Two field trails were carried out at the Farm of South Valley Development Company, Toshka, (latitude of 22 o .49-N, longitude of 28 o .58-E and an elevation of 188 m above sea level) Aswan Governorate, Upper Egypt in 2014-2015 and 2015-2016 seasons. These trials aimed to find out the optimum harvesting age (180, 195, 210 and 225 days) for five sugar beet varieties four of them are multi-germ varieties namely Misribel, Halawa, Husam, and Habiba and one is mono variety namely Natora. The experimental design was a factorial experiment conducted in a complete randomized block design with three replications. Results indicated that delaying harvesting date up to age 225 days significantly increased root length, root diameter, sucrose, purity, extractable sugar and extractability percentages as well as root and sugar yields/fad. Root contents of impurities (α-amino N, Na and K) were significantly influenced by delaying the harvest age. Results showed that sugar beet varieties differed significantly in root length, root and sugar yields/fad. as well as sucrose, purity, impurities percentages. Under the conditions of Toshka region, the results suggested that harvesting Misribel variety at age of 210 days can be recommended to produce the best quality as well as the highest root and sugar yields/fad.

No abstract

This work was carried out during 2018/2019 and 2019/2020 seasons at Kom-Ombo Agricultural Research Station (latitude of 24 o 28′ N and longitude 32 o 57′ E at an elevation108 m above sea level), Aswan Governorate. to assess juice quality and sugar yield of some sugarcane genotypes as affected by bio, inorganic fertilization rates of potassium and nitrogen. The study included 48 treatments, combinations of four genotypes (G.2006-6, G.2003-49, C.57-14 and G.T.54-9), three K rates (48 kg inorganic K2O per fed, 40 kg inorganic K2O + 400-gram bio K and 34 kg inorganic K2O + 800 gram bio K /fed) and four N rates (210 kg inorganic N, 190 kg inorganic N + 300 gram bio N, 170 kg inorganic N + 600 gram bio N and 150 kg inorganic N + 900 gram bio N/fed). A split-split plot design with three replications was used. Results showed that 4 genotypes significantly differed in all studied traits except sugar yield in 1 st season. Furthermore, K fertilization had a significant influence on some studied traits. Nitrogen levels had a significant effect on all the studied traits in the two seasons except purity%. Generally, supplying sugar cane G006-6 and G.2003-49 genotypes, with 100% of the recommended inorganic potassium rate (48 kg K2O /fed) integrated with 100% of the recommended inorganic N-rate (210 kg/fed), or 70% of the recommended inorganic potassium rate (34 kg K2O + 800 gram bio K /fed) integrated with 70% of the recommended inorganic N-rate (150 kg inorganic N + 900 gram bio N fed), resulted in the highest sugar yield/fed in plant cane and its first ratoon crops, respectively.