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Abstract SUMMERY THE EFFECT OF SOME FERTILIZATION ELEMENTS ON THE YIELD AND QUALITY OF SUGAR BEET. ********** Two field experiments were carried out in Sakha Agric. Res. Sta. at Kafr EI-Sheikh during 1994/95 and 1995/96 to study the effects of N, P and K fertilizer levels on growth, yietd and quality of sugar beet. The experiments were laid out in a complete randomized block design with four replications. The German sugar beet cultivar ”Top” was used in both seasons. The soil of the experiments was clay loam with a pH value of 8.30 . Each experiment included 30 treatments which were the combination between: • Five N levels: 0, 25, 50, 75 and 100 Kg N/ fad. • Two P levels: 0 and 15 Kg P2°5/ fad. • Three K levels: 0,24 and 48 Kg ~O/fad. The plot area was 21 square meters containing 6 ridges. Sugar beet seeds were planted in hills 20 cm apart. Sowing date was on November, 9 in the first season and October, 7 in the second one. Harvesting was done after 21a days. Nitrogen was applied in the form of ammonium nitrate (33.5% N), P in the form of calcium superphosphate ( 15.5% P20S)’ and K in the form of potassium SUlphate ( 48% ~O). N fertilizer was applied in three split applications 1/4 at planting, 1/2 before the first irrigation and 1/4 before the second irrigation. P fertilizer was added in one application during seedbed preparation. K fertilizer was added in 121 two equal split doses, the first half before the first irrigation and the second half before the second irrigation. Cultural practices were followed as recommended for the region at appropriate dates. Data on growth characters, top and root yields and their components, sugar yield and technological characters were recorded. The results of the experiment could be summarized as follows: A: Effect of N levels: 1- The increase in N level significantly increased number of leavesl plant, leaf length, leaf width and leaves fresh weight! plant at 160, 185 and 210 days from planting in both seasons. The increase in these character was recorded with every increment in N application and followed a linear pattern showing the vital role of N on these characters. 2- Root length, root diameter, root size, root fresh weight! plant significantly increased with the increase in N level at 160, 185 and 210 days as well as in both seasons. The increase in these characters was linear with the increase in N level showing the important role of N as the most important nutritive element for sugar beet. 3- Root: top ratio of sugar beet per plant significantly reduced with the increase in N level in both seasons as well as throughout the three growth stages. The highest root: top ratio was recorded with the check treatment. 4- The increase in N fertilizer level significantly increased root, top, biological and sugar yields of sugar beet in both seasons. Each increment in N level significantly induced an increase in root, top, 122 sugar and biological yields. The highest yields were obtained at the highest N level. The results revealed that applying 100 Kg NI fad seems to be the economical N level for producing maximum root and sugar yields. 5- The response of harvest index to N level was quite different in the two experimental seasons. The highest harvest index was achieved at 75 Kg NI fad in the first season and at 25 Kg NI fad in the second one. 6- The application of N at 25 and 50 Kgl fad favourably affected T.S.S.% and sucrose” in both seasons showing considerable increase in these traits. On the other hand, increasing N level to 100 Kgl fad markedly reduced T.S.S.% and sucrose’i in both seasons indicating the negative effect of the highest N level on the quality characters of sugar beet juice. 7_ Purity0/owas markedly reduced with the increase in N level in both seasons. The percentages of alpha- amino N, K and Na were slightly increased with the increase in N level in both seasons. But the reduction in quality due to the increase in N level did not reach the level of signifrcance. 8- Sugar recovery% significantly increasedwith the increase in N level. The highest recovery”/owas recorded by applying 50 Kg NI fad in both seasons. 123 B: Effects of P levels: 1.The application of 15 Kg P20s/ fad favourably affected number of leaves/ plant, leaf length, leaf width and top fresh weightl plant at 160, 185 and 210 days from planting, particularly in the second season where the effect of p. application on all these traits reached the significant level. 2- P application favourably affected root length, root diameter, root fresh weightl plant and root size at 160, 185 and 210 days. In most cases and particularly in the second season, the effect of P application reached the level of significance. 3- Root: top ratio per plant was reduced due to application of 15 Kg P20S/ fad particularly in the second season where this reduction was significant indicating that P application favourably affected top growth more than root growth. 4- P application increased root, top, biological, and sugar yields in both seasons. The effect of P application was significant on root, biological and sugar yields (in 1995/96 season), whereas P effect was not significant on top yield and sugar yield in 1994/95 season. 5- Harvest index was not significantly affected by P application in both seasons. 