Master Thesis      [Total: 1 ]


Mahmoud Mohamed Ali Ebid, 2008


ABSTRACT Mahmoud Hamdy Mohamed Ebid. Performance and Stability of Some Sugarcane Clones for Earliness, Yield and Yield Components. Unpublished MS.c. Thesis Department of Agronomy, Faculty of Agriculture, Ain Shams University, 2008. The present investigation was carried out under Upper Egypt conditions at two locations, i.e. El-Mataana Agricultural Research Station, Qena Governorate and Shandweel Agricultural Research Station, Sohag Governorate during three successive years started in 2003/04 to evaluate the performance and stability for earliness, yield and yield components of six sugarcane genotypes (clones), viz. G.84-47, G.98-28, G.98-87, G.99-165 and Phil.8013 along with the commercial variety G.T.54-9 as a check variety. The tested genotypes were grown as plant and first ratoon cane crops, and harvested at ages of 11 and 12 months. The experiments were laid out in a split plot design with three replications at each location. The two harvest ages were allocated in the main plots, while the six sugarcane genotypes were randomly distributed in the subplots. The obtained results showed that sugarcane genotypes varied significantly in most of the studied vegetative and quality characters as well as cane and sugar yields in the plant and first ratoon cane crops. In both plant and first ratoon cane crops, G.98-28 genotype had the highest stalk weight, while Phil.8013 gave the highest values of number of plants/m2, cane and sugar yields. Meanwhile, G.84-47 recorded the highest values of sucrose and sugar recovery percentages. Location effect had a significant influence on all studied traits. Growing sugarcane at El-Mataana gave significantly higher values of stalk diameter and stalk weight as well as cane and sugar yields than Shandweel, while at Shandaweel, the number of plants/m2 was higher than El-Mataana, for the plant cane and its first ratoon crops. Also, year effect was significant for all traits. Harvesting sugarcane grown as a plant or first ratoon crop at age of 12 months gave the highest values of all studied characters except plant height as compared to age of 11 months. The commercial variety G.T.54-9 grown as a plant cane crop was superior significantly than all evaluated genotypes in sugar yield when it was planted at Shandweel in the second year and harvested at age of 12 months. Whereas, Phil.8013 genotype grown as a first ratoon crop in the growing season 2004/05 at the same location and same harvest age gave the highest sugar yield. In the first ratoon crop, there was no significant difference between Phil.8013 and G.T.54-9 in sugar yield at El-Mataana in the growing season 2005/06 when they were harvested at 12 months. Results of maturity of genotypes revealed that, the four genotypes i.e G.84-47, G.98-28, G.98-87 and G.T.54-9 were more mature than the two other genotypes, G.99-165 and Phil.8013 in plant cane crop. While, in the first ratoon crop the two genotypes Phil.8013 and G.98-28 were earlier maturing than the genotype G.99-165 and take the same trend in both two harvest ages, but the rest genotypes differed from one harvest age to another. The early maturing genotypes did not show as wide differences between segments as the late maturing genotypes. Results of stability analysis revealed that the promising sugarcane genotype Phil.8013 gave higher cane and sugar yields than the grand mean and its regression coefficient was close to unity. This genotype was considered the best in terms of adaptation to all environments with low deviation from regression value, indicating that it was the best stable genotype under study. Meanwhile, the commercial variety G.T.54-9 was suitable for favorable environments due to its regression coefficient greater than unity, above mean cane and sugar yields and high deviation from regression value. Results also showed that sugar yield exhibited positive and significant correlations with all studied traits with few exceptions, i.e. Brix reading in plant cane crop and each of plant height, number of internodes and Brix reading in the first ratoon crop. These previous traits did not show appreciable relationships with sugar yield. While, cane yield showed positive and significant correlations with each of stalk weight and number of plants/m2 in both plant cane and its first ratoon crops. Furthermore, cane yield had a positive correlation with each of stalk diameter and purity (%) in plant cane crop. From path coefficient analysis of both plant cane and its first ratoon crops, it could be concluded that the selection for heavy stalk was the more advisable for plant breeder to predict high sugar yield. Selection for high number of plants/m2 came in the second rank in degree of importance. These two components had the highest direct, indirect and total effects on yield variation, and significantly correlated with sugar yield. Also, both direct effect of sucrose percentage and indirect effect for number of plants/m2 via stalk weight were about equal in magnitude in both plant cane and its first ratoon crops. Key words: Sugarcane, Saccharum spp., Maturity, Locations, Correlation and path coefficient, G x E interaction, Stability parameters, Yield and Yield components, Juice quality