Zinc- Boron Interaction Effects on Yield, Yield Components and Chemical Composition of Wheat.
S. M. Hosseini, Eghlid Agricultural Research Station,Fars Province, Eghlid, Iran
A greenhouse experiment was conducted to study the zinc (Zn)- boron(B)interaction effect on yield, yield components and chemical composition of wheat(Triticum aestivum L. ) in a calcareous soil. Treatments consisted of seven B levels (0, 2.5, 5, 10, 20, 40, and 80 mg kg-1 as boric acid), three rates of Zn (0, 5, and 10 mg kg-1 soil) and two sources (ZnSO4 and ZnO) arranged in factorial manner in completely randomized design with three replicates. Although, Zn treatment had no significant effects on wheat growth, it alleviated the supressing influences of excess B. Boron application, greater of to 5 mg and higher than 2.5 mg kg-1 soil decreased grain and straw yields. The results show that straw was more sensitive to excess B than the grain. Zinc supply increased panicles especially in presence of 20 mg B kg-1 soil , while 80 mg B kg-1 soil reduced grain number and 1000 grain weight. Boron addition up to 5 mg B kg-1 soil had no effect on biological yield ,whereas higher levels reduced it. When no Zn was supplied, 40 and 80 mg B kg-1 soil reduced harvest index. Zinc increased panicle number especially in presence of B.In the present study,Zn increased grain Zn concentration and uptake at all B rates. Moreover, Zn reduced grain B concentration while B increased it. Critical B toxicity was 7.3 mg kg-1 grain. The results reported herein show that in soils with high excess B, Zn application may reduce the adverse effects of B toxicity and consequently increased the plant performance.