Foliar fertilization and its effect on plant health
Properly nourished crops with nutrient elements like calcium, potassium or micronutrients will exhibit a higher natural resistance to insect pests and disease organisms than crops which are unsufficient supplied. For instance fruits like apples, peaches, strawberries or table grapes are less sensitive to botrytis or monilia fruit rot if the fruit is enriched with calcium or specific micronutrients.
Foliar nutrition has become an established technique worldwide in all sectors of modern crop production.
Foliar Absorption and Transport Mechanisms.
Fundamental steps of foliar nutrient absorption are as follows:
1. Penetration through the cuticle. The cuticle is the first and most limiting barrier to foliar nutrient uptake.
2. Penetration through the epidermis.
3. Penetration through the epidermal cell wall and the cell membrane.
4. Nutrient uptake into the cells
5. Distribution inside the plant as a function of nutrient mobility.
When Necessary?
Foliar nutrition is particularly necessary during the following conditions:
- Visible and latent nutrient deficiencies
- Unsatisfactory soil pH, which block the nutrient absorption
- Insufficient nutrient distribution within the plant (e.g. Ca, B in fruits)
- Physiological stress conditions
- Unbalanced soil nutrient supply
- Soil oxygen deficiency as a result of soil compaction
- During critical stages with high nutrient demand and unsufficient root absorption
- In order to maintain healthy and fully active foliage
