مرکز منطقه ای اطلاع رساني علوم و فناوري -

چكيده لاتين :

EFFECT OF IRRIGATION WATER QUANTITY, ANTITRANSPIRANT AND HUMIC ACID ON GROWTH, YIELD, NUTRIENTS CONTENT AND WATER USE EFFICIENCY OF POTATO (Solanum tuberosum L.). Vegetable Res. Dept., Hort. Res. Institute, Agric. Res. Center ** Plant Nutrition Dep., Soil, Water and Environment Res. Institute, Agric. Res. Center ABSTRACT The research was conducted during two successive Nili seasons of 2007/2008 and 2008/2009 at private farm near Mansoura city, Dakahlia Governorate, Egypt (+ 7m altitude, 31o 35- latitude and 30o 58- longitude), to investigate the effects of three irrigation water quantities (800, 1600 and 2400 m3/fed.) and three reducing water requirements substances (distilled water as a control treatment, Kaolin as antitranspirant, and humic acid) as well as their interactions on growth, yield, nutrients content and water use efficiency of potato cv. Cara. The experimental design was a split plot, where water quantity was in the main plots, substances to minimize water requirements allocated in the sub plots with three replications. The most important finding could be summarized as follows: § Increasing irrigation water quantity from 800 to 2400 m3/fed increased potato growth characters of both seasons. Humic acid and Kaolin led to significant increase in most vegetative growth traits compared to control. Second level of water irrigation (1600 m3/fed) with application of humic acid had the most significant effect of most vegetative growth characters, in both seasons of study. § No significant differences were found in total and marketable tuber yield between 1600 m3 and 2400 m3 per feddan in both seasons. Application of humic acid or Kaolin was significantly increased in total and marketable tuber yield as well as tuber quality compared with the control in both seasons. The maximum value of total tuber yield was obtained when potato plants treated with humic acid under the 2nd level of irrigation (1600 m3/fed) in comparison with other treatments. § The first level of irrigation water quantity (800 m3/fed) and/or Kaolin had significant increases in photosynthetic pigments. On the other hand, increasing water quantity applied to potato plants up to the highest used level (2400 m3/fed) and/or Kaolin significantly enhanced both free and total water (%) in potato leaves in comparison with the other treatments. § Plant analysis revealed that N, P and K content as well as micronutrients increased gradually with increasing water supply to the soil. Humic acid led to increases in macro and micronutrients in comparison with the other treatments, in both seasons of study. § Generally, it could be concluded that humic acid or Kaolin application under water quantity of 1600 m3/fed was the best combination for potato production aimed at maximum water use efficiency in this study. Keywords: Potato, Kaolin, Humic acid, Water requirements and Nutrient content.