Plant growth factors

Plants need certain optimum conditions for its growth and development which are summed up as plant growth factors. These are specific requirements of plant cells. The plant growth factors can be studied under:

• Nutritional plant growth factors
• Environmental plant growth factors

Nutritional plant growth factors: Plants require adequate amount of nutrition for their better growth. The basic nutrients required for plant growth are:

1. Macronutrients
2. Micronutrients
3. Water

Macronutrients: The nutrients which are required by the plants in large quantities are termed as macronutrients. There are six elements in the soil which fall into this category. These are nitrogen, potassium, magnesium, calcium, phosphorus and sulfur.

a) Nitrogen: Nitrogen is essential for growth as it is an important part of all proteins, enzymes and metabolic processes involved in the synthesis and transfer of energy. It is an essential part of chlorophyll involved in photosynthesis. Nitrogen improves the quality of the leaf and the foliage crops and also increases seed and fruit production; thus helping in rapid plant growth.

b) Potassium: Potassium activates enzymes necessary for starch synthesis, photosynthesis, energy metabolism, nitrate reduction and sugar degradation in plants. Potassium plays a vital role in reducing water loss from leaves and increases the ability of the roots to take up water from the soil. Potassium improves winter hardiness, drought tolerance, reduction to diseases.

c) Magnesium: Magnesium is essential for photosynthesis as it is an essential part of chlorophyll in all green plants. It also activates many plant enzymes essential for growth.

d) Calcium: Calcium is an essential part of the structure of cell wall in plants, providing normal transport and retention of other elements and strength in the plants. It also counteracts the effect of organic acids and alkali salts within plants.

e) Phosphorus: Phosphorus is essential for photosynthesis, plant maturation, withstanding stress, rapid growth of roots and encourages blooming. It is also involved in the formation of starches, sugars, oils etc.

f) Sulfur: Sulfur improves growth of roots, seed production and makes the plant resistant to cold. It is essential for protein production in plants. Sulfur also promotes activity and development of vitamins and enzymes and helps in chlorophyll formation.