. In addition to, in most cases, check treatment, was lowest quantity. Therefore to pay attention above cases, the urea foliar application with 5% concentrating of pure nitrogen in grain milky stage was recommended. This treatment, in addition to 38% and 22% increasing yield in comparison with check and urea broadcast respectively, it was caused to providence 75% in urea fertilizer consumption.