Sugar beet yield and quality characters and water relations under conditions of soil moisture stress and N fertilizer levels [electronic resource].

Includes references.

Two field experiments were carried out at Fayourn Agric. Res., station (Kom Osheem) during 2004/2005 and 2005/2006 seasons. Four inigation treatments, i.e. inigation at 30% (I1), 55% (I2), 80 %(I3) available soil moisture depletion (ASMD) and 65 mm cumulative pan evaporation (I.) were combined with three N fertilization levels, i.e. 50 (N1), 75(N2) and 100(N3,) kg N/ fed in a split- plot design with four replications. The effect ofthese combination treatments on sugar beet yield, yield components and quality cbaraclers and crop water relations were studied .The main results were as follows: I. Root diameter, root weight, total plant weight, root yield/fed, sucrose%, T.S.S%, juice purity% and sugar yield/fed were significantly affected by irrigation treatments and N levels in both seasons, wbereas root length was not affected by differed treatments in the two seasons. 2. Increasing ASMD from 30% to 80% significantly decreased root diameter and weigh, total plant weight, root yield/fed, sucrose% and sugar yield/fed, whereas T.S.S% and juice purity increased . 3. Root yield/fed, yield components. sucrose% and sugar yield/fed. obtained from irrigation at 65mm cumulative pan evaporation (CPE) surpassed those of irrigation at 55% or 80% ASMD in both seasons. 4. Increasing N level from 50 to 75 kg N/fed increased yield components. root yield/fed, sucrose% and sugar yield, whereas T.S.S% and purity% decreased. However, more increase in N level to 100 kg N/fed significantly reduced all yield components, root yield/fed. sucrose% and sugar yield/fed, in both seasons. 5. The highest yield components, root yield (23.0 and 25.16 IIfed), sucrose% (23.52 and 22.81%) and sugar yield (5.41 and 5.73 t/fed) in 200412005 and 2005/2006 seasons, respectively, were resulted from inigation at 30% ASMD and applying 75 kg N/fed. However, iniption at 80% ASMD and applying 100 kg N/fed gave the lowest values in both seasons. 6. Seasonal consumptive use (ETc) averaged 64.09 and 62.41/cm in 2004/2005 and 2005/2006 seasons, respectively. Decreasing ASMD from 80% to 30% and increasing N level from 50 to 100 kg N/fed increased seasonal ETc from 57.71 and 56.86 cm to 68.65 and 66.03 em in two successive seasons.

Summary in Arabic.

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