Effects of different levels and resources of zinc in decreasing boron toxicity on citrus in Hajiabad.

Looking out attentive to Iran location in citrus production in world, it is necessary that done scientific reaserches for increasing in quantity and quality of the product. Hormozgan is citrusian province in our country because climate conditions is suitable for citrus cultivation in over here. Therefor,we must solve problems in way of production the economic product. Excessive of boron in soil and water is one of the problems in this region. Many methods recommended for confrontation with this problem, for example consumption of some nutrients like zinc is one of them. In follow this matter, the present research arranged in a randomized complete blocks design with eight zinc levels that six levels as application in soil (0, 30, 60 and 90 Kg Zn in hectare as zinc sulfate and 15, 30 Kg Zn in hectare as Zn-EDTA) and two levels as foliar spary (3 and 5 in thousand zinc sulfate) on sweet orange. The experiment was done in four blocks (three trees in each plot) in Hajiabad agricultural research station. Plant responses sach as yield, fruit quality and boron concentration in leaf were measured after the end of the experiment. The results indicated that application of zinc sources in different levels decreased boron concentration in leaves of Sweet orangs. Consumption amounts 30, 60 and 90 kg Zn in hectare as sulfate decreased 86.35, 103.20 and 149.40 mg B in Kg in trees leaves, respectively. Not only from among different levels of zinc sulfate but also in regard to zinc chelate and foliar spary, the third consumption level means 90 Kg Zn in hectare casued more decreasing in leaf boron concentration. Application 15 and 30 Kg Zn in hectare as Zn-EDTA decreased 78.35 and 94.06 mg in Kg from boron concentration. Furthermore, foliar spary affected in toxicity decreasing of boron, as amounts 62.41 and 72.79 mg B in Kg, respectively. Use different levels and sources of zinc increased yield in regard to blank.