6- P application increased T.S.S., sucrose, purity and sugar recovery percentages in both seasons. 7. Percentages of impurities including alpha- amino N, K and Na% were not apparently affected by P application. The differences observed in these impurities were negligible and far below the significant level. 124 C: Effect of K levels: 1- The application of K increased significantly number of leaves Iplant, leaf length, leaf width and top fresh weight/plant at 160, 185 and 210 days from planting in both seasons. The highest values of these traits were recorded with the application of 48 Kg K20/fad. 2- The application of K markedly increased root length, root diameter, root size and root fresh weight Iplant at 160, 185 and 210 days from planting in both seasons. The effect of K application on these characters reached the level of signiflC3nce in most cases and the highest values were recorded with the application of 48 kg ~O/fad. 3- K application had no definite and clear effect on root top ratio per plant. The results were illdefined and had no specific trend. 4- The application of K significantly increased root, top, biological and sugar yields of sugar beet in both seasons. The highest values of these characters were recorded at the highest K level. The application of 48 kg ~Olf$d significantly increased root, top , biological and sugar yields by 14.51, 19.39, 14.98 and 19.47% compared with the check treatment in the first season. The corresponding increases in the second season were 5.11, 9.51, 5.82. and 9.34%, respectively. 5- Harvest index was not significantly affected by K application in both seasons. 6- T.5.5., sucrose, purity and sugar recovery percentages were favourably affected by K application in both seasons. Applying K 125 markedly increased these traits and the highest values were recorded at the highest K level. 7_ K% increased due to K application. On the other hand, Na% was slightly reduced due to K fertilization. Also, very slight decreases were observed in alpha- amino N°lo due to K application. 0: Interaction Effects: D.1: N x P Interactions 1- Nitrogen x Phosphorus interaction had significant effect on : _ Number of leaves! plant at 160 and 185 days in the second season . . Leaf length at 185 days and 210 days in the second season . . Leaf width at 185 days and 210 days in the first season. -ToP fresh weight! plant at 160 and 185 days in the second season. -Root length at 185 and 210 days in the first season and at 160, 185 and 210 days in the second season . .Root diameter at 210 days in the second season. -Root fresh weight! plant at 160 and 185 days in the second season. -Root size at 160 and 185 days in the first season and at 185 days in the second one . •Root top ratiof plant at 160 days in the second season. The highest values of all these characters were recorded by The combination of 100 Kg N + 15 Kg P20,j fad. 2- The interaction betWeen N x P had no significant effect on root, top, biological and sugar yields as well as harvest indeX in bOth 126 seasons. However, the highest root, top and biological yields were produced by combining 100 Kg N+ 15 Kg P2°5 1 fad. 3- The interaction between Nand P had significant effect on T.5.5, sucrose and purity percentages in the firsts season. D. II: N x K Interactions: 1- The interaction between Nand K had significant effect on: _ Number of leavesl plant at 160 days in the first season and at 185 days in the second one. _ Leaf \ength at160 days in the first season. _Leaf width at 160 days and 185 days in the first season. -Top fresh weight! plant at 160 days in the first season and at 185 days in the second one . . Root length at 210 days in the second season. _Root freSh weight! plant at 160 days in the first season. The highest values of tnese characters were recorded by combining 100 Kg N + 48 Kg KzOI fad. 2- The interaction between Nand K had no significant effect on root, top, biological and sugar yields as well as harvest index in both seasons. 3- The results showed that root, top, biological and Sugar yields reached their maximum values by combining 100 Kg N + 48 Kg ~O/fad. 4- N x K significantly affected T.5.5.%, purity%, sugar recovery% and Na% in the first season. D: ill: P x K interactions: 127 1- P x K significantly affected: _Number of leavesl plant at 160 days in the first season. _Leaf length at 210 days in the second season. _ Leaf width at 160 days in both seasons and at 185 and 210 days in the second season. _ Top fresh weight! plant at 160 and 185 days in the second season. _Root length at 210 days in the second season. _ Root diameter at 160 days in the first season, and at 210 days in both seasons. _ Root fresh weight! plant at 160 days in the first season, and at 185 days in both seasons. ~ ~ / _ Root size at 160 days in the first season and at 185 days in both seasons. _Root: top ratio/ plant at 210 days in the second season. 2- The highest values of these traits were almost recorded by combining 15 Kg P20S+ 48 Kg K.;.0l fad. 3- Top yield as well as biological yield in the second season were significantly affected by P x K interaction where the highest values were recorded by combining 15 Kg P20S + 48 Kg ~Ol fad, being 5.54 and 32.78 t1 fad, respectively. 4- Purity0/o in the first season was significantly affected by PxK interaction and the greatest purityO/o was 83.490/0 recorded by combining 15 Kg P20S + zero ~Olfad. D. IV: NxPxK Interaction: |