Resumo

HERNANDEZ CORDOVA, Naivy  e  SOTO CARRENO, Francisco. Determination efficiency index in crops of maize and sorghum established in different planting dates and its influence on performance. cultrop [online]. 2013, vol.34, n.2, pp.24-29. ISSN 0258-5936.

In order to determine the influence of different planting dates on some indices of efficiency in maize and sorghum and their influence on performance, this study was developed at the National Institute of Agricultural Sciences, studied three planting dates: November-2008, June-2009 and July-2009, using a density of 50,000 plants.ha^-1, for maize and sorghum cultivation used a dose of 15 kg.ha^-1. Destructive samplings were performed every 15 days of emerged plants until harvest, we determined the total dry mass of the aerial and the leaf area index (LAI), adjusting to an exponential function of the second degree polynomial, where «x» was the day after emergence and «y» the variable in question. From the regression equations were calculated leaf area duration (DAF), we also calculated the efficiency of radiation, the sum of effective temperature and performance, where there was little variation between sowing dates on the temperature accumulated in both cultures obtained and that these differences could be given due to differences in the behavior of the radiation and the temperature during the cultivation cycle, thus obtaining a greater efficiency in the use of radiation and persistence leaf area, which leads to a greater accumulation of biomass at times close to physiological maturity and therefore higher yields.

Palavras-chave : maize; sorghum; planting dates; performance; efficiency ratios.

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