Often the plum leaves the fruits still green, and the gardener wonders why. To help the plant, you first need to understand the cause of what is happening.
Three reasons why unripe plums massively fall
Fruits fall en masse if during flowering a tree comes under freezing frost. It is difficult to notice this with the naked eye, because the petals remain white. However, if you look closely, you can see that the pistil of the flower is painted in brown or black, instead of green. Most often, for this reason, plums fall in the middle and northern strip of Russia.
You can notice the plumage of plums on the site when growing self-infertile varieties. The ovaries and unripe fruits of such trees show off most often. To prevent this from happening, pollinators with suitable flowering periods are planted nearby.
One of the reasons green and unripe plums fall off is improper tree care. Plum can pour in from a lack of moisture, because its roots are located in the surface layers of the soil. The tree is demanding on watering and does not tolerate even short-term drought. In the absence of rain, plums are watered abundantly and more often than other fruit trees.
Important! Watering the plum needs 3-5 times a season, while the earth needs to be wetted by 60 cm.
How to determine if an unripe plum falls due to a lack of nutrients
When there are not enough nutrients in the soil, the fruits begin to crumble. This happens at different stages of their development. For example, due to a lack of nitrogen, the ovary forms poorly and subsequently crumbles. If there is not enough potassium in the soil, unripe large plums are showered.
The timely application of mineral and organic fertilizers will help to avoid soil depletion. It is best to use high-speed top dressing. They are prepared on the basis of mullein or bird droppings.
Important! It is necessary to introduce nitrogen fertilizing in the first half of summer, otherwise the winter hardiness of the tree will decrease.
The main diseases of the plum, due to which the unripe fruits fall
Unripe plums can fall due to tree diseases. There are several of them:
• kleasterospiriosis;
• coccomycosis;
• fruit rot.
You can recognize kleasterospiriosis by characteristic brown spots, which are surrounded by a dark border. Fungal disease affects all parts of the tree, can cause gum disease. Even green fruits are affected to the very bone, stop growing.
Pathogenic spores overwinter in plant debris and land, and the disease progresses in early spring. This is facilitated by heavy rains and high humidity.
They fight the disease by thinning the crown. In the spring, preventive spraying is carried out with a 1% solution of Bordeaux fluid. In autumn, all plant debris is taken out of the site and burned, and the soil under the tree is dug up.
Coccomycosis manifests itself on the outside of the leaf with small reddish-brown spots. With the course of the disease, the spots increase, and a white coating appears on the inside of the leaf. At the end of the first half of summer, the leaves crumble, plums stop developing and fall off.
The fungus overwinters on fallen leaves, so the measures to combat pathogenic flora are the same as with kleasterospiriosis. In addition, complex fungicides are used.
Fruit rot is formed on overripe fruits, winters well on the scavenger, and in spring affects green ovaries. Plums stop developing and fall off.
The methods of struggle are the same as with any fungal disease.
Important! All fall carrion in the autumn must be removed from the site.
How to deal with pests so that unripe plums do not fall
Pests often bother the tree, as a result of which the fruits stop developing and fall unripe. The most common ones are:
• plum moth;
• plum sawfly;
• a toddler.
The plum moth is a dark brown butterfly that lays its eggs in green fruits. The pest leads a nocturnal lifestyle, so it is difficult to notice it. Dark pink caterpillars emerge from the eggs; they feed on the pulp of unripe fruits, eating it around the bone. Damaged fruits can be noticed by the characteristic amber-colored drops that stand out from the plums.
In winter, caterpillars pupate and settle in cracks in the bark, soil or plant debris. The fight against them begins in the fall. To do this, collect all the fallen plums, dig the soil around the tree, clean out the old bark, whiten the tree trunk and establish hunting belts.
In the spring, as a prophylaxis of the appearance of the pest, they are sprayed with a complex insecticide. The treatment is repeated several times, especially during the mass summer of insects.
Another insidious plum pest is a sawfly. This is a bug that feeds on the pulp of green fruits, eating it along with the bone. The ovary ceases to develop and falls off en masse. The pest overwinters in the soil, so in autumn you need to dig a lot well.
To prevent the sawfly from appearing, it is necessary to spray the tree before flowering with Confidor or Aktara preparations.
The butterfly butterfly is another reason why unripe fruits fall off the plum. It appears at the end of May or the beginning of June, therefore trees of an early flowering period suffer mainly.
It’s hard to spot a bear. She lays eggs in the bone of the fetus, which continues to develop. Butterfly larvae eat out a young bone, the fruits crumble, being already large, almost ripe.
Important! If you look at the fallen plum, then there are no external damages on it. The pulp of the fruit is whole, untouched by the pest. There is no bone inside.
Repeated treatment of the crown with Confidor will help prevent the spread of the pest. The first spraying is carried out before flowering and immediately after it. The following treatment is repeated after a few days.
The pest overwinters in plant debris, so all dry leaves and weeds are removed from the site.
