Effect of potassium fertilization on recovering drought hazards on sugar beet cultivars at late season [electronic resource].

Includes references.

Two field experiments were carried out dUring 2003 I 2004 and 2004/2005 growing seasons at Sakha Agric. Res. Station, Kafr EI-5heikh Governorate to study yield and quality characters and some water relations of two sugar beet cultivars; Mezanopoly and Top as affected by three irrigation regime treatments W, full irrigation which received planting plus seven irrigations, W, Withholding one irrigation and w, withholding two irrigations at late season and three levels of potassium fertilization 24, 48 and 72 Kg K₂O Ifed. It aimed at maximizing sugar beet production and water use efficiency. The experiments were conducted in split-split plot design, with four replicates. The observed results can be summarized as follows; Water consumptive use was the highest with the treatment under full irrigation regime, where it was 63.99 and 66.92 em in 2004 and 2005. While it was the lowest with the W, treatment, 51.34, and 53.35 em in 2004 and 2005. The daily water consumptive use gradually increased to reach its maximum at Apr. 0.53 and 0.55 cmlday in 2004 and 2005 which was obtained with irrigation treatments of W, and W,. The highest values of W.U.E. for root yield 9.56 and (9.37 kg root beet! m' water in 2004 and 2005) were obtained with Top cultivar under irrigation treatment W, and applying of 48 kg K₂O/fed and W.U.E. for gross sugar yield (1.16 and 1.30 kg sugar 1m' water in 2004 and 2005) was found with Top cultivar under irrigation treatment W, and using 48 Kg K₂O Ifed. The highest values of root yield; 60.67 and 62.18 tonlha in 2004 and 2005 were obtained with Top cuitivar under irrigation treatment W, and adding 24 kg K₂O/fed. The highest values of sucrose 15.25 and 16.75 % in 2004 and 2005 and the highest values of Purity % (66.69 and 68.20 % in 2004 and 2005) were obtained with Mezano-poly variety under irrigation treatment W, and 57 Kg K₂O/ha. The greatest gross sugar yield; 7.57 and 8.56 tonlha in 2004 and 2005 was obtained with Mezanopoly cultlvar under irrigation treatment W, and adding 24 Kg K₂o I fed. in the two seasons. The highest values of white sugar yield (10.16 and 11.66 % in 2004 and 2005) were obtained with Mezano-poly cultivar under full irrigation and using 24 Kg K₂O /fed. The data indicated that optimum potassium decreased the hazards effects of drought on sugar beet crop at late growing season under the field studied conditions.

Summary in Arabic.

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