Pomegranate Leaf Curl: Why Pomegranate Tree Leaves Are Curling
If you’re lucky enough to grow pomegranate trees where you are, you may occasionally see leaf curling. Find out why the leaves curl on pomegranates and what you can do about it in this article.
Pests That Cause Pomegranate Leaf Curl
Small, sucking insects are a common cause of curling pomegranate leaves and include:
These insects feed on the sap in the leaves, and as they remove the sap, the leaves curl. The little insects also secrete a sweet, sticky substance called honeydew, which quickly becomes infested with black sooty mold. If your pomegranate tree leaves are curling, look for spots of black sooty mold to determine whether these insects are the cause.
In a healthy environment where you haven’t used insecticides, there are a number of natural enemy insects to keep the small pest insects in check, so the damage will be minimal. Toxic insecticides are much more effective against the beneficial insects than against the pest insects. As a result, toxic insecticides make problems with whiteflies, aphids, mealybugs, and scale insects even worse.
If you don’t have enough naturally occurring beneficial insects, you can buy them for release onto your pomegranate tree. Good choices include lacewings, lady beetles, and syrphid flies. If they aren’t available locally, you can order beneficial insects on the Internet.
Another control option is to spray the tree with horticultural oils, insecticidal soaps, or neem oil. These insecticides aren’t as harmful to the natural enemies and do a good job of controlling pest insects if you catch them while they are young. The drawback is that they only kill insects when they come into direct contact. You’ll have to coat the leaves completely and reapply a few times to get the pests under control.
Another insect that causes pomegranate leaf curl is the leafroller. These insects are moth larvae that roll themselves up inside leaves and then secure them with silk webbing. They are heavy feeders, and they can completely defoliate a tree if there are enough of them. They have several natural enemies, including tachinid flies, which are available commercially. It is hard to spray leafrollers with insecticides because they are hidden inside the leaves. You might have success with Bacillus thuringiensis (Bt), which sticks to the leaves and kills the caterpillars when they eat the leaves. Bt isn’t harmful to birds that eat the caterpillars.
Other Reasons for Curling Pomegranate Leaves
Additionally, if there is a deficiency of calcium, ammonium, or magnesium, this might cause the leaf tips to turn brown and curl sharply downward. If the tips of the leaves discolor and curl into a hook shape, try using a fertilizer that contains micronutrients. If the fertilizer doesn’t solve the problem, your cooperative extension agent may be able to help you diagnose the deficiency.
Pomegranate Tree Problems
Pomegranates (Punica granatum L.) include more than 500 known cultivars and produce medium-sized, leathery fruits containing tangy, juicy berries. Pomegranates grow in U.S. Department of Agriculture plant hardiness zones 7 to 11. The trees are relatively easy to grow and maintain, notes Clemson University Extension, but they are susceptible to fruit rots, mold, pests and wood damage. Pollination failure and inadequate sunlight may keep pomegranate trees from producing flowers and fruits.
How To Plant Pomegranate in a Pot
Choose a dwarf pomegranate variety like "Nana" which will grow to about 1 meter only,
suitable for growing in containers.
- The pomegranate root system is less than 60 cm (2 ft) deep, however, it can be 90 cm (3 ft) for very large mature trees. So the pot should be at least 60 cm deep.
- To grow pomegranate tree in a pot, you will need at least 50 liter (13 gallon) size container, the larger the better.
- The pot can be moved indoors during extreme cold and frost.
Mulch the plant with a 3 inch layer of sugar cane mulch. This will hold moisture in the soil.
- Prolonged water restriction can cause leaves to fall prematurely.
- Water frequently during growing, flowering and fruiting time. However, water the plants less during the winter months when the plant become dormant.
- Irregular watering may cause many problems.
- If the watering is not regular and even during fruit development, will cause the fruits to split.
- Avoid too much water, just water until the soil below the mulch becomes wet.
- Too much water can encourage development of fruit-splitting fungus.
Hand Pollination of Pomegranate Flowers
- You can pollinate the flowers by using an artist paint brush to transfer the pollen from the male stamen to the female ovary.
- Inadequate sunlight may also cause the lack of fruit production.
- Protect your pomegranate tree from too cold temperatures to avoid dropping of flowers.
