Effect of preceding crops, nitrogen and potassium fertilization on sugar beet productivity [electronic resource].

Includes reference.

Two field experiments were carried out at Zarzoura Experimental Station during-2005/2006 and 2006/2007 seasonsto investigate the effect of three preceding summer crops (soybean, maize and cotton) and four different levels of nitrogen fertilization (0, 25, 50 and 75 kg N/ fed) and three different levels of potassium fertilization (0, 24 and 48 kg K2O / fed) on sugar beet prodnctivity cv Kawemeira. The results of the experiments could be summarized as follows: The preceding crops had significantly effect no plant dry weight, root diameter, rootweight, top, biological and sugar yields, sucrose% and T.S.S % in both seasons, while leaf area, leaf area index, number of leavesl plant, root length,and root yield were significantly in one season out.The highest values of all studied characters were taken after soybean while the lowest values were taken after cotton in both seasons. Nitrogen levels had significantly effect on all stndied characters in the two seasons. Increasing N level from zero to 75 kg N/fed increased significantly all characters in both Seasons The highest meanswere. taken. at 75 kg N/fed while, the lowest meanswere.taken atcheck treatment (zero kg N/fed). Potassium levels had significantly effect on all studied characters in the IS and 2nd season. The highest means were recorded at 48 kg K2 O/ fed. While the lowest means were taken from the control treatment Data indicated that root length, root diameter, root weight, root, top, biological and Sugar yields a swell as sucrose % were significantly differed by the interactions between preceding crops x N levels, preceding crops x K . levels and N levels x K levels, The highestvalues were taken after soybean x 75 kg NI fed, soybean x 48 kg K20 /fed and 75 kg N/fed x 48 kg K20 / fed respectively. Data also cleared that, root weight, root, top, biological and sugar yields and sucrose % were significantly affected by the interaction between preceding crops x N x K levels. The highest values of all mentioned characters sugar beet after soybean preceding crop and fertilized with 75 kg N/ fed and 48 kgK20 /fed during the two studied seasons . It could be concluded that underthe conditions of the experiment.

Summary in Arabic.

1