1. Cherry Fertilizer Recommendations
2. How Our Recommended Fertilizers Work on Cherry
3. Trial Data For Our Recommended Cherry Fertilizers
Lono is Levity’s flagship nitrogen fertilizer which greatly improves fruit number and size, and promotes good root growth. Lono provides cherry trees with ‘Stabilized Amine Nitrogen’ which focuses growth on fruit development rather than vegetative growth.
Albina is Levity’s highly efficient calcium fertilizer which improves fruit set, fruit firmness and reduces susceptibility to cracking, fruit drop and other physiological disorders. Conventional calcium fertilizers give erratic results because fruit are not always able to absorb calcium, making applications inefficient. Albina uses Levity’s special LoCal technology to make it easy for fruit to absorb.
Sulis is Levity’s fertilizer which helps cherries to build maturity (colour and brix). Sulis maximizes the function of the enzymes responsible for maturity in cherries and results in better colour and brix, meaning that farmers can harvest earlier.
As the primary plant nutrient, cherry growers need to supply nitrogen for growth of the crop. However conventional nitrogen fertilisers disproportionately favour vegetative growth, meaning farmers are faced with a difficult balancing act between supplying enough N to achieve a good crop, and pushing out too vigorous shoot growth which detracts from yield and can increase fruit drop.
It is nitrates that drive vegetative growth. Nitrates are processed in leaves, and as they accumulate cherry trees increase synthesis of the growth hormone auxin. The more nitrates the tree takes up, the more auxins are produced and the more the tree pushes towards building vegetation rather than supporting fruit development.
Different forms of nitrogen like amine and ammonium do not produce this ‘auxin effect’ but despite this switching to conventional ammonium and urea nitrogen sources still tends to produce increasingly vegetative growth as supply increases. This is due to the inherent instability of nitrogen fertiliser in the environment.
Regardless of the form applied most N given to cherry orchards does not get taken up by the crop, and the majority that does make it into the trees does so in the nitrate form. This is due to bacterial activity that alters nitrogen from the form applied to nitrates, with losses along the way through leaching and volatilisation.
Levity have developed LimiN, a technology that holds nitrogen in the amine form, preventing conversion to nitrates. Our product Lono supplies stabilised amine nitrogen, and this can be used by farmers to help cherry trees better allocate growth via a process known as ‘growth partitioning’.
When trees are exposed to stabilised amine N via applications of Lono, they allocate growth differently. The crop becomes less ‘apical dominant’ developing more branching rather than shoot extension, better root development, and greater emphasis on flower and fruit development.
By regularly applying small doses of Lono alongside conventional N inputs, farmers can increase the number and size of cherries produced by the tree, reduce fruit drop and improve quality.
Although fruit quality in cherries is strongly linked with fruit calcium levels, it is rarely the case that the whole tree is calcium deficient. Even on crops with high levels of cracking (a problem associated with low fruit calcium) there are frequently no signs of calcium deficiency in leaf analysis.
Unlike most other nutrient’s calcium is not phloem mobile, instead plants move calcium in the xylem with water. This means calcium moves through the plant in the same direction as water flow, moving through the plant from roots to leaves via transpiration stream.
This makes calcium movement susceptible to water availability and weather conditions, hence bitter pit increases when water flow is restricted by growing conditions. It also makes getting applied calcium to fruit tricky, as fruit is low in transpiration so receives little throughput of calcium when compared to other parts of the plant like leaves.
Absorption of calcium is also linked to presence of the auxin hormone. Tissues high in auxin absorb calcium easily, but tissues low in auxin have difficulty absorbing calcium no matter how much is available. Given that mature cherries are naturally low in auxin, this makes absorption of calcium rather than availability of calcium the main driver in susceptibility to cracking in cherry crops.
When we look at the physiology of the fruit, we can learn a little about best timings for reducing cracking incidence. Auxin levels are highest in fruits between flowering and when the fruit is 5mm in size, this is the main period of cell division (which is powered by auxins).
As the fruit gets bigger it is focused on increasing the size of cells rather than creating cells, and auxin levels drop making it progressively harder to get calcium into fruit as it increases in size.
To help improve calcium levels in cherries Levity have developed LoCal, a chemistry that improves calcium absorption in the absence of auxins. This helps cherries (naturally low in auxins) to properly absorb calcium.
