EFFECT OF DELIVERY DELAY ON QUALITY PARAMETERS OF SOME SUGARCANE VARIETIES UNDER DRIP AND SURFACE IRRIGATION

This work was carried out in Upper Egypt at El-Mattana Agricultural Research Station, Qena Governorate in two successive sea­sons (1996/1997 and 1997/1998) to study the effect of delivery de­laying processes on quality parameters of some sugar cane vrieties after cutting. Each trail included the combination between two irrigation sys­tems (drip and furrow) and three sugarcane varieties (G.T. 54-9, F. 153 and G.74-97). The results showed that stalk weight losses and reducing sugar percentages of sugar percentages of sugarcane stalks tended to increases as can stalks delivery delayed up to 7 days after cutting. On the contrary, the exracted juice, sucrose and purity percentages de­creased as the period after cane cutting was prolonged. Weight losses, extracted juice, sucrose and purity percentages were significantly affect­ed by the irrigation systems. The highest quality parameters in terms of sucrose and purity were produced under drip irrigation. Reducing sugar percentage was insignificantly affected by irrigation systems. Varietal difference were signifcant in respect to the studied traits. Sugarcane va­riety G.T. 54-9 recorded highest values of extracted juice, brix and puri­ty percentages over the other two varieties. Curve analysis and partial regression analysis indicated that the effect of delivery depends on the quality parameter. In some cases, it was found to be positive (weight losses% and reducing sugar %) in others, it was found to be negative (Purity% and extracted juice%) while in some cases no clear relation was observed, (sucrose % and brix %). In some cases, interaction was exis­tent i.e weight losses% and reducing sugar for stalks. In other cases in­teraction was not existent i.e extracted juice%, sucrose% and purity. The interaction between irrigation systems and sugarcane varieties did not affecte sucrose percentage significantly in both seasons except in the 6th and 7th days in the first season only.