How to Treat Leaf Curl on Cherry Trees? A Detailed Guide to Prevention and Control Methods

SummaryWater deficiency: When cherry trees develop leaf curl due to hot weather and lack of water, watering and appropriate shading can relieve it on their own. Aphids: If it is caused by aphids, pesticides such as imidacloprid need to be sprayed. Nutrient deficiency: If it is potassium deficiency, potassium dihydrogen phosphate can be sprayed, or potassium sulfate fertilizer can be applied to the soil; if it is calcium deficiency, calcium lactate, the calcium preparation GA calcium treasure, Meilin high-efficiency calcium, etc. can be used for control; if it is molybdenum deficiency, a 1.2% ammonium molybdate solution can be sprayed on the leaves for control.

I. Treatment Methods for Leaf Curl on Cherry Trees

1. Caused by water deficiency

There are many causes of leaf curl on cherry trees. Especially in summer, when the weather is relatively hot, cherry trees are very prone to leaf curl. If the leaf curl is caused only by water deficiency due to hot weather, simply watering more or providing appropriate shading can relieve the symptoms on their own.

2. Caused by aphids

Leaf curl on cherry trees may also be caused by aphids. Aphids generally like to gather on the underside of leaves to pierce and suck sap, causing the leaves to curl and wrinkle. When aphids occur, a 2000-fold dilution of 10% imidacloprid, or pyrethroid pesticides, can be sprayed for control.

3. Caused by nutrient deficiency

(1) Potassium deficiency: If cherry trees lack nutrient elements, leaf curl can also occur. Generally, potassium deficiency causes the leaf edges to scorch and wither, gradually spreading from the tail of new shoots to the top. From midsummer to late summer, scorching appears on the leaves of old trees. Sometimes the leaves turn blue-green, then the leaf margins curl parallel to the main vein, gradually losing green and appearing scorched. During the growing period, 0.2%-0.3% potassium dihydrogen phosphate can be sprayed, or potassium sulfate fertilizer can be applied to the soil.

(2) Calcium deficiency: If cherry trees lack calcium, the tips of the upper young leaves curl into a hook shape, and after a few days they turn brown-yellow and scorch. During this period, calcium lactate, the calcium preparation GA calcium treasure, Meilin high-efficiency calcium, etc. can be used for control.

(3) Molybdenum deficiency: If cherry trees lack molybdenum, the areas between the leaf veins will lose green, and in severe cases turn yellow. Yellow and orange spots of uneven size are likely to appear. The leaves become thin, long, and deformed, and the leaf edges curl upward into a cup shape, after which the leaf mesophyll falls off and becomes incomplete. During this period, a 1.2% ammonium molybdate solution can be sprayed on the leaves for control.

II. Control Methods for Aphids on Cherry Trees  

1. Trunk application of pesticide

2 parts water, 1 part 40% omethoate, and 1 part multi-functional plant synergist can be mixed and stirred to prepare a medicinal solution. Use a brush to apply a pesticide ring about 10 cm wide on the trunk for protection. If the bark is relatively rough, first scrape off the old cracked bark with a knife before applying the pesticide. After application, wrap it well with newspaper or plastic film.

2. Trunk injection

Use an iron awl to pierce holes diagonally from top to bottom on the main trunk of the cherry tree, deep enough to reach the xylem, then use a No. 8 syringe to inject 40% dimethoate, and seal the hole openings well. After waiting 2-3 days, 95% of the aphids can be killed.

3. Spraying pesticides

Commonly used pesticides include a 1500-fold dilution of 35% emulsifiable concentrate, a 3000-4000-fold dilution of 50% pirimicarb, a 1500-fold dilution of 50% phoxim emulsifiable concentrate, and a 1500-fold dilution of 40% omethoate, etc. To improve the control effect, an appropriate amount of spreader can be added to the solution. During this period, several pesticides should be used alternately to avoid using a single pesticide for control.

4. Protect natural enemies

The natural enemies of aphids include ladybugs, green lacewings, hoverflies, parasitic wasps, etc., all of which have a very strong inhibitory effect on aphids. Therefore, broad-spectrum insecticides should be sprayed as little as possible, and spraying should also be avoided during periods when there are many natural enemies. This helps protect natural enemies and uses them to eliminate aphids, helping produce fruit that is green and pollution-free.