Sarhad J. Agric. Vol.24, No.4, 2008 GENOTYPIC EVALUATION OF SUGARCANE GENOTYPES FOR RATOONING ABILITY SYED MEHAR ALI SHAH*, HIDAYAT-UR-RAHAMAN*, ZAHID IQBAL*, FIDA MUHAMMAD ABBASSI**, DURRISHAHWAR*, AMJAD ALI***, MOHAMMAD YASIR KHAN* and DAWOOD JAN**** * Department of Plant Breeding and Genetics, NWFP Agricultural University, Peshawar – Pakistan Email: mehrpbg@gmail.com ** Institute of Agricultural Biotechnology and Genetic Resources, National Agricultural Research – Pakistan *** Sugarcane Research Institute, Mardan – Pakistan **** Department of Agricultural Economics, NWFP Agricultural University, Peshawar – Pakistan ABSTRACT Five sugarcane genotypes (Malakand-9, Malakand-10, Malakand-11, Malakand-12 and Malakand-13) along with one check cultivar (CP 77-400) were evaluated for ratooning/stubbling ability. The experiment was planted in randomized complete block design with four replications at the Plant Breeding and Genetics Research Farm, NWFP Agricultural University, Peshawar during 2004-05 crop season. Data were recorded on number of tillers stool -1 , growth rate, stalk thickness, response to diseases i.e. ratoon stunting disease (RSD) and mosaic disease, refractive brix, cane yield, sucrose content and sugar yield. Highly significant (p<0.01) differences among the genotypes were observed for RSD, refractive brix, cane yield, sucrose content and sugar yield whereas variation among the genotypes for growth rate were only of significant (p<0.05) nature. Differences among the genotypes were observed non-significant (p>0.05) for stalk thickness, mosaic disease and number of tillers stool -1 . Cane yield showed significantly positive correlations with refractive brix, sucrose content and sugar yield while it gave significantly negative correlation with RSD. Malakand-9 exhibited superiority among all genotypes for most of the traits and its genetic potential can be exploited in future breeding programs. Key Words: Mosaic disease, Ratooning/Stubbling ability, Ratoon stunting disease, Screening, Sugarcane, Yield traits Citation: Shah, S.M.A., Hidayat-ur-Rehman, Z. Iqbal, F.M. Abbassi, Durrishahwar, A. Ali, M.Y. Khan and D. Jan. 2008. Genotypic evaluation of sugarcane genotypes for rationing ability. 2008. Sarhad J. Agric. 24(4): 613-617. INTRODUCTION Sugarcane (Saccharum officinarum L.) is a giant robust tropical grass native to Asia where it has been grown in gardens for over four thousand years (Poehlman and Borthakur, 1972). The crop is mostly valued for the juices extracted from its stem. Its juice, at the proper stage of maturity, contains sucrose or crystalline sugar. It, thus, serves as a basic raw material for sugar production. Over half of the world’s sugar source is sugarcane crop (Braun, 1994). In ancient times sugarcane was used for chewing and its juice for drinking purpose. In the present times of modern technology, sugar mills extract sugar from sugarcane all over the world. Cane producing countries like Brazil, India, Cuba, Pakistan, USA, Equador, Egypt, Mauritius, Australia, Spain, New Guinea and Philippines (FAOSTAT, 2008) are having sugar producing factories from sugarcane (Sugar Factories of the World, 2008). In Pakistan sugarcane is an important cash crop and the surplus sugar can be exported to other counties to earn foreign exchange. In Pakistan it is planted on area of 0.91 million hectare with cane production of 44.7 million tonnes (MINFAL, 2007). Peshawar valley is one of the most important sugarcane growing tracts of Pakistan, which lies, between 32- 36 ° N latitude with altitude ranging from about 300-350 m. The valley has got extreme type of climatic conditions. Average summer temperature range between 100 and 105 ° F temperature and sometime goes as high as 115 ° F. Frost of high and low intensities is the common feature of winter season. Good ratooning in sugarcane is beneficial for the farming community as its production costs lower than the plant crop. However, during the last few years ratoon crop of sugarcane has shown a declining tendency in yield. Almost all the locally adapted exotic sugarcane genotypes have shown this trend. Genetic variation among