Study of effects of agroclimatic factors on sugar beet seed production in Ardabil region

To determine the possible effects of climatic parameters on sugarbeet seed yield, the correlation between seed yield and different meteorological parameters during 1955-2002 was determined and the parameters which had significant correlation with seed yield were fitted by multivariate models. To scrutinize the effective climatic factors, the growth period of sugarbeet seed-bearing plants (from early-April to late-July) was divided into fifteen-day intervals during planting-bolting, bolting-blooming, blooming-full bloom, full bloom-maturity and total growth period. Then, simple correlation coefficients of each period with seed yield were estimated and finally multiple regression model was fitted. The results showed that the seed yield significantly correlated with mean temperature during the first half of May (-0.591*) and first half of July (-0.584*), mean sunny hours during the first half of May (-0.544*) and first half of June (-0.550*), total precipitation during the second half of April (0.565*) and first half of June (0.624**) and total received growing degree days (GDDs) during the first half of May (-0.505*) and first half of July (-0.584*). On the other hand, sugarbeet seed yield had significant correlation with total precipitation (0.574*) during the planting-bolting period, sunny hours (-0.511*) during the bolting-blooming period and precipitation (0.526*) during the growth period.