Three Decades of Research on Onion (Allium cepa L.) Cultivation in Southern Regions of Iran: A Review

The onions produced in centeral and northern regions of Iran are consumed in autumn and mid winter, and after that, there is a shortage of onions in the market. This shortage can be eliminated by onion production in mid winter in the southern regions of Iran. Short day, early maturity, tolerance to environmental stresses and high yielding are characters of cultivars, that are recommended for onion production in southern regions of Iran. Although many onion landraces are observed in southern region of Iran, however due to low yielding of these landraces, foreign cultivars such as Texas early grano, Texas early white, Primavera and Saba are cultivated in the most part of these regions. Recommended sowing seed and transplants as well as sets transplanting dates varied from early October to mid September depended on climatic conditions, planting methods, season production and genotypes. Application of Zn-Amino celates (specially methionine-Zn) increased yield, pungency, storability and decreased nitrate accumulation in improved population of Behbahan onion and Primavera cultivar. In intercropping of onion and lettuce as well as fenugreek yield, land equivalent ratio and income equivalent ratio were higher than sole crop. Ramhormoz genotype is relative resistance to thrips. Pendimetalin, Focus, Select, Gallent-Super and Oxyfluorofen herbicides control weeds in onion farms. Resistance inducers can be used as a substitute for fungicide application to control downy mildew in onion. The storability of improved population of Behbahan onion , Texas early grano as well as Seba cultivars are high.