ABSTRACT
The present work was carried out during 2018/2019 (plant cane) and
2019/2020 (first ratoon) at Kom Ombo Agricultural Research Station,
(latitude of 24o 28′ North and longitude of 32o 57′ East at an elevation of 108
m above sea level), Aswan Governorate to find out the optimum drying-off
period (15, 30, 45 and 60 days before harvesting date) for five sugarcane
varieties (G.T.54-9, G.84-47, G.2003-47, G.99-103 and Cu.57-14). A
randomized complete block design, in strip plot arrangement, with three
replications, was used.
The results showed that the two studied factors affected significantly
all studied traits in the virgin cane and its first ratoon crop. The highest
values of sucrose, purity, richness, sugar recovery percentages and sugar
yield/fad were recorded with 30 days drying-off, while the highest values of
millable cane weight and cane yield were obtained, sugarcane was dried-off
for 15 days. The promising variety G.2003-47 showed the superiority over
the other varieties in sucrose, purity, richness, sugar recovery percentages,
and sugar yield, while the highest values of millable cane weight and cane
yield/fad were given by G.99-103.
Under the conditions of the current work, on Kom Ombo, sugarcane
crop irrigation should be withheld for 30 days before harvesting for
maximum sugar yield/fad.