Avocados have developed throughout history in different colors, shapes, and characteristics, ultimately reaching the current era, dominated by the Hass avocado.

However, as Mary Lu Arpaia, cooperative extension specialist, subtropical horticulture from UC Davis explained during her presentation at the 8th Avocado Congress of Jalisco, germplasm and paradigm shifts are key to the future of the avocado industry.

She said avocado traders must not be satisfied with the present, and should always be looking forward. 

Plant improvement

Avocado trees have been improved throughout history, especially during the modern era when they have gained so much popularity. 

"Plant improvement requires someone to imagine the future, and what can be an improvement over what we have," Arpaia said. "It involves being very observant, so the selection and breeding process is key to the future of avocados."

History

For the last 100 years, the industry has been dominated by two varieties, the Fuerte, which originated in Mexico and was taken to California in 1911. By 1920, it was the dominant variety in the state. 

Throughout the next few decades, a wide array of commercial varieties were developed. 

The Hass seed was planted in 1926 and developed, later becoming dominant from the 1970s forward. 

"Rudolph Hass observed the eating quality and tree firmness of Hass and patented the variety in 1935. It was the first avocado variety to be patented in the United States," said Arpaia. 

The variety has less alternate bearing, tolerates heat better, and has great fruit quality with fewer post-harvest problems, even better than Fuerte.

Currently, over 90% of the avocado acreage in California is planted with Hass.

Progress

Throughout the years, even with the domination of Hass, scientists and breeders in California like Bob Berg have worked tirelessly to improve the genetics of the fruit. 

Varieties like Gwen, Lamb Hass, and Luna have all been released since then, taking the best aspects of Hass and improving on them.

In South Africa, the Maluma variety was developed in the early 2000s which according to Arpaia, is also a "revolutionary variety in many aspects."

Future avocado varieties

Arpaia said it's hard to narrow down what the ideal avocado is. However, it has to do with the eating experience, including the smoothness and creaminess the fruit offers. Regarding horticultural characteristics, she found fruit quality, yield efficiency, productivity stress tolerance, and management stand out. 

"When you are deciding to grow, you have many decisions to make, including where you are going to plant, what variety, what rootstock, all to optimize productivity so you have the best possible fruit to send to the consumer," Arpaia said. 

Part of the decision is also thinking about post-harvest fruit performance, because "because 'we live in a global economy, and fruit must be able to endure a boat or truck ride for 3-5 weeks."

Arpaia said this was one of the traits that older varieties lacked, so looking forward, that is a very important trait to have. 

Arpaia's avocado breeding program in California is treating trees like factories, where the final outcome is the fruit. With this, they control a variety of variables and raw materials that go into growing the tree to optimize productivity as much as possible. 

The leaves of the tree, she said, are the backbone of the tree because they are where photosynthesis occurs, producing the raw materials that feed fruit growth, vegetative growth, and more.

Arpaia pointed out that improvements for avocado trees will come from bettering tree size and structure, improved bearing, stress tolerance, pest and disease resistance, and adaptation to climate change.