Importance of Foliar Nutrient Application
17 Nutrients are required for the growth and development of any plant –
| Carbon | Hydrogen | Oxygen | Nitrogen | Phosphorus | Potassium |
| Calcium | Magnesium | Sulphur | Boron | Zinc | Copper |
| Manganese | Iron | Chloride | Molybdenum | Nickle |
Out of these 17 essential nutrients, 3 nutrients are sourced from air and water –
| Carbon | Hydrogen | Oxygen |
For remaining 14 nutrients soil play a very important role –
| Nitrogen | Phosphorus | Potassium | Calcium | Magnesium | Sulphur |
| Boron | Zinc | Copper | Manganese | Iron | Chloride |
| Molybdenum | Nickle |
These 17 nutrients are therefore divided under 4 categories –
Macro-Nutrients
| Carbon | Hydrogen | Oxygen |
Macro-Nutrients
| Nitrogen | Phosphorus | Potassium |
Secondary-Nutrients
| Calcium | Magnesium | Sulphur |
Micro-Nutrients
| Boron | Zinc | Copper | Manganese |
| Molybdenum | Nickle | Iron | Chloride |
To produce good quality crop and yield these nutrients become very important and soil is the source from where these nutrients can be provided. There is another way to provide the nutrients to your plant is through foliage application. It is a technique where nutrients are applied in liquid form directly on leaves and plants can absorb nutrients through their leaves. Absorption of nutrients takes place through the stomata and through epidermis. Application of nutrients to foliage of the crop as in liquid form is known as “Foliar Sprays”.
Benefits of Foliar Application –
- It helps in rapid correction of nutrient deficiency
- Foliar spraying can be combined with other sprayings like pesticides
- When the soil is deficient in nutrients foliar application is beneficial
- When a quick growth response is desired foliar application can be sprayed
- Foliar spray can be applied in adverse condition
- Foliar spray can also be given when there is not adequate moisture in top soil to absorb the nutrients by plant roots
- Only uses small amounts of fertilizer
- Improved yield and yield quality parameter
Key Factors to be Considered for Foliar Application –
| Time of the Day | Early Morning: Before 10:00 AM Late Evening: After 4:00 PM |
| Temperature | Low Temperature: 18-19 Degree Celsius (Ideal: 21 Degree Celsius) |
| Humidity | Greater than 70% relative humidity |
| Wind Speed | Less than 5 mph |
| Rainfall | After foliar application of fertilizers, minimum 24 hours of rainfall free is required for complete absorption of nutrients by leaves |
Desirable Characteristics of Foliar Fertilizer –
Solubility: Foliar fertilizers should be able to either dissolve or suspended in water and contain an active ingredient chemical compound as salts, chelates or complexes of mineral nutrients.
Molecular Weight / Size: Foliar fertilizer must contain low molecular weight or molecules of smaller size to have higher penetration of leaf cuticle.
Solution pH: Solution pH should be adjusted for better activity of nutrients and to prevent the scorching or burning effects.
Solubility: Water solubility is a key factor for foliar uptake, since absorption will occur only when the applied compound is dissolved in a liquid phase on the plant surface that will subsequently diffuse into the plant organs.