Rendimiento del maíz y las epocas de siembra en los LLanos Occidentales de Venezuela

this study was carried out in order to determine the effect of planting date on corn yields at the western plains of venezuela, using the information generated by the technical assistance program of the association of rural producers of the portuguesa state (asoportuguesa), in the cropping season from 2001 to 2003. planting date, farmer name, cultivar name, farm plot and location were registered each year. at harvest time, the yield for each planting date, cultivar, farm plot and location was recorded. there were considered four planting dates, each one consisting of 15 days, starting up the first in the first 15 days of may, when usually the commercial sowing in the region is started. the analysis of the variance was performed for each year, considering a factorial arrange with two factors (seasons and cultivar) and another analysis combined over years, considering a mixed model with tree factors (seasons, cultivar and year). a regression analysis was also computed for all years, in order to determine the effect of planting date on corn yield. corn yield was highly affected by years, cultivars and planting date. we founded a mean reduction of 340 kg ha-1 when it passed from a fortnight to another. we determine that may is the best corn planting date in the western plains of venezuela