Crop Guides - Potato
Section 1
Fertilizer Recommendations for Potato
Lono – Yield
Lono is Levity’s flagship nitrogen fertilizer which greatly improves potato yield, root growth and size distribution. Lono provides potato crops with ‘Stabilized Amine Nitrogen’ which focuses growth on reproductive areas like tubers rather than vegetative growth like conventional nitrogen fertilizers.
Albina – Quality
Albina is our highly efficient calcium fertilizer which improves shelf life & firmness of potato tubers and reduces susceptibility to disease & physiological disorders. Conventional calcium fertilizers give erratic results because tubers are not always able to absorb calcium. Albina supplies calcium in a way which is easily absorbed in tubers and is effective all season long.
Damu – Bulking
Damu is our specialist boron fertilizer which greatly improves the bulking & yield of potato crops and safeguards quality. Damu helps the plant to use its energy to bulk up the potato tuber rather than force late season leaf growth.
Section 2
How Our Recommended Fertilizers Work on Potato
Use Lono To Increase Potato Tuber Numbers
Lono is Levity’s flagship nitrogen fertilizer. In this section we will discuss how Lono can be used to focus growth on the potato tuber rather than the foliage, in contrast to conventional nitrogen fertilizers which focus more growth on the foliage.
Nitrogen can be taken up by a potato crop in three forms: amine (NH2), ammonium (NH4) or nitrate (NO3). While nitrogen uptake dictates how fast the potato crop grows, it is the ‘form’ of nitrogen which dictates ‘where’ it grows.
Nitrate makes the crop produce more of the growth hormone ‘auxin’ which are made in the potato leaves. This results in accelerated vegetative growth (top growth of shoots) at the expense of reproductive (tubers) growth. While this does result in slightly higher yields, there is a large amount of growth energy wasted on excessive and unnecessary top growth which could be channelled into increasing yield much further.
So, is the answer to use conventional amine or ammonium nitrogen fertilizers instead? Unfortunately not. When either amine or ammonium nitrogen is applied to the potato crop it is also competed for by various bacteria. These bacteria compete with the potato crop for the available amine or ammonium nitrogen and convert it into nitrate before the potato crop is able to take up even a small amount. Therefore, by applying standard amine or ammonium nitrogen fertilizers we end up supplying the potato crop with nitrate anyway, which again results in excessive top growth at the expense of tuber development, and therefore, we don’t reach our full potential yield.
To create a favourable auxin:cytokinin balance we want the crop to take up amine (or ammonium) nitrogen but are unable to supply this effectively with conventional fertilizers.
How do we supply the potato with nitrogen which doesn’t favour excessive top growth?
Levity have developed the fertilizer Lono which uses ‘LimiN’ technology. Lono supplies the potato crop with ‘Stabilized Amine Nitrogen’. This form of amine nitrogen is unrecognisable to the bacteria which would usually convert amine into nitrate. This means that ‘Stabilized Amine Nitrogen’ is taken up by the crop in amine form rather than nitrate. By helping the potato crop to take up amine nitrogen we help it to produce more of the growth hormone cytokinin which favours tuber development rather than top leafy growth. This process (known as growth partitioning) helps us to minimise the amount of wasted energy and maximize your yields by helping the crop grow in the right place.
Use Albina to Improve Quality & Shelf Life
Good calcium levels in potato crops reduce the susceptibility to many quality problems such as Internal Rust Spot (IRS), internal browning and hollow heart, they are also key in preventing post-harvest disease and bruising. However, farmers do not get the best results from calcium fertilisers, in this section we will discuss; why, how to overcome the problem, and how Albina can be used to greatly improve calcium absorption throughout the whole season.
Why calcium fertilizers give erratic results
Calcium’s main role in potatoes is to give cell walls strength and rigidity, and symptoms of deficiency include disintegration of cell walls and affected tissue collapse which causes cell walls to collapse. However, these problems occur due to localised deficiencies, this is why the symptoms of calcium deficiency such as internal rust spot are ‘spotted’ around the potato with clear affected tissue and unaffected tissue. The crop as a whole, and even majority of the potato tuber is not deficient, it is only small areas which are deficient.
