INFLUENCE OF DRIP IRRIGATION RATES AND SOIL IMPROVERS ON THE PERFORMANCE OF SOME SUGAR BEET VARIETIES IN NORTH SINAI

The presented work aims to study the effect of drip irrigation rates and soil conditioners/ improvers on yield and quality of three sugar beet varietiesduring two winter successive seasons 2012/2013 and 2013/2014 under new land conditions of North Sinai Governorate, Egypt. Statistically split-split plot design was used. Irrigation rates had a significant effect on root length, root diameter, sucrose percentage, root and sugar yields in both growing seasons while it had a significant effect on purity percentage in 1^st season only. Irrigation rate of 3000 m³/fad., over passed that of 2500 m³/fad., which recorded the highest values of root diameter, sucrose percentage, purity percentage, root and sugar yields. On the other hand, Irrigation rate of 2500 m³/fad., over passed that of 3000 m³/fad., which recorded the longest root. Moreover, sugar beet varieties had a significant effect on root length, root diameter, sucrose percentage, root and sugar yields in both growing seasons while it had a significant effect on purity percentage in 1^st season only. Marathon variety gave the highest values of root length, root diameter, root and sugar yields. Farida variety gave the highest values of sucrose and purity percentages. Soil improvers had a statistical effect on root diameter, purity percentage, root and sugar yields in both growing seasons while it had a significant effect in 1^st season only on root length and sucrose percentage. Iquet compound was the best soil improver that attained the highest values of the studied traits in both seasons. The 2^nd order interaction of irrigation rate × variety × soil improver statistically affected on root diameter in 1^st season, sucrose and purity percentages in 2^nd season and root length, root and sugar yields inboth seasons. Using 3000 m³/fad., of irrigation rate in combination with Humic acid as soil conditioner for Marathon variety was the best combination that recorded the highest root and sugar yield values (30.58 and 5.99 ton/fad., respectively, as a mean of both seasons). However, using the sameirrigation rate in combination with the same soil conditioner for Farida sugar beet variety attained the highest purity percentage value (96.77%). The combination of 3000 m³/fad., with Iquet for Marathon variety gave the highest root diameter value (26.8 cm) while the same combination with Farida variety recorded the highest sucrose percentage value (20.06%). Thus, the combination of 2500 m³/fad., with Iquet for Marathon variety attained the highest root length (35.3 cm).