Researchers at the Institute of Subtropical and Mediterranean Horticulture (IHSM) La Mayora have confirmed that in recent years, the flowering of the most marketed avocado variety worldwide, the Hass, has been advanced by climate change. In the study, carried out by researchers Iñaki Hormaza and Librada Alcaraz, there has been an analysis of data collected over the last 15 years. These show that the flowering of Hass avocados has been advanced by almost three weeks, from early April to mid or even early March.
According to Hormaza, this early flowering increases the chances for the flower to be exposed to cold or rainy days, which can lead to pollination problems, because the insects "do not work so well in those conditions," increasing the risk of the fruit not setting properly.
"The flowering of the Hass lasts for about four weeks, but we have seen that the production volume is determined in the last week of the process, which is when temperatures are most appropriate. This advance in the flowering can cause it to coincide often with rainfall or low temperatures and, therefore, the productivity of the variety is going to be affected," said Hormaza, who explained that researchers are working to try delaying the flowering as much as possible so that it can happen closer to April.
To achieve this, it would be necessary to either use different types of rootstocks, with which researchers at La Mayora are already conducting tests, "or to look for later blooming varieties."
They mention avocado varieties like the Reed, which bears fruit in the summer and blooms a month later than the Hass. He said that the fruit setting "is much better with this variety, possibly because the temperatures at that time are better for the insects and for the plant than when the Hass blooms."
Hormaza said that there are other avocado varieties that are also viable for their cultivation and marketing "and which could be interesting at different times of the year." In fact, he said that La Mayora has a collection of more than 80 different varieties "and, therefore, there is a wide range to diversify ahead of the future."