The effect of different levels of phosphorus fertilizer and different planting density on yield and yield component of Persian shallot (Allium altissimum Regel.)

Allium altissimum Regel. is a perennial species of Alliaceae family whose storage tissue is bulb which grows as a wild plant on different slops of mountainous regions and under the canopy of trees and shrubs in gardens. Due to the unsustainable exploitation of A.altissimum and its possible extinction from natural habitats for food and pharmaceutical industries, conducting researches with regard to A.altissimum domestication, cultivation and mass production are required in order to prevent from the paucity of genetic resources. To achieve this goal, the present study aims to evaluate the effect of phosphorus fertilizer and plant density for A.altissimum which are essential parameters in its domestication. A field factorial experiment based on complete blocks design with tree replications was carried out. Treatments of this study were including density at tree levels (20, 30 and 40 plants per square meter) and phosphorus (superphosphate) at four levels (0, 150, 250 and 350 kg ha-1). The results showed that phosphorus fertilizer enhanced wet and dry bulbs yield, biologic yield, grain yield, height of plant. Furthermore, phosphorus fertilizer significantly increased the harvest index of bulbs. Moreover, interactions plant density decreased wet and dry bulbs yield, biologic yield, grain yield, plant height.