Abstract

M.I. Masri,B.S.B.Ramadan, A.M.A. El-Shafai and M.S. El-Kady

With increasing concern about declining water resources, it has become mandatory to apply appropriate methods to conserve water and reduce chemical inputs in the field of crop production in line with sustainable agricultural practice. Therefore, two field experiments were conducted at Wadi El-Natrun, Egypt (30°23'19.89˝ N latitude and 30°21'41.06˝ E longitude) during 2011/2012 and 2012/2013 seasons to study the effect of water stress (100%, 75% and 50% of irrigation water requirements), two organic fertilization levels (zero and 5 ton compost/fed) and three nitrogen fertilization rates (60, 90 and 120 kg N/fed) on growth, yield and quality of sugar beet plants grown under conditions of drip and sprinkler irrigation systems. Results revealed that drip irrigated sugar beet plants with 75% of irrigation water requirements (IWR) recorded the highest significant leaf area index, sucrose%, purity% and extractable sugar% in both seasons and white sugar yield in the second season only, while application of sprinkler irrigate at 100% of IWR gave the heaviest root weight, root number, purity %, root yield in both seasons. Applying compost (5 ton/fed) with sprinkler irrigation significantly increased root weight, root number and root yield in the both seasons. Also, application of compost (5 ton/fed) with drip irrigation system increased root yield. Increasing N rate up to 120 kg N/fed significantly increased LAI, individual root weight, root number/fed and impurities percentage as well as root yield (ton/fed) in both seasons and white sugar yield (ton/fed) only in the first season. Excessive N application lowered beet quality in terms of sucrose, purity and extractable sugar percentage in both seasons