Seed Production of Vegetable, Tuber and Spice Crops (2+1)

Botany

• Onion is the biennial crop and takes two full seasons to produce seeds.
  
• In the first year bulbs are formed and in the second year stalks are developed and produced seeds.
  
• It is a long-day plant. The day length influences bulb onion, but has little effect on induction of seeding.
  
• It appears to be day-nautral for seed production.
  
• It requires cool conditions during early development of the bulb crop and during early growth of seed stalk. Varieties bolt readily between 10 to15° C.
  
• In the early stages of growth, a good supply of moisture is required and temperatures should be fairly cool.
  
• During bulbing, harvesting and curing of seed, fairly high temperatures and low humidity is desirable.
  
• Seed production is widely adapted to temperate and sub-tropical regions.