The walnut tree has been planted for several years without bearing fruit and its leaves are turning yellow, what should I do?

At present the nut market, walnuts included, is doing well, and all kinds of processed walnut products are selling briskly, which has drawn quite a few people into the “ranks” of walnut growers. But many growers report that a walnut tree planted for several years does not bear fruit and its leaves turn yellow, so what should be done? Let us look below at what solutions there are.

I. A brief introduction to the walnut tree

1. The walnut tree is also called the Persian walnut, black walnut, and so on, and there are wild hickory walnuts and improved varieties produced by artificial grafting. It is cultivated and planted in all parts of our country, and among these the artificially improved walnut varieties are planted more, because the improved walnuts have large fruit, thin shells and high yields.

2. The height of the walnut tree is generally from two metres to ten metres, but there are also walnut trees that grow to more than ten metres tall. Its crown is relatively broad, the trunk changes from grey-green to grey-white as it grows, the leaf blades are dark green on the sun-facing side and light green on the back, and the leaf edges have fine serrations. The walnut tree generally blooms with yellow flowers in May, and bears fruit around October; the hard shell of a fresh walnut is also wrapped on the outside by a layer of green skin.

3. The walnut tree likes warm, moist sandy loam soil, and mostly grows on hillsides and hilly terrain. Besides the effects of prolonging life, strengthening the waist and essence, and moistening the intestines to relieve constipation, the fruit borne by the walnut tree can also be used as carving material; and its wood can serve as a superior material for gardens, road greening, furniture and military products.

II. What should be done if the walnut tree does not bear fruit?

If you want to solve the problem of walnuts not bearing fruit, you need to understand clearly which causes are responsible for the failure to bear fruit, so below we will talk in detail about the causes of walnuts not bearing fruit and how to solve it.

(1) Causes of walnuts not bearing fruit

1. Walnuts not bearing fruit caused by the choice of planting variety: today planted walnuts are basically grafted seedlings, and if seedling trees grown from selected seed are used for cultivation it may take ten years to bear fruit, and the quality of the fruit produced is uneven.

2. Walnuts not bearing fruit caused by a poor planting site environment and improper management: if walnuts are planted in poor, severely cold areas, and on top of that are managed improperly over the long term, such as unreasonable water and fertiliser application, improper pruning and so on, it will inevitably result in walnuts not bearing fruit.

3. Walnuts not bearing fruit caused by poor pollination and attack by pests and diseases: the fruiting of plants mostly goes through pollination, and if a problem occurs in the pollination step it will also affect fruiting; in addition, if the walnut tree has its nutrients destroyed by pests and diseases, or its flowers are pollinated, it also cannot bear fruit.

(2) Methods to solve the walnut tree not bearing fruit

1. Choose fine artificially grafted walnut tree varieties: such as the Xiangling walnut bred by hybridisation in Shandong Province, Guanhe No. 1, and Xinxin No. 2 bred in Xinjiang, as well as the Baokexiang bred in Beijing, and other high-quality walnut trees. Of course, the choice of varieties must be made according to the actual local environment and conditions; only by choosing the most suitable variety can the greatest benefit be obtained.

2. Plant the walnut tree in an environment suitable for its growth, and strengthen management: in terms of management, note that deep ploughing should be carried out reasonably in the three seasons of spring, autumn and summer, removing weeds from the orchard and spraying herbicide; moreover, nitrogen fertiliser and potassium fertiliser are also indispensable, topdressing should be done in the year of planting, and base fertiliser should be used each month according to the situation; the walnut is a plant that likes moisture, so during its growth the soil must not be allowed to become dry and short of water, and irrigation should be carried out in good time during its vigorous growth period, when flowering, when fertilising and when drought occurs.

3. Prune and shape the walnut tree: properly prune away densely growing, diseased, weak and excessively vigorous branches, which helps the other branches absorb nutrients and grow, and also helps flowering and fruiting.

4. Ensure pollination of the walnut tree: besides pollination under natural conditions, hand pollination can also be carried out; in addition, excess male flowers that grow can be thinned out, leaving the nutrients and water for the successfully pollinated female flowers to develop and set fruit.

III. What should be done if the walnut tree leaves turn yellow?

(1) Causes of walnut tree leaves turning yellow

1. Yellowing of leaves caused by iron deficiency in the walnut tree: the leaves of plants are green mainly because of the action of chlorophyll, and the synthesis of chlorophyll requires the participation of the iron element, so iron deficiency can also cause this situation.

2. Yellowing of the walnut tree leaves caused by the erosion of pests and diseases: the occurrence of pests and diseases can lead to malnutrition in the plant and thus cause the leaves to turn yellow.

3. Yellowing of leaves caused by soil that is not breathable and too heavy in clay: soil that is not breathable easily affects the respiration of the root system, and thus affects the tree's nutrient absorption.

4. Yellowing of walnut tree leaves caused by insufficient light: sometimes, without proper pruning of branches and leaves, some branches and leaves cannot get sunlight, and thus the leaves turn yellow.

(2) Methods to solve the yellowing of walnut tree leaves

1. Supplement the walnut tree with an appropriate amount of the iron element and the other fertilisers it needs.

2. Frequently loosen the soil around the walnut tree, or do not plant it in soil that is too heavy in clay, and also pay attention to the magnesium and manganese elements in the soil.

3. Prune the walnut tree regularly: carry out spring pruning between bud break and full bloom, carry out autumn pruning in September and October to strengthen the tree's vigour, and in summer after the flowers fall cut away the branches that grow too vigorously and do not bear fruit.

4. For trees affected by pests and diseases, take different measures according to the situation: for mild cases, cut away the diseased and pest-infested branches; for more serious cases, spray the corresponding pesticide.

So on the whole, the key is to manage well, choose good seedling varieties, apply enough water and fertiliser, plant in suitable soil and ensure light, and then there is basically no big problem. I hope the above introduction can help you.