Sweet cherries are dessert fruit – intended for the fresh fruit market. Their quality is primarily determined by: size and color, taste (sugar content and fruit acidity) and flesh firmness. The green and flaccid (non lignified) stalk is also important – perceived by consumers as an indicator of the freshness of the fruit. The color, size and ripening time of the fruit depend on the variety.
The fertile, well aerated soils with a pH of 6.5–6.8 are the best for growing sweet cherries. Sweet cherries do not tolerate too high a level of groundwater – it should not exceed 2 m.
Sweet cherry trees are susceptible to frost, although the most resistant varieties can withstand temperature drops down to -25°C. On the other hand, spring frosts are a particular threat and risk, because sweet cherry is one of the fruit crop that begin their vegetation very early. Flower buds on trees can swell already in the pre-spring period – even at the beginning of March (in the Northern Hemisphere). Thus, in early spring, flower buds, flowers and fruitlets are exposed to damage caused by a temperature drop below 0°C. During the full flowering period, frost on the level of -3°C may completely destroy flowers. To counteract the effects of frosts, fruit growers use various methods, including spraying trees with preparations that increase the concentration of mineral salts in plant cells, thanks to which they become more resistant to freezing (PLONVIT® KALPRIM, ALKALIN™ K+Si).
In stone trees – in contrast to pome trees – flower and leaf buds are formed separately. Stone trees first develop flowers, pollinate them, and simultaneously develop leaf buds.
Therefore, in stone trees it is very important to stimulate the best possible development of leaves (TYTANIT®, PLONVIT® NITROMAG, GROWON®), because when there are too few of them or they are not well developed, a significant drop of fruitlets may occur.
Obtaining an high yield and high-quality of sweet cherry fruit depend on many biological and cultivation factors. One of them is the proper supply of trees with nutrients. Stone tree crops have greater nutritional requirements compared to pome crops.
The selection of the method of fertilization of sweet cherries and the dose of fertilizers should be adjusted to the condition and age of the trees and the soil’s fertility status, the level of which can be determined by chemical soil analysis. An important supplement to soil fertilization is foliar plant nutrition. Its main advantage is the quick and effective supply of the most-required nutrients to trees at particular stages of development.
Presently, foliar treatments are an integral part of the mineral nutrition programs for sweet cherry trees, because:
- support supplying plants with major nutrients: nitrogen (PLONVIT® NITRO or PLONVIT® NITROMAG), phosphorus (PLONVIT® PHOSPHO or PLONVIT® FOSTAR), potassium (PLONVIT® KALI or PLONVIT® KALPRIM), magnesium (MIKROKOMPLEX™) and sulphur (PLONVIT® SULVIT or PLONVIT® BOROSULF)
- provide plants with ingredients that are difficult to be taken from soil, e.g. boron (MIKROVIT® BORON TURBO or MIKROVIT® BORON)
- provide plants with ingredients that directly affect the fruit color and firmness, as well as the color, quality and strength of the fruit stalk: phosphorus (PLONVIT® PHOSPHO or PLONVIT® FOSTAR), potassium (PLONVIT® KALI or PLONVIT® KALPRIM), manganese (AMINO ULTRA® Mn-22 or MIKROCHELAT™ Mn-13 or MIKROVIT® MANGANESE)
- support supplying sweet cherry trees with calcium, which is a low-mobility nutrient in the plant (OPTYCAL®, PLONVIT® CALCIUM TURBO – calcium increases the flexibility of the peel, reduces fruit cracking and increases their shelf life in market trade).
In the cultivation of sweet cherries, large losses are caused by fruit cracking due to rainfall during fruit ripening and harvest – especially after periods of low soil moisture.
One of the methods of reducing cherry cracking is spraying trees with a solution of calcium fertilizer (PLONVIT® CALCIUM TURBO). There are recommended standard spraying each time directly before the expected rainfall or during rainfall.
Sweet cherry is a crop that requires proper care after fruit harvesting, i.e. in the period from the end of harvesting to the end of vegetation in autumn (for a period of about 3 months).
- The first goal of these treatments is to keep the leaves in good condition on the trees, because premature defoliation (caused by diseases or nutrient deficiency) leads to tree weakness, a decrease in their resistance to frost and a significant drop in yield.
Therefore, first (after standard tree pruning), it is recommended to feed trees with nitrogen (PLONVIT® NITROMAG or PLONVIT® NITRO) and magnesium (MIKROKOMPLEX™). In the next treatment, the plants should be provided with a set of NPK with microelements (PLONVIT® OPTY or PLONVIT® GEL) and magnesium (MIKROKOMPLEX™). The foliar treatments with the use of copper products (MIKROCHELAT™ Cu-15) are also used to increase tree resistance to diseases.
- The second important goal of feeding sweet cherry trees before winter dormancy is to enable trees to accumulate nutrients needed for their development in early spring.
In spring, low temperature limits the effective uptake of nutrients from the soil. Therefore, before the beginning of leaf color turning, trees should be fed with a fertilizers containing zinc and boron (BORZIN™ TURBO) and potassium (PLONVIT® KALPRIM or ALKALIN™ K+Si).
These treatments are the first ones to prepare trees for the new growing season.
The good condition of sweet cherry trees throughout the growing season determines the yield of sweet cherries. 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 are the highly alkaline line of fertilizers ALKALIN™, which, in addition to the basic functions of bringing in nutrients, have shielding properties for plants: ALKALIN™ K+Si, ALKALIN™ KB+Si, ALKALIN™ PK 10:20.
All of these discussed actions significantly affect the yield increase and its quality parameters.
