How to control excessive growth in strawberries? Introduction to commonly used growth-regulating chemicals

Right now is the time when strawberry seedlings are growing rampant, and many strawberry seedlings have basically filled out. If excessive growth is not controlled in time, excessive vegetative growth will lead to insufficient reproductive growth, producing a large number of runners and affecting yield. So how do you control excessive growth in strawberries? What chemical can control excessive growth?

Why do strawberries need growth control?

The main purpose is to keep the aboveground strawberry petioles from over-elongating and the leaves from becoming too thin and too large, to reduce the space occupied by the strawberry plant, so that the aboveground part of the strawberry seedling is compact, the leaves thicken, the petioles become sturdy, and the root system develops well. This is beneficial for ventilation and light penetration and improves the disease resistance of the strawberry plant. By controlling excessive growth, the balance between vegetative growth and reproductive growth of strawberries is regulated, flower bud differentiation is advanced, and strawberries bloom earlier and bear more fruit.

Conditions for growth control:

Growth control can be carried out once the seedling emergence rate in the seedbed reaches more than 70%.

Measures for growth control:

Orchard management techniques

1. Control water and reduce quick-acting nitrogen fertilizer. Water frequently in small amounts to meet the growth needs of strawberries while lowering soil moisture. Control the amount of nitrogen fertilizer used; it is recommended not to use any form of nitrogen fertilizer at this stage.

2. Nutritional regulation. Spray phosphorus and potassium fertilizer on the leaves to achieve balanced fertilization of nitrogen, phosphorus, and potassium. This can both balance the nutrients within the strawberry plant and promote flower bud differentiation.

3. Shallow hoeing to cut roots or intertillage weeding. When the plant grows too vigorously, the “shallow hoeing method” or intertillage can be adopted. On one hand, it can increase soil aeration; on the other hand, it can break some roots, which is beneficial for the downward growth of secondary roots.

4. Foliar spraying of triazole fungicides. Such as imibenconazole and difenoconazole, etc., can effectively reduce the occurrence of strawberry diseases, and can also use the growth-inhibiting property of triazole fungicides to control the vegetative growth of strawberries.

In terms of chemical use:

Method one:

First growth control: in early July, if the seedling emergence rate in the seedbed has reached more than 70%, the first growth control can be carried out, controlling only the mother seedlings.

Second growth control: from late July to early August, carry out growth control across the whole field, together with the use of a strawberry flower bud differentiation program.

Method two:

When the seedling emergence rate reaches more than 70%, dig out the old seedlings and let the first-generation seedlings continue to send out runners from the mother seedling position. After the runners have grown well, carry out growth control across the whole field between late July and early August, together with the use of a flower bud differentiation package.

Method three:

The dosage of paclobutrazol and uniconazole is difficult to master. If the dose is too light, it will not control growth; if the dose is too large, by the time you see that growth has been controlled, the strawberry growth point is blocked and no longer grows, and even after transplanting to the field, it will not recover for a long time. This causes blocked flower bud differentiation and an increase in deformed fruit. From the analysis of the properties of the chemicals, paclobutrazol acts slowly and has a long residual period. Uniconazole acts quickly and has high activity, and compared with paclobutrazol, its residual period is shorter and it is relatively safer.

Method four:

The use of azole fungicides in strawberry seedling cultivation can both prevent disease and inhibit the growth of strawberry plants. It is generally recommended to begin use in July, starting when the number of seedlings reaches about 60%-70%, using a small dose in the early stage, which can both prevent disease and achieve the purpose of controlling growth and strengthening seedlings. After mid-July, as temperatures rise and rainfall increases, strawberries enter their peak growth period, and the dose can then be increased somewhat. For example, Yulong Wenshou (trifloxystrobin + tebuconazole) can be used in the early stage at 5 grams mixed with 15 kg of water, and in the later stage at 10 grams mixed with 15 kg of water for spraying.