EVALUATION OF YIELD AND QUALITY OF SOME SUGAR BEET VARIETIES UNDER SALINITY CONDITIONS AT PORT-SAID GOVERNORATE, EGYPT

Abstract

Ten imported commercial varieties: BTS-3980, Panther, Athospoly, Oscarpoly, Clavius, Pintea, BTS-8115, Palace, pepite and Carrot, were sown under two different types of soil, saline soil (11.3 dSm -1 ) and the other was non–saline soil (0.8 dSm -1 ) at south Port Said Governorate, Egypt (31° N) and (32° E) during two successive seasons. Sowing date was 15 Sep. in each of the two seasons, 2016/ 2017 and 2017/ 2018 . This investigatiob aim to evaluate the influence of soil salinity stress on root yield and components, b) to identify saline tolerant sugar beet varieties based on salinity tolerance indices (STI), c) study the interrelationships and overlapping among (STI) using spearman rank correlation and biplot graph method, and d) plan appropriate selection strategies for improving both root yield and salt tolerance in sugar beet crop in Egypt. The results indicated that growing sugar beet under salt stress caused reduction in root length, (9.4 and 9.8 cm) root diameter(1.2 and 1.3 cm),frish root weight (252 and the246 g) and yield, (8.24 and 8.11 ton/fed), as compared to nonsalt stress in the 1 st and 2 nd season, respectively. While, salinity reduced potassium, (0.49 and 0.37 meq/100 g beet), Alkalinity(0.84 and 0.76) %, number of harvested roots/fed (3.21 and 3.31 thousand and sugar yield ton/fed. (1.11 and 1.09 ton/fed.) with reductions of %, and compared to non-saline one, respectively. On the contrary, the less saline soil yielded roots with low values of sucrose, extractable sugar %, proline and glycine betaine mg/g. fresh weight with substantial augmentation amounted to (0.84 and 0.91), (0.69 and 0.75%), (1.03 and 1.08) and (1.61 and 1.77) percentages in case of the saline soil in the 1 st and 2 nd season, respectively. Whereas the undesirable excess of (α-amino-N and sodium by meq/100g beet and sugar lost to molasses %) as impurities was (0.44 and 0.43) and (0.76 and 0.74) meq/100g beet, (0.15 and 0.16%) in the 1 st and 2 nd season, respectively. A large array of diversity was observed among the examined varieties. Oscarpoly, Clavius and Athospoly varieties had higher root yield and better stress tolerance indices for salinity than others, therefore can be candidate as the best selectable varieties for salinity tolerance. Meanwhile, BTS-8115 and BTS-3980 varieties had lower yield reduction under stress conditions but they were not classified as stress tolerant varieties for their low yield on the average (low mean production). Key word: Sugar beet varieties, salinity, stress tolerance indices, Spearman rank correlation