Since both the apple tree and the pear belong to the same fruit crop, namely, the seed crop, their diseases are the same. For example, an ailment such as scab of apple and pear weakens trees, reduces the fruiting power and resistance to winter frosts. In this case, almost all parts of the tree suffer: flowers, ovaries, leaves, branches and fruits. But there are varieties of pears that have a relative "immunity" to this terrible fruit disease. Scab-resistant pear varieties are: Bere Hardy, Etude, Trembita, Bere Ardanpon, Vyzhnitsa, Bere Bosch and others.
But there are varieties that should be avoided if the scab information scared you, and you do not want to watch it in your garden. Varieties susceptible to the disease: Winter Ligel Bere, Sapezhanka, Forest Beauty and Bergamot Mliievsky.
What is pear scab
This nuisance is caused by microscopic pathogenic fungi and bacteria that remain for “wintering” in the garden in fallen diseased leaves or on branches of fruit trees. The external signs of this dangerous infectious disease include the following:
- Peeling of the skin.
- The appearance of spots. They will be large if the infection occurred in early spring, or small in case of a later infection.
- The appearance of ulcers and warts on all parts of the tree (up to the fruit).
On a note! If the weather was rainy on the eve of the harvest, then a late scab on the pear is possible, which is visually almost invisible. It can appear only at the storage stage (that is, spots will appear already in stock).
20-22 days after the buds open, the first signs of the disease can be easily detected on the tree with the naked eye.
Scab shoots
The shoots (especially young ones) are the first to take a “painful blow”. Swelling appears on the cortex, as a result of cracking of which a large amount of olive-colored spores can be seen with the naked eye. The bark becomes rough and begins to peel off.
Affected Leaves
The leaves are the following, taking the disease upon themselves: on their underside, olive-colored spots with a velvety coating form, which is nothing more than a plantation of fungal spores. The foliage dies and falls as it is damaged, thereby weakening the tree and disrupting its water balance (and this, in turn, has a very negative effect on fruiting not only this year, but also next).
Flowers and ovaries affected by scab
If spring was rainy, then the first signs of the disease will appear very early: already on the flowers and formed ovaries. The disease manifests itself in small dark spots covered with spores of fungi. The ovaries affected by the disease cease to exist: this, in turn, can lead to the loss of almost the entire crop.
On a note! The opinion of those who believe that the falling of the ovaries is caused only by bad weather conditions is erroneous.
Fruits disfigured by the disease
Fruits can become ill with scab at any stage (both at the beginning of fruiting and at the end of the season). A sign of the disease is the formation of gray-black spots (sometimes framed by a light rim) of a round shape, the size can vary (sometimes they can merge with each other and cover a significant part of the fruit). Affected by the scab, the fruit stops growing, its tissue hardens, it acquires an ugly shape and falls to the ground.
On a note! If the lesion occurred in the later stages of maturation, then spots can appear during storage, which subsequently crack and pathogens penetrate into them.
Causes of the disease
There are a number of factors leading to the appearance of scab on a pear:
- High degree of soil moisture. The presence of moisture is a prerequisite for the development of scab. In spring, water is formed as a result of melting snow, and in summer as a result of rain, growth and fog.
- Very dense landing of fruit crops. Spores are very quickly transmitted from one tree to another.
- Genetic uniformity (when plants of the same species are quite closely adjacent to each other).
Advice! We strongly recommend planting nearby trees of various types. For example, you can plant a plum next to a pear: there is a chance that the scab will not infect a neighboring tree. If you planted several pears in the homestead area that are in close proximity to each other, then infection of all trees (if there is one diseased) with scab is just a matter of time.
- Wrong variety selected. It is more advisable to choose scab resistant varieties (especially since breeders are always working in this direction).
Agrotechnical measures to combat the disease
Now you own information about what a scab on a pear. How to deal with it, we will tell further.
Agrotechnical measures:
- We collect the fallen fruits, we burn the fallen leaves.
- Using the secateurs, we remove the affected shoots and burn them.
- We keep the trunks in perfect purity: weed out the weed grass and also burn it.
- In late autumn and early spring we dig the soil under the trees.
- After autumn cultivation, we feed the earth with a solution of urea (7%), nitroammophos (10%) or ammonium nitrate (10% solution). In addition to nutrition, the destruction of pests and pathogenic microflora occurs.
- In early spring, without fail, we carry out sanitary and thinning crown pruning.
- Throughout the growing season, we carry out a visual diagnosis of trees in our garden: we immediately remove the leaves and fruits that cause suspicion.
- We periodically feed (foliar) potash and phosphorus-silicon fertilizers.
Chemical treatment of trees
The fight against pear scab involves chemical treatment in addition to agricultural activities. Such drastic measures are resorted to when other methods no longer help. We carry out treatment in several stages:
- First stage. We spray fruit trees with Bordeaux liquid (3%) in the green cone phase (i.e. before flowering).
- Second phase. In the phase of the pink bud (just before flowering), we spray, for example, using the “Skor”, “Tsineb” or “Khom” means in the proportion of 2 grams of the preparation per 10 liters of water.
- The third stage. We carry it after all the petals have fallen, and the leaves of the pear are coarsened. We process colloidal sulfur or other means having a similar effect.
Important! We recommend all spraying during the summer season at intervals of 2.5-3.5 weeks. The exception is periods characterized by increased humidity: in this case, we increase the number of treatments (up to 5-6 pieces).
Pear scabs can be avoided altogether if you adhere strictly to all our recommendations.