Document Type : Original Article
Physiology Department, Cotton Research Institute, Agricultural Research Center, Giza, Egypt
Cotton sowing date is the main management procedure that controlled on yield and fiber quality. Delaying sowing date exposed cotton plants to high temperature during the whole growing seasons that due to shorter growth period and decrease yield. The experiment was conducted at Sakha Research Station of Plant Physiology Department, Cotton Research Institute, Agricultural Research Center, Kafr El-Sheikh, Egypt. The experiment design was split-plot with three replications, which main plots were included sowing date of early and delayed. The sub-plots were randomly of spraying phosphoric acid (PA) at 3000-6000 ppm and ascorbic acid (ASA) at 200-400 ppm concentrations twice at squaring and flowering stages to cognition the effect of sowing date, foliar applications and their interaction effect on leaves chemical constituents, growth characteristics, yield and fiber properties of Giza 97 cotton cultivar during 2021 and 2022. The results examined that delayed cotton sowing date reduced chemical constituents, growth characteristics and yield components compared to early date. Spraying ASA and PA statically enhanced all studied parameters, which the best means recorded by sprayed ASA (400 ppm) then PA (3000 ppm) compared to untreated plants. The interaction between the two factors significantly improved almost studied parameters, which exogenous ASA (400 ppm) gave the maximum values then PA (3000 ppm) comparing to control plants with both sowing dates. Overall, the positive effects of ASA and PA due to their physiological roles in chlorophyll biosynthesis, enhancing photosynthesis rate and plant productivity.