Critical Periods for Irrigation of Vegetable Crops

• Asparagus
  Critical Period: Adequate time needed for spear growth, most critical is fern growth
• Broccoli
  Critical Period: During transplant, flower-bud production
• Cabbage
  Critical Period: During transplant, head development
• Carrot
  Critical Period: During root enlargement
• Cauliflower
  Critical Period: During transplant, curd development
• Cucumber
  Critical Period: During pollination and fruit enlargement
• Eggplant
  Critical Period: During transplant, flower, and fruit development
• Lettuce
  Critical Period: Throughout growth
• Lima Bean
  Critical Period: At blossom and pod enlargement
• Muskmelon
  Critical Period: During pollination and fruit enlargement
• Onion
  Critical Period: At planting, and during bulb enlargement
• Pea
  Critical Period: During pod development
• Pepper
  Critical Period: During fruit development
• Potato
  Critical Period: During tuber development
• Rhubarb
  Critical Period: During petiole formation for harvest
• Snap Bean
  Critical Period: During blossom and pod enlargement
• Spinach
  Critical Period: Throughout growth
• Sweet Corn
  Critical Period: During silking and tasseling, and ear development
• Sweet Potato
  Critical Period: When slips are set in the field
• Tomato
  Critical Period: During transplant, early flowering, fruit set, and enlargement
• Turnip
  Critical Period: During root enlargement
• Watermelon
  Critical Period: During pollination, fruit enlargement

This chart by Bill Lamont appeared in The Vegetable Gazette, Volume 3, Number 7, June 1999.