How to test foliar nutrients
- Sample and test leaf nutrients annually, during mid-August to October.
- Collect the most recently expanded and matured leaves near terminals. This normally will be 5- to 7-month-old foliage that flushed during spring.
- Compare laboratory test results to recommended nutrient levels.
How to fertilize
- Fertilize if needed, generally during March to November.
- Several nutrient sources are available.
- Nitrogen is the most frequently applied crop nutrient.
- Nutrients are commonly applied during irrigation, such as by chemigation or microinjection.
- When calculating the amount of fertilizer to apply, consider other potential nutrient sources. For example, any nitrogen already present in irrigation water should be credited toward the fertilization rate.