Modern sweet cherry production is increasingly moving away from programmes based on the maximum number of crop-protection treatments and towards comprehensive risk management. This includes managing crop load, fruit size, rain-induced cracking, pests and diseases, as well as pesticide residues.
This is the approach being implemented at Prodcar, a commercial fruit farm in Negureni, Moldova, where intensive tree-training systems, biostimulants, physical orchard protection, biological crop-protection products and digital monitoring tools are used as part of an integrated production system.
This article also provides access to a video filmed at the farm during a study tour by fruit and vegetable producers from Uzbekistan, organised under an FAO/EBRD initiative. The video allows readers to hear the discussions directly and see some of the technologies in practical use.
Farmer Nicolae Pascal and FAO consultant Sergiu Alba explain the farm’s business model and the production technologies applied in the orchard.
The farm’s commercial objective is very clear: the goal is not simply to maximise yield, but to produce large-calibre sweet cherries suitable for export to markets with particularly stringent requirements for fruit quality and pesticide residues.
A fruit diameter of around 28 mm is regarded as an important minimum commercial benchmark. The price differential between large-calibre cherries and fruit below 28 mm can be substantial, making the consistent production of large fruit critically important for profitability.
Different training systems for intensive orchards
Several tree-training systems are used on the farm.
One orchard block is trained to the UFO – Upright Fruiting Offshoots – system, based on vertically oriented fruiting shoots. Other blocks use conventional or modified spindle systems.
These are not experimental or exotic systems. UFO and slender spindle are among the training systems currently used in intensive sweet cherry production.
Sweet cherries on the farm are also grown on Gisela 6 rootstock under spindle-type training systems.
Sweet cherry cultivars mentioned during the farm visit include Regina, Lapins, Ferrovia, Kordia, Royal Helen, Samba and Ferdouce.
The objective is large fruit, not simply maximum yield
Crop-load management is one of the key elements of the farm’s production strategy.
A high number of fruitlets per tree is not necessarily an advantage. If the tree is excessively cropped, its assimilates and other resources have to be distributed among too many fruit, making it more difficult to achieve the required commercial fruit size.
This can be particularly important in highly productive and some self-fertile cultivars.
Crop load is therefore regulated beginning at flowering. If necessary, additional manual thinning is later carried out using scissors. According to the farm specialists, some orchard blocks have to be thinned in several stages.
The discussion also refers to a practice described informally as “burning flowers with nitrogen”. In practice, this refers to chemical blossom thinning using a product based on a nitrogen-containing compound.
The purpose of the treatment is to remove part of the flowers before they develop into fruitlets. The more desirable portion of the bloom is retained, while part of the later flowers is removed.
If chemical blossom thinning does not reduce the crop load sufficiently, it is followed by manual thinning.
Once the number of fruitlets has been reduced, the remaining fruit have access to a greater share of the tree’s assimilates and therefore have greater potential to achieve a larger final size.
The grower may therefore deliberately sacrifice part of the potential fruit number in exchange for a higher proportion of marketable, large-calibre fruit and a potentially higher selling price.
Biostimulants to support fruit size and quality
The farm uses biostimulant products based on the brown seaweed Ecklonia maxima, with several applications made during the growing season.
Glycine betaine is also applied at least twice.
During the interview, these products are associated with improved fruit size and greater plant tolerance to abiotic stress. Glycine betaine is additionally used as part of the farm’s strategy to reduce fruit cracking and mitigate the effects of spring frost.
There is scientific support for the broader approach. For example, a 2024 study involving the Early Bigi and Lapins cultivars found that treatments with glycine betaine and products based on Ecklonia maxima improved a number of fruit-quality characteristics.
Under some treatments, fruit size increased by 13.4% in Early Bigi and by as much as 47.2% in Lapins.
At the same time, the researchers emphasised that responses were strongly dependent on the cultivar and treatment programme.
Biostimulants should therefore be regarded as one component of an overall fruit-quality management strategy rather than as a universal means of guaranteeing larger fruit.
Rain-induced cracking – one of the major production risks
Rainfall during the ripening period can turn a high-quality sweet cherry crop into a substantial volume of non-marketable fruit within a matter of days.
In the year when the video was filmed, farm specialists described rainfall conditions as particularly difficult.
A cracked sweet cherry is not only downgraded because of its appearance. Damage to the fruit skin creates entry points for pathogens, meaning that what starts as a physiological disorder can quickly develop into a plant-health and post-harvest disease problem.
