Response of flame seedless grapes to sulphur and different nitrogen sources and application times under calcareous soil and drainage irrigation water I. soil Ph, growth, yield and leaf chlorophyll and mineral content [electronic resource].

Includes references.

Effect of nitrogen sources The results a 2001 and 2002 seasons indicated that, regardless of nitrogen application times and sulphur rates, the addition of nitrogen as urea or ammonium nitrate to Flame Seedless grapes grown in calcareous soil and irrigated by drainage water increased shoot length, leaf chlorophyll content, yield and petioles N and K content during both seasons and increased petioles Ca content in the first season as compared with ammonium sulphate. The ammonium sulphate and urea applications increased petioles Mn and Zn in the second season as compared With ammonium nitrate that increased petioles Mg during both seasons. Whereas, urea fertilizer increased petioles Ca and decreased the soil pH in the second season as compared With ammonium sulphate and ammonium nitrate. The ammonium sulphate increased petioles Fe in the second season and Mn in the first season, but decreased soil pH during both seasons. The different nitrogen sources did not affect petioles P and Na content, in both seasons, and Fe and Zn in the first season.2. Effect of nitrogen application times Regardless of nitrogen sources and sulphur rates, the application of nitrogen fertilizer at three equal doses to Flame Seedless grapes increased shoot length, yield, leaf chlorophyll content and petioles N, Ca and Mg content Meanwhile, no differences were found between the three times of nitrogen application, during both seasons, on soil pH and petioles P, K, Na, Zn and Mn content.

Summary in Arabic.

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