Determination Of Optimal Irrigation Intervals In Sugar Beet Seed Production In Ardabil Region

The objective of this study was the determination of optimal irrigation intervals in sugar beet seed production fields and evaluation of irrigation at different growth stages of sugar beet seed bearing plants on seed qualitative and quantitative characteristics. Four treatments including of control(I1)(irrigation at three stages planting, bolting and flowering) and irrigation per 50(I2), 70(I3) and 90(I4)mm evaporation from class A pan was carried out in CRBD at four replications in Ardabil agricultural research station at 2002-3. Applied water amounts in I1, I2, I3 and I4 were 3332, 5121, 4419 and 3693 m3/ha(2002) and 2940, 5397, 5280 and 3327 m3/ha(2003) that used at 3, 7, 5 and 4 times in studied years, respectively. Sugar beet seed bearing plants growth periods was accompanied by 510.3 and 471.7mm evaporation and 156 and 136 mm precipitation at 2002 and 2003, respectively. Results showed that increasing of used water in wet(2002) and dry year(2003) has not significant effect on crude seed yield, but in wet year caused the notable reduction in saleable and standard-viable seed yield and in dry conditions caused that negligible increase in saleable seed yield and significant increase in standard-viable seed yield. The highest standard-viable seed yield(1338.48 kg/ha) were obtained with 5 times irrigation(I3) that higher than control(I1) by 33.6%. Irrigation per 50mm evaporation led to significant decrease in oversize portion of seed lots by 41.45%. Higher precipitation in wet year(156 mm) in comparison of dry year(136 mm) led to significant decrease of unkernel seed rate by 5.28% and increase of seed mechanical viability by 15.75%. In comparison of control(with 11.40% unkernel seed portion), increase of applied water was caused that significant decrease of unkernel seed rate.