Glycine betaine is one of the tools used on the farm as part of the strategy to reduce cracking.
Current scientific literature does identify glycine betaine among the compounds with potential to reduce susceptibility to rain-induced cracking in sweet cherries. However, its effectiveness depends on cultivar, weather conditions and the combination with other management practices.
Such treatments cannot therefore fully replace physical protection against rainfall.
Minimising chemical treatments to expand market opportunities
An important feature of the farm’s crop-protection strategy is its effort to reduce dependence on conventional chemical plant-protection products, particularly as harvest approaches.
The commercial reason is clear: the lower the pesticide-residue profile of the fruit, the greater the opportunity to supply highly demanding supermarket chains and export markets in the EU.
For pest management, the farm uses products based on polymers, botanical extracts and naturally derived alkaloids, as well as repellents and pheromone-based systems.
Disease-control programmes also include potassium bicarbonate products and microbiological plant-protection products.
According to the farm specialists, conventional synthetic fungicides are used as selectively and sparingly as possible.
The farm does not describe this production system as organic. The objective is different: to minimise both the number of detectable active substances and their residue levels in marketable fruit.
This distinction is important.
The strategy is not to abandon plant protection, but to move away from routine calendar spraying towards a system in which every treatment should be justified by an identified agronomic risk.
Bacillus subtilis as an alternative to additional late-season fungicide pressure
The use of products based on Bacillus subtilis becomes particularly interesting as harvest approaches, when the options for conventional fungicide applications become increasingly restricted.
Following rainfall, these bacteria are used to help suppress the development of rots on cracked fruit.
In some cases, the damaged area dries and further deterioration of the fruit slows down.
Nevertheless, a cracked cherry remains defective.
Where only a relatively small number of affected fruit are present and sufficient labour is available, damaged cherries can be removed manually. Where fruit are passed through a grading line, cracked and otherwise defective fruit may be rejected automatically by the sorting equipment.
Biological crop protection is therefore used primarily to reduce secondary infections and associated losses. It does not restore a cracked fruit to full marketable quality.
The most difficult period: pests immediately before harvest
A significant part of the interview concerns a pest referred to as “drosophila”.
Based on the description of damage to ripening sweet cherries, the pest is most likely Drosophila suzukii, commonly known as spotted-wing drosophila.
Its timing makes it particularly difficult for commercial growers.
The fruit is already approaching harvest, when the use of many insecticides becomes undesirable or restricted because of pre-harvest intervals and export-market residue requirements. At the same time, infestation can quickly make the crop unmarketable.
The discussion describes affected fruit becoming soft, developing sour or fermentative characteristics and ultimately having to be discarded.
One of the farm’s principal tools against this risk is the physical exclusion of pests using fine-mesh netting.
The orchard perimeter is enclosed, access points are carefully managed and the bottom of the netting is secured to make it as difficult as possible for pests to enter from outside.
An additional advantage is that exclusion netting can reduce the pressure from other insect pests as well, thereby lowering the need for insecticide treatments.
Netting performs several functions at once
Protective netting in the orchard is not used solely for insect exclusion.
Some of the structures also provide hail protection.
The interview additionally refers to a material with reflective properties that reduces the amount of solar radiation reaching the fruit.
The objective is to reduce fruit overheating and skin damage under conditions of intense solar radiation and high temperatures.
A single infrastructure investment can therefore potentially perform several functions at the same time:
- hail protection;
- partial modification of the orchard microclimate;
- reduction of sun-related fruit damage; and
- physical exclusion of insect pests.
The technical characteristics of the netting are nevertheless critical.
Mesh size, shading percentage and spectral properties need to be selected according to the intended function because excessive shading can adversely affect fruit colour development, soluble solids accumulation and tree physiology.
Export markets increasingly shape crop-protection programmes
One of the most important parts of the discussion concerns not only agronomy, but also the economics of plant-protection decisions.
According to Nicolae Pascal, some buyers impose requirements limiting the number of detectable active substances in the fruit and require residue levels to remain substantially below the official Maximum Residue Levels, or MRLs.
The discussion mentions specifications involving a maximum of five active substances and different percentages of the official MRL.
For the farm, such requirements fundamentally change the logic of crop protection.
The question is no longer simply whether a pest or disease has been controlled.
Every additional product applied during the season can potentially increase the number of active substances detected in the final laboratory analysis and, consequently, exclude the grower from an attractive premium market.
