摘要：The current study was conducted to evaluate the effects of folic acid a foliar application at various concentrations and stages on growth,yield attributes,grain quality and yield characteristics of rice plants (Giza 179 variety) under using poor quality water.The experiment was arranged in a randomized complete block design with four replicates.The treatments consisted of control,foliar application of folic acid 100uM once at mid tillering stage,twice at mid tillering + panicle initiation stage,thrice at mid tillering + panicle initiation + mid booting stage,200uM once,twice,thrice and 300uM,once,twice and thrice times at the same previous stages.The exogenous application of folic acid regardless of the application folds and stages has a beneficial effect on the plant growth,rice grain yield and improved rice grain quality.Gradual increase folic acid concentration significantly increased morph-physiological characteristics of rice,yield attributes and grain quality.At low concentration of 100 or 200uM of folic acid,once or twice applications is not sufficient,whereas their benefit was significant when they were applied three times.At high concentration of folic acid 300uM applied twice at mid tillering and panicle initiation is enough,since three times application didn't bring more significant increase.Thereby,foliar spray of folic acid three times at the concentration of 200uM or 300uM twice could be recommended for rice growing under using poor quality of irrigation water in the terms of reuse of drainage water for irrigation.
