Caring for your Avocado Tree Part 2: Diseases and Pests

Between homemade smoothies, skin care, and good old-fashioned guacamole, who doesn’t love a fresh, ripe avocado?

As much as we all wish that avocado trees could be a plant it, forget it, and harvest affair, caring for your tree requires consistency and vigilance. The health of your tree can and often does have a huge impact on your harvest during fruit-bearing season.

Here’s an overview of some of the most common diseases and pests that avocado tree owners have to be on the lookout for.

Diseases & Conditions

Sunblotch

Avocado trees that have been hit by sunblotch are often stunted in growth, discolored in the twigs and the bark, and, perhaps most importantly, yield discolored fruit. Even in situations where the tree doesn’t show a lot of symptoms, it’s not unusual for the annual yield to go down dramatically.

Treatment Options: Because sunblotch can’t be cured, tree owners have to focus on preventing it from spreading. Pruning tools need to be sanitized in bleach if they’ve been used on a sunblotch-infected area and if you can, using separate and uncontaminated tools for healthy trees is ideal. In situations where a single tree is at issue, it’s sometimes recommended that you destroy the infected tree to prevent spread to the others.

Cankers

You don’t have to be a tree whisperer to see when a tree is suffering from cankers. Not unlike a boil or a sore on human skin, trees with this condition often take a sunken appearance with sap and gum often dripping from the exposed areas. This may be merely unsightly if it’s just branches and trees affected, but if cankers develop in the trunk, this is a condition that could potentially kill your tree.

Treatment Options: Cankers require a multi-faceted approach to treatment. Pruning and removing dead and dying branches below the area that’s been infected is a good start along with being careful to seal the pruning cuts. To address the bacteria causing the cankers, fungicides are often highly recommended.

Fruit Rot

This is considered a fungal infection of the tree that usually happens as a result of unsanitary conditions and sometimes even from fruit that hasn’t been harvested quickly enough. You can tell when a tree is suffering from fruit rot when the fruit is wrinkling, showing brown spots, and falling before ripening.

Treatment Options: To salvage an avocado tree that’s infected with fruit rot, it’s recommended that tree owners remove the infected areas of the tree as soon as possible.

Common Pests

Mites

These pests aren’t always easy to spot visually, but the damage they do to leaves is undeniable. For those who are wondering why the falling leaves are considered such a big deal, it’s because the leaves are important to protecting the fruit from the damaging sun rays. If allowed to go unchecked, mite populations are capable of growing rapidly.

Treatment Options: The introduction of predator mites is one solution that’s available to tree owners, but the most effective treatment for mites is specialized horticultural oil.

Caterpillars

As it turns out, the popular image of caterpillars chewing through apples has a strong basis in reality. These creatures go after flowers, leaves, and fruit, and if they’re given free reign, they’re capable of destroying an entire avocado crop in practically no time at all. The speed at which they operate is a big part of what makes a caterpillar infestation particularly dangerous to your tree.

Treatment Options: Caterpillars can be treated with a bacterial spray called Bacillus thuringiensis. By taking care to spray the leaves and the insides of any buds, you can stop a caterpillar infestation dead in its tracks.

Thrips

This is a condition that results in scarred avocados and stunted growth depending on how serious the condition becomes. You will normally see these pests come during the earlier part of the season because they like to feed on growths and shoots while they’re still young and tender.

Treatment Options: Thrips try to seek moisture so stopping an infestation ultimately comes down to a combination of repelling the population on the avocado tree and removing alternative hosts. To combat thrips, it’s ideal for tree owners to pull out any grass or other plants near the avocado tree and to also apply a pesticide or oil and fat-based soaps designed to kill harmful insects.

Signs That Your Avocado Tree Could Have a Disease or Pest Problem

So we’ve talked about common diseases and pests that are capable of doing serious damage to an avocado tree. What a lot of these conditions have in common is the simple fact that if you catch the problem early, you have a much better chance at salvaging your tree.

Are there any signs to look out for? Is there some way to know if you should be suspecting a pest infestation?

Here’s a non-exhaustive list of symptoms to watch for:

• Premature leaves dropping
• Wilting leaves
• Lowering fruit production and cankers
• Poor growth
• Yellow or red streaks on the twigs
• Bark that’s peeling or cracking easily
• White powder on bark
• Mushrooms at the tree base
• Brown spots or scarring on avocados

If you notice any or all of these occurring, it could mean that there’s a problem with the tree that requires further investigation.

Can You Save or Protect Your Avocado Tree From Pests or Disease?

The good news is that many of the conditions mentioned here can be managed and actively protected against with a strong regimen of pruning, careful containment of problem areas, and fertilizer.

Whittier Fertilizer has two products that will not only help your tree grow but will also promote higher yields in its Grow More Citrus & Avocado Organic Fertilizer and its GreenAll Citrus and Avocado Food. Both of these products are organic, consistent, and go a long way toward promoting and preserving the health of your avocado tree.

If you have an avocado tree, you’re in a better position than most to enjoy avocado-based sandwich spreads and chip dips all year-round. Protecting your tree’s health is essential to keeping those harvests healthy and plentiful.

Consider contacting us today if you have any questions.