Journal of Plant Process and Function

To study effects of planting date, phosphate Bio-fertilizer and foliar application of Zinc and Boron on leaf area index, leaf area duration, leaf relative water content, cell membrane stability, quantum efficiency of PSII, leaf proline content and grain yield of bread wheat (Aflak cultivar), an experiment was conducted as split-plot factorial based on randomized complete blocks design with 16 treatments and 3 replications in Ramhormoz city during farming year 2015-2016. The experimental factors were included planting date (November, 21and January, 5) as the main factor, phosphate bio-fertilizer (Barvar 2) in two levels (non-used and using as seed inoculation) as the sub factor and foliar application in four levels (water as a control, Zinc, Boron and combination Zinc + Boron (each 3 lit.h^-1)) as sub-sub factor. Solutions for foliar application were prepared by using Zinc- chelate (7.5%) and Boron (5%). With delay in planting due to terminal heat stress except leaf proline content all traits leaf area index (LAI), leaf area duration (LAD), flag leaf relative water content (FLRWC), cell membrane stability, quantum efficiency of PSII (ΦPSII) and grain yield were decreased significantly. Seed inoculation with phosphate bio-fertilizer reduced harmful effects resulting from delay in planting on above traits. In between the different levels of nutrients foliar application, the combined application of Zinc + Boron<span style="font-family:;" dir="RTL" new="" b="" roman";"="" roman";="" "times="" lotus";=""> as compared to the separate application for each of them was more effective in reducing the harmful effects resulting from delay in planting. But when the seeds were inoculated before planting with phosphate bio-fertilizer, the separate application Zinc element had more influence in improving the traits of LAI, LAD, FLRWC, cell membrane stability, ΦPSII, leaf proline content and increase yield of bread wheat in both optimum and late planting date.