- The pomegranate trees generally start bearing fruit from the second or third year.
- The pomegranate tree fruits during March to May in Southern Hemisphere and from September to February in Northern Hemisphere .
- Once the fruit is formed, it takes 6-7 months to mature.
- Fruit fly traps can be put near the tree.
- The fruit is ready to harvest in autumn to winter. Pick the biggest and the brightest fruits first.
- The ripe pomegranates can be stored in a dark, cool place or the fridge for a couple of months.
- Note that the pomegranates do not ripen after you pick them unlike other fruits such as banana, mango and guava. The overripe pomegranates will split open on the tree. So pick the pomegranate fruit at the correct ripeness.
- The pomegranate is ripe and ready to eat if it has grown to its full size and the skin becomes firm and heavy. The color may be an indicator for its ripeness. The skin of the ripe fruit becomes red or deep red, however, the color varies from cultivars to cultivars.
- When you open a pomegranate, you will find bright red seeds with white or brownish pith on opening a good ripen pomegranate. But if the seeds appear brownish and soft, that means it is bad and not good for use.
Pomegranate Fruit Splitting
- Many times pomegranates split. What is the reason of this fruit splitting? This may be due to two reasons:
- Irregular and uneven watering as mentioned above.
- Fungal disease at the time of fruit ripening can split the fruits.
Pomegranate Tree Diseases
- Fungal diseases can cause leaf spots, flower drop, premature leaf drop, fruit splitting and fruit rot. Spray copper fungicide when the fruits begin to grow.
- Insects like aphids, whiteflies, mealybugs and scale will cause of curling pomegranate leaves.
- To control insects on tree, spray the tree with neem oil.
Pomegranate Tree Fertilizer
- Do not fertilize pomegranate tree during the first year. Apply a thck layer of compost or aged manure as mulch. You can feed plant with compost tea or a liquid fertilizer every 3 weeks.
- Too much fertilization can lead to excessive leaf growth and premature fruit drops.
- A fertilizer of N:P:K (nitrogen, phosphorus and potassium) 10:10:10 is good for pomegranate trees.
- A deficiency of calcium, ammonium or magnesium may cause the leaf tips to turn brown and curl into a hook shape.
Pruning The Pomegranate Tree
- When your your pomegranate tree is about 3 feet tall, trim its branches by about a third to encourage new growh.
- Regular pruning of the pomegranate tree will ensure good harvest.
- Prune out suckers growing at the base and inward branches at the middle to prevent over-crowding.
- While pruning note that the pomegranates flower on new growth and bear fruit on branches that are 2 or 3 years old.
- To keep fruiting wood coming, each year remove suckers, dead wood and some of the oldest stems to stimulate new growth.
- Prune only lightly, heavy pruning reduces fruits.
- Winter or early spring is the best time for pomegranate tree pruning before the start of new growth.
How To Use Pomegranate?
The pulp of ripe pomegranate is eaten along with its seeds, and also used as its juice juice, smoothie, in baking, cooking, garnishing and alcoholic beverages.
Watch How to propagate pomegranate YouTube video
When to Spray Pomegranate Trees
Look for wilting, discolored or falling leaves on your pomegranate tree, indicating a potential pest problem. The most common suspects for pomegranate pests are white fly, mealy bugs, thrips and scale insects. Treat insect problems with a neutral copper insecticide spray or a pesticide, following label instructions carefully. Neutral copper spray is considered safe for use on vegetables and fruits but you should always read the label carefully. Spray again in 30 days to treat any pests that may have hatched and prevent re-infestation.
Investigate yellow or curled leaves, or brown spots on otherwise healthy pomegranate leaves as they appear. Caused by the fungus Cercospora, leaf fungus is a likely cause in hot, humid conditions. Remove infected leaves from the tree, and spray with a fungicide.
Remove all rotting and infected pomegranate fruit from the tree as they appear, and spray with a fungicide to control the Phomopsis sp. fungus.