The farmer therefore tries to replace part of the conventional pesticide programme with physical barriers, biological control products, suitable contact products and more precise identification of when treatment is actually necessary.
Maintaining such a strategy becomes particularly difficult in rainy seasons.
Disease pressure increases precisely at a time when the possibilities for additional conventional chemical protection become increasingly limited as harvest approaches.
The appearance of the stem also has commercial value
An interesting technological trade-off arises on the grading and packing line.
Mechanical sorting can efficiently remove cracked and damaged fruit. However, according to the grower, the particular grading line used at the farm can sometimes damage or partially detach the fruit stem.
The damaged part of the stem then dries, reducing the visual freshness of the product.
For some buyers, particularly in markets where freshness is assessed heavily on appearance, an intact green stem, glossy skin and an overall freshly harvested appearance can be so important that the buyer may prefer fruit that has not passed through a particular stage of mechanical handling.
This demonstrates that post-harvest handling technology must be adapted not only to objective quality parameters, but also to the specifications and preferences of the target market.
Hydrogen peroxide and silver in post-harvest treatment
The discussion also covers a product combining hydrogen peroxide and silver, considered for use during cooling or on the post-harvest handling line.
A product called Vitoxid, reportedly manufactured in Vinnytsia, Ukraine, is mentioned.
The purpose of this type of treatment is to reduce microbial load on fruit, water and/or equipment during post-harvest handling.
Gisela 5 and Gisela 6: managing vigour and crop load
Different parts of the orchard use Gisela 5 and Gisela 6 rootstocks.
Some blocks carry particularly heavy crops, while the grower nevertheless estimates that a large proportion of the fruit achieves the required large commercial size.
The interaction between cultivar, rootstock, training system and crop load is fundamental.
Dwarfing and semi-dwarfing rootstocks make it possible to establish compact, intensive orchards, but they also require much more precise management of nutrition, irrigation, pruning and crop load.
A weather station instead of spraying “because a few days have passed”
One of the clearest examples of the farm’s production philosophy is the use of digital weather stations equipped with multiple sensors, combined with disease forecasting models based on recorded weather data.
The farm deliberately avoids the approach of saying: “It has been two days since the previous spray, so it is time to treat again.”
Instead, the agronomist has access to weather-station data and an application that calculates the infection risk for specific diseases.
If weather conditions are not conducive to infection, a treatment can be postponed or avoided.
If the model indicates that an infection period is approaching, the crop-protection intervention can be carried out preventively, before visible symptoms develop.
This is especially important in the management of Monilinia diseases.
The objective is not to wait until infected fruit or flowers become visible and then begin treatment. The aim is to identify a high-risk infection window in advance and protect the crop at the appropriate time.
The farm weather station records parameters including temperature, relative humidity and rainfall.
Additional sensors are used to monitor soil conditions, leaf wetness, and wind speed and direction.
Irrigation is also based on actual crop needs
Irrigation is not managed solely according to a fixed calendar.
Soil sensors allow the agronomist to assess soil water status at different depths.
During the discussion, a threshold of approximately 40 centibars is mentioned as one of the indicators used when deciding whether irrigation should be initiated.
The farm uses drip irrigation, while Watermark soil-moisture sensors have been installed at depths of 20, 40 and 60 cm to monitor soil water availability.
This is another example of the same underlying principle: intervention should be based on measured need rather than simply on a routine schedule.
The bigger picture: the intensive orchard as a risk-management system
The experience of this farm is interesting not because of any single product or treatment, but because of the overall architecture of the production system.
High marketability of sweet cherries is achieved through a combination of:
- crop-load management;
- appropriate training systems and rootstocks;
- biostimulant use;
- protection from rainfall and excessive solar radiation;
- physical barriers against pests;
- biological crop-protection products;
- pesticide-residue management;
- automated disease-risk monitoring; and
- precision irrigation.
It is the combination of these components that allows the producer to pursue two objectives that are becoming increasingly difficult to reconcile: producing large, visually flawless fruit while at the same time minimising the pesticide-residue footprint of the final product.
As buyer requirements become increasingly stringent, this type of integrated approach is likely to become one of the key directions in the development of intensive sweet cherry production.
The visit to the farm was organised under the FAO/EBRD initiative on climate and environmental sustainability in the agrifood sector, within the subcomponent “Greening Uzbekistan’s Fruit and Vegetable Value Chain”, with the support of Moldova’s Federation of Agricultural Producers FARM.
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