Effect of 1-MCP On Plant Physiology and Yield of Cotton Plants Under Abiotic Stress Caused by Ethephon.

Many environmental stress factors have been identified to increase square and boll abscission and thus result in reduced cotton yield. Under stress conditions, ethylene is elicited. Ethylene peaks before abscission to promote the formation of the abscission layer and plays a major role in early season square and boll abscission. Thus, it is important to protect a crop from ethylene-induced fruit shed under stress conditions. The objective of this study was to evaluate the ability of 1-methylcyclopropene (1-MCP) to protect cotton plants against abiotic stress caused by ethephon (ethylene promoting effect). Field studies with randomized complete block design with four replications were conducted in 2010 and 2011. Eight treatments consisted of two 1-MCP rates (0 and 10 g ai/ha) in combination of 4 ethephon rates (0, 2, 4, 6 oz/A) were imposed at first flower (FF) stage. 6 oz/A ethephon caused a significant decrease in quantum efficiency, membrane integrity and lint yield. 1-MCP protection effect was best under 4 oz/A ethephon, which suggest that 1-MCP works better under moderate stress condition.