تأثير تاريخ كاشت بر عملكرد و برخي از شاخص هاي فيزيولوژيكي رشد چغندرقند

The Influence of Sowing Date on Yield and Physiological Indices Sugar Beet

In order to evaluate the effects of different planting dates on quantitative yield and some physiological indices of sugar beet, an experiment was conducted using a randomized complete block design with four replications and four planting dates including April 9th, April 19th, April 29th and May 9th in Ardabil Agriculture Research station in 2005 growing season. The results showed that the date of planting had significant effect on total dry matter, relative growth rate, leaf area index and crop growth rate. By delaying the sowing date not only the total dry matter decreased but also the time requirement for maturity and maximum total dry matter. Plants of the first sowing date with maximum total dry matter (2008 gr/m2) were significantly better than the latest with maximum total dry matter (1581 gr/m2). The highest crop growth rate (24.5 gr/m" day) was 110 days after germination and the first sowing date. The first sowing date had the highest leaf area index (3.88). Similar results were obtained in root yield and the other growth indices such as relative growth rate and net assimilation rate