| Abstrakt: |
Two field experiments were carried out in Senouris, Fayoum Governorate, Egypt (latitude of 30.82° Nand longitude of 29.40° E) in 2014/2015 and 2015/2016 seasons to find out the optimal sowing date, methanol and boron fertilization levels to get the highest yield and quality of sugar beet. This work included two sowing dates (15th September and 15th October), three foliar concentrations of methanol (0, 10 and 20 %) and three foliar concentrations of boron (0, 0.5 and 1.0 g boric acid "17%B"II). At each sowing date, the nine combinations of methanol and boron levels were randomly distributed in a randomized complete block design with three replications. Thereafter, a combined analysis between the two sowing dates was done. Sugar beet Sara multi-germ variety was sown in both seasons. The results revealed that sugar beet sown earlier on the 15th of September over-passed that planted on 15 October in root length, diameter and fresh weight/plant, leaf area index (LA/), net assimilation rate (NAR), photosynthetic pigments, polyphenol, sucrose%, extractable sugar% (ES), purity% and top, root and sugar yields/fed, while Na, K, a-amino nitrogen, fiber and sugar lost to molasses% (SLM) were decreased. Spraying methanol at 20% and/or boron at 1. 0 g boric acid!/ led to significant increments in root length, diameter and fresh weight/plant, LA/, NAR, photosynthetic pigments, polyphenol%, sucrose%, ES%, purity% as well as top, root and sugar yields/fed, while Na, K and a-amino N contents, fiber% and SLM% were significantly decreased in both seasons. The combination between sowing on 15 September and raising concentration of the sprayed methanol solution to 10 and 20% attained the highest root length, LA/, NAR, chlorophyll "a", carotenoids and yields of top and root compared to sowing on 15 October in both seasons, as well as root fresh weight/plant and cplorophyll "b" in the 1st season only, and sucrose%, ES% and sugar yield/fed in the 2nd one. The interaction between sowing dates and boron significantly affected SLM%, purity%, Na content and root yield, in the 1st season, as well as root length and fresh weight/plant, chlorophyll a, fiber%, a-amino N and top yield/fed, in the 2nd one. Purity%, LA/, NAR and_ po/yphenol were significantly influenced by the interaction between methanol and boron levels in the 1st season, as well as chlorophyll "b", Na and K contents, in both seasons. Based upon the obtained results, sowing sugar beet earlier on the 15th of September, sprayed with 20% methanol and 1. 0 g boric acid// can be recommended to attain the highest root and sugar yields/fed as well as the best juice quality characteristics under conditions of the present work. [ABSTRACT FROM AUTHOR] |
