12 | Unit 1.5
Irrigation
- Stage of development and crop natural history
a) “Water-loving” crops (e.g., celery) demand less fluctuation in soil moisture levels
b) Drought-tolerant crops (e.g., tomato varieties, winter squash varieties, Amaranth, etc.)
may require little or no irrigation
c) Maturation period: Prior to harvest, many crops (e.g., onions and garlic) require a gradual
reduction in irrigation to encourage maturation.
H. environmental factors influencing the type of irrigation Used
- climate and incidence of plant pathogens
Overhead irrigation may encourage the growth and spread of certain plant pathogens on
crops in certain climates (e.g., Phytopthora spp. on melons, cucumber, onions, peppers, and
tomatoes along coastal california).
i. irrigation delivery systems
- Sprinklers
a) Micro-sprinklers
i. cost
ii. Efficiency
iii. Application uniformity
iv. Design considerations and infrastructure requirements
b) Hand-moved aluminum pipe with impact heads
i. cost
ii. Efficiency
iii. Application uniformity
iv. Design considerations and infrastructure requirements
- Drip irrigation
a) In-line emitters
b) t-tape
c) Header design
d) Management
i. Filtration
ii. Pressure regulation
iii. Flushing
iv. Fertigation
Student’s Lecture Outline