The Effect of Foliar Application of Manganese Sulfate on Some Physiological Characteristics and Grain Yield of Wheat under Different Irrigation Regimes

To study the effects of spraying manganese sulfate on some physiological characteristics and seed yield of tetraploid and hexaploid varieties of wheat under different irrigation regimes a factorial split plot experiment based on completely randomized design with three replications was conducted at the Research Station of Faculty of Agriculture, Islamic Azad University, Tabriz Branch, Iran, in the fall of 2013. Irrigation regimes were considered as main factor in three levels, including irrigation at every 7 days (control), cutting off of irrigation at stem elongation (code 30 scale Zadoks) and cutting off of irrigation at booting stage (code 45 scale Zadoks), manganese sulfate fertilizer as sub factor including not spraying, spraying with 50% and 100% concentrations of recommended rate based on soil analysis (with 0.005 concentration) and sub sub factor in four levels, including two levels of each hexaploid (Pishgam and Alvand) and tetraploid (Cheheldaneh and Saji) wheats. The results showed that irrigation regimes significantly affected translocation of dry matter of flag leaf internode, leaf relative water content, duration and rate of seed filling, leaf proline content, water use efficiency and seed yield. Cutting off of irrigation at both stages and also not spraying of manganese sulfate reduced seed yield, rate and duration of seed filling.Cutting off of irrigation at stem elongation stage reduced leaf relative water content (by 33%) as compared to control treatment. Also, cutting off of irrigation increased praline content of leaf, cutting off of irrigation at stem elongation stage increased amount of leaf proline content from 5.35 to 8.34 micro moles per gram. Irrigation at 7 day intervals increased seed filling duration in comparison of cutting irrigation, by 36 days. The highest water use efficiency (0.0018 kg/m3) with total volume water use (2.4 m3) was achieved with the irrigation at 7 day intervals.