The potato (Solanum tuberosum L.) is a popular species grown in many countries of the world. Medium-compact or compact soils with medium or high humus content, rich in nutrients and slightly acidic are optimal for its cultivation.
Due to the length of the growing season, potato varieties are classified into 5 classes:
- very early – 60–90 days
- early – 90–110 days
- medium early – 110–125 days
- medium late – 125–135 days
- late – over 135 days.
Potato tubers contain 15–25% dry weight, the rest is water. Starch content is the basic quality parameter of a potato. Content of fructose and glucose, which are known as reducing sugars (causing tuber darkening after peeling), is also important.
Potato tuber internal and external quality characteristics largely depend on the variety, technology of cultivation, fertilization, protection and harvesting. Content of starch and reducing sugars is also influenced by the weather during the growing season and plant fertilization.
Depending on the intended use (direction of use), certain utility characteristics of tubers are required.
- In the case of potatoes for consumption, the following features are important: taste, consistency, mealiness (flowability), moisture, tendency to overcook, as well as darkening of raw and cooked tubers.
- In the case of potatoes for processing, these criteria are more specific, such as:
tubers intended for French fries
- size (diameter) ›55 mm
- oblong or oblong-oval shape
- starch content: 14–16% of fresh weight
- reducing sugar content: 0.25–0.5% of fresh weight
tubers intended for potato chips
- size (diameter): 40–60 mm
- starch content: 16–21% of fresh weight
- reducing sugar content: 0.05–0.15% of fresh weight (maximum 0.3%).
In the case of potatoes for industrial processing, the starch content is the main quality criterion.
Providing nutrients in the right amount and form at the right time is a necessary condition for obtaining a high yield of potato tubers with the required quality characteristics.|Apart from basic soil fertilization, foliar fertilization is a standard.
- Nitrogen (N) is the basic nutrient essential for plant life. By controlling the dose, timing (dose splitting) and method of nitrogen supply, you can influence the tuber size forming process. Potato responds very well to foliar nitrogen fertilization (PLONVIT NITROMAG, PLONVIT NITRO).
The use of a higher dose of nitrogen increases yield of tubers by increasing their weight, but the starch content in a yield unit decreases with increasing doses of N. The yield quality may also be reduced, especially in the case of very early and early varieties. Both, deficiency and excess of nitrogen are disadvantageous. - P, K, Mg, S – these are nutrients that increase both, the tuber yield and the tuber starch content.
A particular quality issue is the darkening of raw and cooked tubers. It decreases with the increase of vitamin C content in tubers, which is supported by foliar potassium fertilization (PLONVIT KALPRIM or PLONVIT KALI). Potassium also reduces the content of reducing sugars.
The speed of conversion of sugars into starch is also improved by phosphorus (GROWON or PLONVIT FOSTAR or PLONVIT PHOSPHO), and this process is supported by sulfur and magnesium (PLONVIT SULVIT or MIKROKOMPLEX or MAGNESIUM SULPHATE x 7H2O).
Apart from influencing the transformation of sugars, phosphorus – when applied during the tuber setting (hooking) period – increases the number of tubers formed.
Thus, the supplying phosphorus to plants in a quickly absorbable form (GROWON, PLONVIT FOSTAR) just before this period can significantly increase number of tubers, which is especially important for low tuber setting varieties.
Foliar fertilization of potatoes with the above-mentioned elements is standard in potato cultivation. - Microelements – in cultivation of potatoes on light soils or without manure fertilization, foliar fertilization with microelements is necessary:
The good condition of plants throughout the growing season determines the yield of potatoes.
Even short-term nutrient deficiency may have a negative impact on plant growth and yield. Therefore, it is necessary comprehensive assessment of the requirements of the plants at any stage of their development. This will allow them to be properly fed and biostimulated. INTERMAG’s wide range of products, allows you to develop your own individual foliar fertilization and biostimulation program, considering local soil conditions, crop intensity, stage of plant development and availability of various products.
Particularly noteworthy is the highly alkaline fertilizer, which, in addition to the basic functions of bringing in nutrients, have shielding properties for plants: ALKALIN PK 10:20.
All of these discussed actions significantly affect the yield increase and its quality parameters.
