How should pear trees be planted to grow evenly without an off year?
Like other trees, pear trees often have an alternate bearing pattern of a heavy crop one year and a light crop the next. The causes of this uneven yield from year to year are: first, improper regulation of fertilizer and water, causing an imbalance in soil nutrient supply, or excessive nitrogen fertilizer causing excessive vegetative growth; second, too heavy a crop in the on year, which weakens flower bud formation for the following year; third, overly profuse flowering in the on year, producing large amounts of gibberellin, which inhibits flower bud differentiation for the following year; fourth, freezing damage killing some flower buds; fifth, drought and waterlogging disasters causing large numbers of flower buds and young fruit to drop.
To prevent pear trees from having an off year and to promote balanced growth, high and stable yields, the following points should be carried out well in preventive measures.
The root system of pear trees has two growth peaks, one from late May to early and mid-June, and the second from September to November. To make the root system well developed and vigorous, organic fertilizer must be applied generously in combination with deep digging of the soil around the roots, along with phosphorus and potassium fertilizer. The digging depth should reach 50 cm. Only when the soil has sufficient nutrients can the roots be well nourished and protected.
After the new leaves unfold in spring, nitrogen fertilizer should be the main topdressing, with a multi-element compound fertilizer added in June, and from July to August, combined with pest and disease control, urea and potassium dihydrogen phosphate should be sprayed on the leaves 2-4 times. In this way, nutrient supply can be ensured in a balanced manner, and the level of flower bud differentiation can also be improved.
The tree vigor of fruiting trees should be kept neither too vigorous nor too weak; the branch groups on the whole tree should be kept young, with medium and small branch groups accounting for 90%, medium and short branches robust, and new shoots on the outer part of the canopy 30-40 cm long. When flowering and fruiting, weak buds and weak flowers should be thinned first. Thirty days after flower drop, the fruit generally no longer drops. At this time, diseased and insect-damaged fruit, deformed fruit, and stunted fruit should be thinned so that the pear tree's yield remains at the average level of ordinary years.
During the growing period, the soil in the pear orchard should be kept supplied with water for bud break, water after flowering, water to promote fruit growth, and water in autumn and winter. If water is insufficient, drought resistance should be carried out in stages. At the same time, large drainage ditches should be dug around the pear orchard to prevent waterlogging damage. In pest and disease control, the main targets are pear rust, pear scab, red spider mite, pear psyllid, leafminer, and pear fruit borer.