Effect of Irrigation Intervals, Antitranspirants, Compost and Humic Acid on Growth and Yield of Sweet Potato

A filed experiment was carried out during two summer successive seasons of 2016and 2017 at the Experimental Farm, El-Gemmeiza, Agric Res. Station, ARC, Gharbya Governorate (MiddleDelta) Egypt, to study the effect of irrigation intervals, antitranspirant agents, soil amendments andtheir interactions on growth, productivity and tuber root quality of sweet potato (Buregard cv.) underNile Delta zone conditions. The most important findings could be summarized as follows: highervalues of growth traits, except number of branches/plant in 2nd season and shoot fresh weight in the 1stseason, shoot N, P and total leaves chlorophyll contents, marketable and total yields, as well averagetuber root weight were obtained due to interaction between irrigating at 12 day interval and thecombined of compost + humic acid as a soil amendment. Total carbohydrates, dry matter (DM), N andK percentages were higher due to irrigating at 24- day interval as interacted with the combined ofcompost + humic acid as soil amendment, whereas total carbohydrates (%) was higher with theinteraction of 24- day irrigation interval and compost treatment (3 ton/fad.). After harvest, higheravailable N, P and K besides pH and EC values were obtained under soil amendment of compost+humic acid as interacted with either 12 or 24- day irrigation regimes, however, differences wereinsignificant.