Effects of transplanting date of onion set and transplant on earliness and some characteristics of onion populations in Khuzestan province

This experiment was conducted to study the effect of transplanting date of onion set and transplant on earliness of onionpopulationsin Khuzestan province at Behbahan Agriculture Research Station in Khuzestan province and farm of Baghe-e- malek region within one year (2013-14). Experiment was performed in split factorial based on RCBD with three replications. Main plot consisted of propagule types: transplant and onion set. Sub plot consisted of combination of three transplanting dates (23th September, 7th and 23th October) and four population (Behbahan bred onion, Ramhormoz landrace, Primavra and Texas­ early grano cultivars). In order to produce sets, 10-12 grams seeds (of each population) were sown per square meter at Behbahan Agriculture Research Station in late February. For transplants production, seeds were sown in nursery in Baghe-e- melek region on 23th July, 6th and 23th August. Primavera cultivar produced the highest total and marketable yield by both propagules. The total and marketable yield of onion set propagule was higher than transplant propagule at 1% probability level. By postponing transplanting date, from 23th September, bolted plants and double bulbs decreased, but marketable yield increased. According to results, for early production of onion in Khuzestan province planting, Primavera onion set in transplanting date of October 7, with marketable yield of 46.34 t ha-1, is recommended.