Apply nutrient sprays twice in the early summer, approximately 30 days apart. Zinc, iron or magnesium deficiencies are occasionally a problem in pomegranate trees., usually caused by alkaline soils. Common symptoms include chlorosis or yellow leaves, which then drop. Iron deficiencies usually affect the youngest leaves while zinc and magnesium deficiencies affect older leaves. Apply a zinc spray during the dormant season, or spray the foliage in the spring and early summer. Iron chlorate and a balanced acid fertilizer applied to the soil will solve iron and magnesium deficiencies. Additionally, the "International Journal of Agriculture & Biology" reported that foliar application of zinc sulfate, iron sulfate, manganese sulfate and boric acid increased yields of fruit and juice.
An occasional adult leaffooted bug on fruit is tolerable, but numbers should not be allowed to build. Remove all fruit before winter to decrease the number of overwintering bugs. Native egg parasites, such as Gryon pennsylvanicum, if not disrupted, also help keep numbers down. Outbreaks, especially in late summer or fall before harvest, should be treated quickly, before serious damage can occur.
The egg parasite, Gryon pennsylvanicum, provides partial to good control of leaffooted bugs, especially if host numbers are high. Eggs with round exit holes indicate presence of the parasite.
Remove all fruit before winter to reduce the number of leaffooted bugs overwintering in an orchard. Cleaning debris from near the orchard may also help. Cold temperatures near 21°F (-6°C) will kill some exposed bugs, while those protected from winter weather survive better. If possible, remove other nearby overwintering hosts such as juniper. It is not known if efforts to reduce leaffooted bug populations after harvest has a direct benefit to the pomegranate orchard the following August. However, winter sanitation in pomegranates is very important in pomegranate orchards next to preferred spring hosts, such as almonds.
Organically Acceptable Methods
Where possible, manage leaffooted bugs in neighboring crops to prevent migration into pomegranate. Use cultural controls to reduce overwintering numbers. Pyrethrins may kill some nymphs but control efficacy varies.
Monitoring and Treatment Decisions
Leaffooted bug outbreaks occur areawide so if problems are observed in almonds or pistachios, also look for them in pomegranates. Be wary after mild winters, or if high numbers were found the previous fall. Scout orchards for individual adults or masses of nymphs on fruit from mid-August through October. Higher numbers will be found closer to harvest.
There are no treatment thresholds for leaffooted bugs in pomegranates.
|Common name||Amount per acre||REI‡||PHI‡|
|(Example trade name)||(hours)||(days)|
|Pesticide precautions Protect water Calculate VOCs Protect bees|
|Not all registered pesticides are listed. The following are ranked with the pesticides having the greatest IPM value listed first—the most effective and least harmful to natural enemies, honey bees, and the environment are at the top of the table. When choosing a pesticide, consider information relating to air and water quality, resistance management, and the pesticide's properties and application timing. Always read the label of the product being used.|
|(Belay)||4–6 fl oz||12||7|
|MODE-OF-ACTION GROUP NUMBER 1 : 4A|
|COMMENTS: Do not apply during bloom or when bees are actively foraging.|
|(Lannate SP)||1 lb||48||14|
|MODE-OF-ACTION GROUP NUMBER 1 : 1A|
|COMMENTS: Disruptive to natural enemies of mealybugs, caterpillars, soft scales, aphids, and other pests. Use of this pesticide may result in outbreaks of these pests. Methomyl is also toxic to bees and should not be applied when bees are actively foraging.|
|(PyGanic EC 1.4)#||2–4 pt||12||When dry|
|MODE-OF-ACTION GROUP NUMBER: 3A|
|‡||Restricted entry interval (REI) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (PHI) is the number of days from treatment to harvest. In some cases, the REI exceeds the PHI The longer of two intervals is the minimum time that must elapse before harvest.|
|*||Permit required from county agricultural commissioner for purchase or use.|
|1||Rotate chemicals with a different mode-of-action group number, and do not use products with the same mode-of-action group number more than twice per season to help prevent the development of resistance. For example, the organophosphates have a group number of 1B chemicals with a 1B group number should be alternated with chemicals that have a group number other than 1B. Mode-of-action group numbers ("un"=unknown or uncertain mode of action) are assigned by IRAC (Insecticide Resistance Action Committee).|
|#||Acceptable for use on organically grown produce.|
UC IPM Pest Management Guidelines: Pomegranate
UC ANR Publication 3474