ABSTRACT
The objective of this work was to study the effect of beet post-harvest storage under bare field condition for two, four, six, eight, ten and 12 days (before manufacturing) of beet sowing under four sowing dates i.e. August, September, October and November on root rot diseases, root weight, and chemical composition. Therefore, two field trials were carried out at Tamia district, Al-Fayoum Governorate during 2017/18 and 2018/19 seasons. Harvest was implemented (after 180 days from sowing dates) during mid February, March, April and May as corresponding to each sowing dates.
The obtained results revealed:
No infection observed in beet stored for four days in Aug. and Sep. sowing dates and for two days in Oct. and Nov. followed by gradual infection of root rot up to 12 days. Moreover, October sowing exhibited the highest average root wt., while, the lowest root rot diseases infection, highest TSS, sucrose, impurities (Na, K and α-Amino N), sugar lost to molasses, extracted sugar (recovery) and extractability were of August sowing.   
Delaying beet delivery (storage) to process for two days insignificantly affected the reduction of root wt., however, a continuous delay of beet increased the root wt. loss to reach its maximum values after 12 days. TSS, sucrose, extracted sugar and extractability values were increased with time elapsed up to six days and dropped drastically after that. Similarity, continuous and gradual increase in beet impurities and sugar lost to molasses as time elapsed after harvest up to 12 days.
Further, the negative changes detected in all studied traits and root rot injuries as well with the delayed of beet process after harvest were more pronounce with the delaying of sowing dates (Oct. and Nov.) and harvest during Apr. and May. Whereas, early sowing (Aug. and Sep.) exhibited a vice versa trend.             









58                                                    Egypt. J. of Appl. Sci., 35 (3) 2020                                                    





 



Moreover, increase in root rot disease infection, the reduction in average root wt. and various quality attributes by delaying beet manufacturing led to a shortage in root yield, sucrose percentage delivered to the factory and consequently a decrease in farmer income in addition, difficult in slicing freshness roots and increase in sugar lost to molasses during process.