Sugarbeet growth, yield components, quality and nitrogen use efficiency as influenced by sources and rates of nitrogen fertilizer

الملخص EN

Two split trials with four replications were conducted at the Bangar El- Sukar region, Burg El- Arab, Alex.

Governorate, Egypt during 2018/19 and 2019/20 seasons to study the effect of two nitrogen sources fertilizers (ammonium sulphate 20.6% and urea 46% ) with three rates (80, 100 and 120 Kg N/ fed.

) on growth, yield components and quality characters and nitrogen use efficiency of sugarbeet grow on a clay loam soil.

Results showed that significant differences were reported between sources of nitrogen fertilizer in the most plant growth characters, yield components, quality parameters and impurity parameters as well as nitrogen use efficiency (NUE) in the two seasons.

Beet plants fertilized with ammonium sulphate as compared with urea significantly exceeded root and top fresh weight, root length, root diameter, leaf area index and total dry matter accumulation per plant as growth parameters, roots, top, gross sugar and white sugar as yield components, percentage of gross sugar, white sugar, quality index as quality parameters and NUE for yields of roots, gross sugar, white sugar and loss sugar in both seasons, and chlorophyll “a” in first season only.

On contrary, also, ammonium sulphate significantly decreased concentrations of K, Na, α- amino- N as impurities and loss sugar% as compared with urea in both seasons.

Application of different rates of nitrogen fertilizer in the two seasons, significantly affected all tested traits, except loss sugar yield and quality index in the first season only.

Application of 120 Kg N/fed.

rate recorded the highest values of all tested plant characters, photosynthetic contents, yield components, quality parameters and NUE for gross sugar and white sugar yields.

.

In addition, the same nitrogen rate produced the lowest values for all impurity parameters measured (K, Na, α- amino- N and AC), loss sugar percent, NUE for roots and loss sugar yields in the both seasons.

The interaction between sources and rates of nitrogen fertilizer were significant effect on root length and fresh weight/ plant in first season only, root diameter, chlorophyll “b”, gross sugar yield/ fed.

, all quality parameters and NUE for loss sugar yield in the second season only.

However, in the two seasons, roots, top and white sugar yields/ fed.

and all impurities as well as NUE for roots, gross sugar and white sugar yields were significantly affected by the interaction between sources and rates of nitrogen fertilizer.

In general, application ammonium sulphate fertilizer at the rate of 120 Kg N/ fed.

was recommended because it recorded the highest root characterse, chlorophyll "b", most yield components and quality traits as well as NUE for gross sugar and white sugar yields, and the lowest loss sugar yield, loss sugar% , NUE for roots yield and all impurities traits.