versión ISSN 0258-5936
MAQUEIRA, L. A; PEREZ, S. A y TORRES, W. Growth and productivity of rice varieties CYCLES IN TWO DIFFERENT PLANTING DATES IN THE COLD SEASON IN PALACIOS, Pinar del Rio. cultrop [online]. 2010, vol.31, n.4, pp. 00-00. ISSN 0258-5936.
This work was carried out in the areas from Los Palacios Rice Research Station of INCA, Pinar del Río, using INCA LP-5 and Reforma as short-cycle varieties, besides INCA LP-2 and J-104 as mid-cycle ones, during the dry season of January 2004 and February 2005, on an Ironstone Nodular Gley Hydromorphic soil, with the objective of evaluating the behavior of rice varietal growth and productivity. A direct seeding technology was employed with a pattern of 120 kg.ha-1. Agrotechnical activities followed rice crop technical instructions. A randomized block design with four replications and 25-m2 experimental plots was used. Dry matter of the aerial part of plants (g.m-2) was determined in a 25-m2 frame and samplings were fortnightly performed 25 days after germination until harvest. The absolute growth rate and leaf area index were calculated, besides determining agricultural yields and its main components; all data were processed by means of a single Anova through Duncan´s multiple range test (p<0.05). Considering the results, it should be highlighted that agricultural yield was higher in short-cycle varieties than in the mid-cycle ones, with higher leaf area index values in those varieties. Radiation availability during the reproductive phase at the sowing date of February 2005 was a limiting factor for the varieties to reach top dry matter production and so to achieve higher yields. The best results of INCA LP-5 and Reforma could be related to varietal genetic characteristics, which are recommended for the breeding programs to search for new more productive cultivars.
Palabras llave : Oryza sativa; rice; dry matter; crop yield; growth.