The cultivars of the domestic plum (Prunus domestica) come from the crossing of wild-growing species of the alech plum (Prunus cerasifera var. Divaricata,) and the blackthorn (Prunus spinosa). Plum cultivation is widespread around the world.
The fruit of plums are drupes of various shapes and colors – depending on the species. Due to their attractive appearance and unique taste, they are intended for direct consumption and are used in the processing industry.
There are 4 groups of plums (subspecies):
- Insititia plums – in this group the most popular are the Mirabelle plums.
- Italica plums – this group includes mainly Greengage plums.
- Intermedia plums – the group consists of 4 subgroups:
– egg-shape- varieties characterized by the size and shape similar to an egg
– date (red) plants – these varieties have the most elongated shape of all plums
– oval shape – the fruits of these varieties are slightly more elongated than the egg ones and much larger
– hunter half-Hungarian – medium or large fruit, oval in shape - Oeconomica plum – this group includes common (purple) plums – commonly cultivated varieties.
The best soil for plum cultivation is fertile, humus soils, quite heavy, but airy with a pH of 6–6.7. Plums grow poorly in cold, wet and clay soils, as well as in light, easily drying out soils.
Plum cultivation is favored by a temperate humid and warm climate and a sunny sites.
Plums begin their vegetation and bloom early, therefore they are exposed to frost damage, which can cause fruit buds to fall. These losses result not only from damage to the buds or flowers in full bloom, but also from damage to the base of the buds, which contain the vascular bundles responsible for supplying the buds with essential nutrients.
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).
Temperature drops during flowering also reduce the activity of pollinating insects. The colder it is, the worse the conditions for the pollinating insects flight.
Drought is also unfavorable, as flowers exudate less nectar and are therefore less attractive to pollinating insects.
An effective way to improve the efficiency of pollination is to use the TYTANIT® biostimulant at the beginning of flowering, which increases the number of germinating pollen on the stigmas. During this period, the optimal supply of boron (MIKROVIT® BORON TURBO) effectively supports the process of fruit formation.
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.
The choice of the method of mineral nutrition of plums and the dose of fertilizers should be adapted to the fertility status of the soil and the condition of the trees (soil and leaf analysis, as well as visual assessment of plants). An important supplement to soil fertilization is foliar plant nutrition.
It enables the trees to be optimally supplied with nutrients in subsequent development stages, which not only guarantees abundant fruiting in a present season, but also promotes the formation of flower buds for the next year. An important role in the cultivation of plums is also played by post-harvest feeding of trees (before the natural discoloration of the leaves). It increases the yield potential for the next growing year and increases the winter hardiness of trees.
Foliar feeding treatments are now an integral part of the mineral nutrition program for plum trees, because:
- support the supply of 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 sulfur (PLONVIT® SULVIT)
- provide plants with nutrients that are difficult to be taken up from the soil, for example: boron (MIKROVIT® BORON TURBO or MIKROVIT® BORON) – a typical symptom of boron deficiency is poor fruit setting and appearance of chat fruit, cracking and corking
- provide plants with nutrients that directly affect the firmness and color of fruit: phosphorus (PLONVIT® PHOSPHO or PLONVIT® FOSTAR), potassium (PLONVIT® KALI or PLONVIT® KALPRIM)
- support the supply of calcium to plums, which is a nutrient that is not mobile in the plant (OPTYCAL®, PLONVIT® CALCIUM TURBO) – calcium increases skin flexibility, reduces fruit cracking, and increases their shelf life in market trade.
The good condition of plum trees throughout the growing season determines the yield of plums.
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, has shielding properties for plants: ALKALIN™ PK 10:20.
All of these discussed actions significantly affect the yield increase and its quality parameters.
