What Causes Shoot Dieback in Pomegranate Trees? Detailed Prevention and Control Measures

The pomegranate tree is relatively common, especially in winter and early spring, when young shoots are highly prone to frost injury, and in spring they are highly prone to dehydration, drying up and dying, which seriously affects the flower bud differentiation of pomegranates and deals a severe blow to yields. So what causes pomegranate shoot dieback? Let's take a look together with the editor.

I. Causes of shoot dieback

Shoot dieback in pomegranate branches rarely occurs in winter; it generally occurs in early spring, when the branches develop longitudinal wrinkling of the bark, spreading from the upper part of the branch downward, resulting in the death of the branch from top to bottom. Moreover, when early spring is dry, combined with frequent dry northwest winds, shoot dieback is relatively severe; conversely, shoot dieback is relatively mild. The real cause of shoot dieback is freeze-drought. In northern regions, winters are cold; in winter and early spring the underground soil freezes, and the root system of young trees, which is distributed shallowly, is mostly in the frozen soil layer, so the roots cannot absorb water or absorb relatively little water. In early spring the temperature rises quickly, and the wind is strong and the air is dry, so branch moisture is lost quickly, while the root system cannot supply enough water to keep up, causing an obvious water imbalance; this causes physiological drying of the branches, thus causing shoot dieback in the branches.

II. Prevention and control measures

1. Variety selection

When planting, you should choose varieties with relatively strong cold resistance, such as Hongpitian No. 1, Heizitian, and Qingpitian No. 1. In addition, when planting you should also consider the local climatic conditions; for example, when planting in the north, it is not advisable to plant varieties with poor cold resistance, as this is not conducive to their overwintering.

2. Strengthen fertilizer and water management

For young trees planted for 1-2 years, phosphate and potassium fertilizer should be applied in a timely manner during the growth period from July to September each year, nitrogen fertilizer application should be controlled, and the number of waterings should be appropriately reduced, so as to inhibit new shoot growth and allow the branches to fully lignify; in this way they can better resist low-temperature freezing injury as well as dry winds.

3. Timely pinching

In mid-August, promptly pinch off the growing points of new shoots to control branch growth and promote nutrient accumulation. At the same time, promptly remove the young buds sprouting at the pinched points of the branches, to ensure the branch tissues fully mature and enhance the plant's overwintering cold resistance.

4. Chemical cold protection

In early August, spray a 300-fold solution of paclobutrazol on the leaves to control new shoot growth and promote branch fullness. In November, after the plant sheds its leaves, apply petroleum jelly to the new shoots of the branches; this can improve the plant's cold resistance. In February to March of spring, spray the tree canopy with 5% lime milk; this can delay the active period of the branch cambium and reduce transpiration water loss from the branches.

5. Burying in soil for cold protection

For planted seedlings, in early November the young tree branches can be bent down and buried in soil to prevent the branches from losing water and freezing. The burial depth is about 30 cm, and the branches are released again in early March of the following spring.

The above introduction to the causes of pomegranate tree shoot dieback and prevention and control measures is hoped to help you. To learn more related knowledge, please stay tuned to us.