Potatoes only require small amounts of calcium and potatoes can often be deficient in calcium even when there is an abundance available to the crop. A potatoes deficiency is not dictated by the amount of calcium applied or taken up, but rather, the potatoes ability to transport and absorb calcium. This is why deficiencies occur even when conventional calcium fertilizers have been applied.
Let’s look at both calcium transport and calcium absorption in potatoes to better understand what we can do to improve calcium levels.
Calcium Transport
Calcium isn’t phloem mobile and can only be transported through the xylem. Calcium enters the plant with water and is transported upwards with transpiration. This means that calcium can only move upwards through the plant, it is physiologically impossible for the plant to move the calcium down from the leaves to the tubers. Therefore, foliar calcium fertilisers will never put the calcium in the tubers.
Targeting and applying the fertilizer in the right place is of paramount importance and often overlooked.
While trying to fix calcium problems in the tubers, applying calcium fertilizer to the foliar is ineffective. Instead, the fertilizer should be placed near the stolon roots inside the tuber zone. This can be done through drip lines or incorporated into hills at planting.
The stolon roots supply the potato tubers. The main root system usually bypasses the tubers and takes the calcium past them and up to the foliage, ensuring the calcium fertiliser is placed in the tuber zone is crucial.
Calcium Absorption
Calcium is absorbed into cells using ‘polar-auxin transport’. This means that ‘auxin’ must move out of the cell for calcium to enter. Therefore, a potato tuber cannot absorb calcium effectively if it is low in auxin, regardless of how much calcium is applied.
Tubers are naturally high in auxin when they are young and in cell division stage (5mm or smaller) and are able to effectively absorb calcium during this time. Once they become larger than this, they stop producing auxin and become inefficient at absorbing calcium. Due to this, conventional calcium fertilizers must be applied between the ‘hook-eye’ and 5mm size for the calcium to get into the potato tuber.
This gives a short window to get calcium into the crop each season, and if calcium deficiency is detected later in the season, it is unlikely to be remedied by applying conventional calcium fertilizer.
Albina provides a better way
Albina is Levity’s highly efficient calcium fertilizer and uses LoCal technology. Albina allows calcium to be absorbed by tubers even when auxin levels are low (above 5mm in size). This means that calcium applications with Albina are not limited to ‘very early season’ as calcium from Albina will be absorbed by the potato tuber all season long. Also, if you have missed the right timings for applying your calcium fertilizer, Albina can be used to remedy the situation and get calcium into your potato tubers later in the season.
Use Damu To Bulk Potato Tubers
Potatoes are a plant in which farmers must carefully balance top growth with tuber growth.
Potato Plants deficient in Boron make high levels of auxin and low levels of Cytokinins. Auxin synthesis can quickly get out of control resulting in an increased ‘nitrate affect’ and top growth accelerates at the expense of tubers.
On the other hand, potato plants with high levels of boron make lower levels of auxin and high levels of Cytokinins. This results in less top growth and better tuber bulking.
Boron can be used to regulate auxin synthesis and slow down periods of fast top growth. Quantity and timing are paramount in this balancing act because there is fine line between deficiency and toxicity with Boron.
Solution
Levity have developed Damu, a high efficiency product that allows lower rates of B to be more effective, using stimulants to increase speed of uptake and metabolism. Damu can be used during periods of excess vegetative growth to reduce auxin production and refocus the crop on root growth.
In order to produce tubers Potato plants must move sucrose from the leaves down to the tubers and roots, because Boron plays a part in this movement, it has a large impact of tuber growth.
During bulking potatoes translocate sucrose from leaves to tubers using bis-sucrose-borate, a phloem mobile complex formed between boron and sucrose.
Damu works by improving the translocation of sucrose between leaves and tubers for higher starch formations. Damu applied during bulking supplies the Boron needed to fuel carbohydrate translocation alongside Levity’s proprietary stimulant ‘Catalyst’ which stimulates the speed and intensity of the process.