ضریب تسهیم مواد فتوسنتزی و عملکرد پنبه (.Gossypium hirsutum L) تحت تأثیر محلول‌پاشی پتاسیم در شرایط تنش شوری

In order to investigate the effect of saline irrigation water and potassium spraying treatments on the yield and photosynthetic assimilate partitioning coefficient, a study was conducted in 2014 in the form of split factorial experiment in a randomized complete block design with four replications at Rudasht Salinity and Drainage Research station in Isfahan, central Iran. Irrigation water treatments with salinity of 4, 8 and 12 dS m-1 were the main plots and a factorial of three genotypes (Mutant LM 1673, Mutant LM 1303 and Shayan) with 3 levels of potassium sulfate (2, 4 and 6 kg 1000 L-1 water ha-1) and control (Spraying with water) formed the subplots. The results showed that the effect of salinity treatment on lint yield, lint percent and allocation of dry matter to plant organs was statistically significant. Increasing salinity from 4 to 8 and 12 dS m-1 reduced the lint yield by19.6% and 43.6%, and also reduced lint percent by 5% and 7.3%, respectively. The lint yield of the mutant LM-1303 at 3 levels of salinity of 4, 8 and 12 dS m-1 was 3918, 2990 and 2315 kg ha-1, respectively, and in this respect, a significant superiority was observed compared with the other two genotypes. Spraying with potassium sulfate at concentrations of 2, 4, 6 and 6 per mil increased yield by 20.5%, 31% and 28%, respectively, compared to control treatment. In general, mutant LM-1303 had potential for the successful production under salt stress conditions in the region, and potassium sulfate spraying had a positive effect on the lint yield only under non-stress conditions.