Growing Conditions of Potato
The potato (originally from South America), is one of the most important food crops in the world.
400 million tons of potatoes are produced each year when China is the largest producer, holding 25% of world’s production.
The world average yield of potato is 160 cwt per acre (20 ton/ha) and in many developed countries the average is more than 320 cwt per acre. Yields of 600 cwt/acre per acre are achieveable
GROWING CONDITIONS OF POTATO
CLIMATE
Growing potatoes requires cool climate. Potatoes grow best in temprature of 15-20(°C). Nevertheless, it has the ability to adapt to a wide range of climate conditions.
The potato grows best in well-drained soils and pH is optimal between 4.8 to 5.8.
The maximum tolerated EC (salinity threshold) is 1.7 dS / m.
Although sandy soils have clear advantages in mechanization of farming, it requires high amounts of fertilizer. The use of tissue analysis is important as it can warn and prevent nutritional deficiencies.
POTATO NUTRIENT REQUIREMENTS
The Importance of Macronutrients in Potato
Nitrogen: One of the most important nutrients, that is required in relatively high quantities for achieving high yields. Nitrogen is required especially in the initial stage of the vegetative growth.
Excess of nitrogen might cause excessive foliage growth, at the expense of tuber growth.
Under many conditions, nitrate nitrogen is preferred over ammonium nitrogen.
Phosphorus: Encourages root growth and tuber formation. Adequate supply of phosphorus is important in the tuber initiation stage.
Potassium: Potatoes have a very high potasium requirements. 50% is required at tuber innitiation. Fundamental in metabolic processes and disease prevention. Potassium deficiency result in reduced yields.
METHODS TO INCREASE NUTRIENT UPTAKE
There are methods to help absorb nutrients when the soil temperature is low, such as Foliar Fertilization: the application of nutrients directly to the leaves.
- The plant shows rapid response to foliar application.
- Foliar applications during the growth cycle help in increasing tuber size.
- Vesicular Arbuscular mycorrhizal (VAM) is a fungus that penetrates the cells of the root, establishing a symbiotic relationship with the plant. Application of VAM provides mineral nutrients to the plant and, in return, the plant delivery sugars and other products of photosynthesis to the fungus. It can increase the availability of P, Ca, Mg, Zn, Fe, Mn and B.
OPTIMAL FERTILIZATION
The development of optimal fertilization program, based on critical growing periods, is key to achieving high yields when growing potatoes.
Nutritional deficiency and a wrong nutrition plan, especially at a wrong timing duriing the growth, affects crop yield and quality.
The design of an optimal fertilization program should be based on the nutritional uptake, related to the target yield, and field test results, such as soil, water and tissue analysises.
NUTRIENTS – SUMMARY TABLE
| ELEMENTS | DEFICIENCIES | EXCESSES |
|---|---|---|
| Nitrogen | Reduced total yield Reduced tuber sizing Pale stunted foliage | Delayed maturity Excessive top growth Hollow heart & growth cracks Reduced tuber specific gravity Difficulty in top killing |
| Phosphorus | Reduced early vigor Delayed maturity Reduced yield | Ties up other elements such as calcium and zinc |
| Potassium (Potash) | Reduced nitrogen uptake Reduced yield Increased storage black spot | Reduced tuber specific gravity Reduced calcium and/or magnesium uptake Poor soil structure |
| Calcium | Reduced root growth Deformed foliage growth tips Reduced yield Reduced tuber quality Poor soil structure | Reduced magnesium uptake |
| Magnesium | Reduced photosynthesis rate Reduced yield, Reduced tuber formation | Reduced calcium uptake |
