273 www.internationalsugarjournal.com INTERNATIONAL SUGAR JOURNAL 2012, VOL. 114, NO. 1360 Introduction Sugarcane is the second most important cash crop of Pakistan after cotton, with a share of 9.96% of major agricultural crops grown in the country (GOP, 2010). Pakistan’s cane acreage is globally the 5th largest and is the 9th biggest global producer of sugar (ISO, 2010). Ratooning is a common and desirable practice. In the state of Punjab, more than 50% of sugarcane cropped is ratooned (Malik, 1997) and its contribution to the total cane production is about 25-30% (Rehman and Ullah, 2008). However, more than 35% of its productivity is lost due to improper attention of the farmers towards ratoons (Malik, 1997). Naturally the productivity of ratoon is 10-30% less than the plant crop of sugarcane. Low yield of ratoon crop is mainly due the low and differential ratooning potential of cultivars and suboptimal crop management. Ratooning is more economical than plant crop, saving 25-30% operational cost along with seed material. A ratoon crop matures prior to plant crop thus ensuring early supply of cane to mills. Under similar conditions sugarcane ratoons have a supplementary advantage of better juice quality and sugar recovery as compared to plant crop of same variety (Yadav, 1991). Late maturing cultivars having good yield are suitable for growing ratoon but early maturing cultivars are poor ratooners. Spring harvested crop gives better ratoon than autumn harvested due to moderate temperature, which is most conducive for stubble sprouting. Ratooning ability of sugarcane genotypes at different harvesting dates 1 Sugarcane Research Institute, Ayub Agriculture Research Institute, 38950, Faisalabad, Pakistan. 2 Department of Agronomy, University of Agriculture, 38000, Faisalabad, Pakistan. * Contact author: Email: naeem_1732@yahoo.com Shahid Bashir, Naeem Fiaz 1* , Abdul Ghaffar 1 and Farhan Khalid 2 abstract In a field experiment during 2007-2009 at the Sugarcane Research Institute, AARI, Faisalabad, Pakistan, plant crops of varieties CP 85-1491, S2001-SP-104, S2002-US-452, S2002-US-628, S2003-US-114 and HSF-240 (cultivar) were harvested on 1st November, 1st December, 1st January, 1st February and 1st March (2007-2008) and the subsequent ratoon crops were harvested in February 2009. Yield parameters (sprouting, millable canes, cane production) were generally highest in the plant crop harvested on 1st February, with the average cane yield of 79.11 t/ha. While the CCS content was lowest crops ratooned in February, the overall sugar yields were still highest from February ratooned crops. S2003-US-114, S2001-SP-104 and S2002-US-452 produced similar cane yields which were significantly higher than the others. Keywords: genotypes, harvesting dates, ratooning ability, sugarcane Capacidad de rebrote de genotipos de caña de azúcar a diferentes momentos de cosecha En un experimento de campo durante 2007-2009 en el Instituto de Investigación de la Caña de Azúcar, AARI, Faisalabad, Pakistán, cultivos de las variedades CP 85-1491, S2001-SP-104, S2002-US-452, S2002-US-628, S2003-US-114 y HSF-240 (cultivar) se cosecharon el 1° de noviembre, 1° de diciembre, 1° de enero, 1° de febrero y 1° de marzo (2007-2008) y los cultivos ulteriores de rebrote se cosecharon en febrero de 2009. Los parámetros de rendimiento (brotado, cañas para molienda, producción de caña) fueron en general mayores en el cultivo cosechado el 1° de febrero, con un rendimiento promedio de caña de 79,11 t/ha. En tanto que el contenido de CSS fue el más bajo en los cultivos rebrotados en febrero, los rendimientos totales de azúcar fueron todavía más altos en los cultivos rebrotados en febrero. S2003-US-114, S2001-SP-104 y S2002-US-452 produjeron rendimientos de caña similares que fueron significativamente mayores que los otros. Capacidade de soca de genótipos de cana de açúcar em datas diferentes de colheita Em um experimento de campo durante 2007-2009 no Instituto de pesquisa da cana, AARI, Faisalabad, Paquistão, culturas de variedades CP 85-1491, S2001-SP-104, S2002-U.S.-452, S2002-U.S.-628, S2003-U.S.-114 e HSF-240 (cultivar) foram colhidas em de novembro, 1º de Dezembro, 1º de Janeiro, 1º de Fevereiro e 1º Março (2007-2008) e as culturas de soca subseqüentes foram colhidas em fevereiro de 2009. Parâmetros de rendimento (broto, canas processáveis, produção de cana) foram geralmente mais elevados em cultura colhidas em 1º de fevereiro, com o rendimento de cana médio de 79.11t/ha. Enquanto o conteúdo de CCS foi menor nas culturas da soca em fevereiro, os rendimentos de açúcar global foram ainda mais altos a partir de culturas de de soca de fevereiro. S2003-U.S.-114, S2001-SP-104 e S2002-U.S.-452 produziram rendimentos similares de cana que eram significativamente mais elevados do que os outros.