YIELD AND QUALITY OF STUBBLE CANE AS AFFECTED BY IRRIGATION, NITROGEN FERTILIZATION AND VARIETIES

The present work was conducted at El-Mattana Research Station (Upper Egypt) in the two successive seasons of 1996/97 (the 1st ra­toon and 1997/98 (the 2nd ratoon) to evaluate three sugar cane varie­ties (G.T. 54-9, F.153 and G.74-96) grown under two irrigation systems (drip and furrow irrigation) and fertilized with three nitrogen levels (172.5, 207 and 242.5 kg N/fed). The obtained results showed that stalk height and cane yield were significantly affected by irrigation sys­tems in the 1st and 2nd ratoon crops. Sugar yield was significantly af­fected by irrigation systems in the 2nd ratoon only. lrrgation systems failed to reach the level of significance in their effect on sugar recovery %, juice purity %. Sugarcane variety &T. 54-9 attained a significant su­periority in stalk height, stalk diameter, cane and sugar yields over F.153 and G.74-96 varieties. Sugar recovery and purity percentages were not affected by the tested varieties. There was a significant and gradual increase in stalk height, stalk diameter, cane and sugar yields as N levels were increased up to 241.5 kg N/fed for both ratoons. Sugar recovery % and purity % were statistically and negatively affected by in­creasing N level in the 2nd ratoon only.