Avocado Tree (Persea americana)
The Avocado tree provides one of the most important fruit crops of Tropical America. Three major types were prevalent among pre-Columbian peoples - classified as Mexican, Guatemalan and West Indian races. These races originated in Southeast-Central Mexico and Guatemala around 8000 to 7000 B.C. By the time of the conquest of the Americas, edible avocados were found throughout Central and northern South America, with the Mexican and Guatemalan races prevalent at higher elevations from Central Mexico to Costa Rica, and the West Indian race found near sea level throughout Central America.
West Indian avocado trees now dominate the coastal lowlands of Central and South America, and the Caribbean. Here in Florida, West Indian avocados were crossed with Guatemalan types to create strong and productive hybrids that provide the foundation of home landscapes and commercial orchards of our communities. Thus, with the potentially lethal laurel wilt fungus knocking upon our door, we have been understandably distressed with regard to the avocado.
The laurel wilt fungus may or may not be a new introduction to the sunshine state, but the beetle that carries the disease from one tree to another most certainly is. We have watched as this beetle and the disease that it spreads has caused widespread death of one of our cherished native Everglades trees, and also quick death for many back-yard avocado trees to our immediate north. As yet; however, Miami-Dade and Broward counties have not experienced any widespread losses due to this disease.
For the homeowner and the commercial avocado grower the question must be asked. Should I, or should I not plant an avocado tree? The answer lies in your level of acceptable risk and in no small part in the importance that one places on this Florida favorite. I for one will plant an avocado tree this weekend – to do any less would be tantamount to the acceptance of defeat. She (the avocado) deserves better.
Regardless of your stance on risk, there are some tangible actions that one can take to reduce the dangers of laurel wilt. Avocado trees should be kept healthy and vigorous, for the unthrifty tree will be a more likely target for the beetle. Proper watering, fertilization and care should become a priority. The avocado should be pruned each year to control size and maintain vigor, but after pruning the branches should be removed from beneath the canopy. The decaying branches give incentive to the opportunist beetle, which may then enter into the tree and infect it with the disease.
The threat of sudden death may also provide a needed push for the removal of that old and decrepit avocado tree that many of us have in our home gardens. You know the tree - the one that suffered at the hands of the storms and has never really recovered. It grows a bit each year, but it never really thrives and its fruiting is always disappointing. It is time to remove it. Do not wait for a disease to make your decision.
What variety Avocado Tree should I plant in its place? This rests wholly with you. There are avocados for all seasons, from late May till February. No other fruit offers such an extended season. Colors range from green to red or purple and the skin from thin to woody, smooth to rough and pebbly. Some of our old standards, like the ‘Simmonds’ and ‘Choquette’ remain a good choice for the homeowner, but increasingly varieties like ‘Donnie’ and ‘Miquel’ may offer what is needed in the home landscape. A new generation of avocados from Central America, with bold colors and shapes wait in the wings. These new choices are under field testing here in Florida and will soon be available for all to enjoy. Some, like the seedless ‘Esparza’ from Costa Rica, was lost since the 1950s. Now it is found and offers something completely new to the fruit grower.
As to care, the avocado is well adapted and forgiving in the home landscape. Ample watering and fertilization with a proper fruit tree fertilizer will provide nearly all that the tree needs. The tree cannot withstand flooding and even a habitually waterlogged soil will spell ultimate death. Pruning should be done each year as soon as the fruit have been harvested. We do not have any true dwarf avocado varieties, but with annual pruning the size and vigor of the tree can be maintained. A regular pruning program translates to a consistent and heavy production. There is no need to apply fungicides or insecticides, as a properly adapted variety will have good tolerance of pest and diseases.
We will have to wait and see if laurel wilt will be the end of our cherished avocado trees, the trees that provide a home for our orchids and bromeliads and stand in monument to our beloved. Yet, we must have faith in nature and the avocado to weather this storm. The glass remains half full at the writing of this article, and with a little luck we will be growing, harvesting and enjoying the West Indian avocado for years to come.
Avocado Tree Pruning Videos