Albina uses LoCal chemistry to deliver calcium into cherries, which allows farmers to use lower application rates and less frequent applications than with conventional calcium fertilisers. Albina (and other products using LoCal) have been demonstrated to improve calcium content and quality of cherry crops in independent trials.
Sulis builds maturity (colour and brix) in cherries. It works by supplying molybdenum and boron in a special formulation that helps the fruit maximise the function of the enzymes responsible for maturation, building better levels of colour and brix to allow earlier picking.
The processes of maturation require molybdenum and boron, but as molybdenum does not produce visible deficiency symptoms, the enzymes are often not adequately functioning, leading to a slow build of colour and sugars. The Blush technology that powers Sulis activates the plant’s natural process of maturity, whilst ensuring these key nutrients in the process are available.
Sulis helps cherries build better levels of colour and brix to allow earlier picking of high-quality fruit. It promotes the processes of maturation that are normally triggered by the hormone ABA. Importantly, Sulis does this without causing a spike in ethylene, which can retard shelf life and create quality problems.
Sulis also contains cell wall stabilisers, so that whilst colour and sugars build, the developing cherries can also maintain firmness. Normally, there is a trade-off between colour and sugar formation and softening, Sulis is designed to manage this process so that farmers can get the taste they need whilst still picking fruit that stays firm in storage.
Sulis is proven to improve colour and brix and to bring forwards harvest in multiple field trials in both the US and China.
Cherry growers in the Southern hemisphere must work harder to get colour, and shelf-life and to reduce physiological disorders. In the southern hemisphere the ozone layer is thinner and a higher level of UVB light occurs.
Photo-oxidative stress generated by high UVB causes heightened production of toxic reactive oxygen species (ROS) during photosynthesis. ROS damage plant cells, ultimately leading to cell death if they build up in plant tissue, therefore plants have mechanisms to deal with them. Namely production of anti-oxidants such as anthocyanins and carotenoids and enzymes such as superoxide dismutase (SOD).
For crops to grow well where there is a high UV level, plants must use anti-oxidants in order to protect themselves. These antioxidants are the main source of colour in fruit crops, with yellow, orange and red pigments coming from carotenoids and red, blue and purple pigments coming from flavonoids.
From a practical agronomic point of view this means that colours and flavours that come from anti-oxidants are metabolised by the fruit as they are used to prevent damage from ROS. This means that it can be harder to hold colour in crops like cherries.
So what can we do about this? Firstly we need to understand that the problem is not caused by the plant not producing colour, rather it is due to the colour being metabolised. Anything a grower can do to reduce stress will improve the situation (most kinds of stress induce ROS increases, not just UV), so paying attention to minimising stress in general can help.
To help growers with this Levity have developed Indra, a fertiliser that can reduce the effects of stress and help plants produce higher levels of antioxidants. Indra can help improve yield and quality in cherry crops where UV leads to poor colour retention. It can also help protect yield from other kinds of crop stress including salinity, drought and high temperatures.
Our cherry fertilizers are independently trialed around the world to make sure that they excel above conventional fertilizers in all agronomic and weather conditions.
In this section explore some of the independent trials of our recommended fertilizers for cherry.
In this 2020 US trial on the variety Cristalina Lono K was applied at 5L/Ha during flowering, and the impact was assessed on set, fruit size, colour and brix. The fruit set was improved over control by 28%, which was 7 percentage points over the grower standard treatment.
Although the setting was significantly higher, fruit size was not reduced, brix was improved, and colour was improved with a higher fraction achieving colour grade 7.
In this 2020 trial on Cristina a full programme of Lono K, Albina and Sulis was used and the crop assessed for all quality parameters.
The Levity programme gave significant improvements in brix and colour, with higher grade fruit produced than with the standard programme or control. Despite having higher brix and better colour, there was no trade off with shelf life with the Levity programme significantly improving fruit firmness both pre-harvest and post-harvest.
In this trial in Shandong province China a programme of Albina and Sulis was assessed on multiple local cherry varieties. The treated trees had significantly higher fruit numbers, and improved colour and brix. The colour improvement allowed the crops to be harvested more than a week early, allowing farmers to access better prices in the market.