Pollinating Avocados From Type A to Type B

Reproductive Processes

• Like most other fruit-bearing plants, avocado plants produce fruit from their flower structures. Some plants have male reproductive structures, or stamens, on one flower and female reproductive structures, or stigmas, on another flower. Avocado plants have both male and female structures on every flower. Reproduction occurs when pollen particles from a flower’s stamen get implanted inside a female stigma structure. As flowers naturally secrete fluids that attract insects, such as bees, insects transport pollen particles to stigma structures. Once pollinated, a flower can produce an avocado fruit.

Flower Cycles

• The male and female reproductive structures on an avocado plant appear, or mature, at different times of the day. This process is known as synchronous dichogamy. A single flower opens as a female for two to three hours and then closes. On the next day, the same flower will open as a male, causing the stamen structure to shed pollen. Pollination only can occur when a flower is in the female stage of its cycle, so pollination cannot occur on days when flowers open as males. This means that pollination from one flower type to another must occur during the two- to three-hour period when the female flower appears.

Flower Types

• Avocado plants produce two types of flowers, known as Type A and Type B. Type A and Type B flowers follow different schedules for when male versus female flower structures appear. Type A flowers appear as females in the morning, while the male flower structures don’t become active until afternoon of the next day. Type B flowers have a reverse schedule, with male structures appearing in the morning and female structures in the afternoon of the next day. Pollinating avocado plants from Type A to Type B — also known as cross-pollination — can occur when male and female reproductive structures appear at the same time. Their opposing schedules make cross-pollination more likely than same-flower pollination.

Optimal Conditions

• As avocado plants prefer warm, tropical-like settings, certain temperatures create optimal conditions for pollinating avocado plants from Type A to Type B. Temperatures that average around the 70 degrees Fahrenheit mark during daytime and nighttime hours enable male and female structures to appear at their expected times. Lower temperatures tend to slow the appearance of reproductive structures, making pollination less likely. Since Type B female flowers mature in the afternoon (at the same time as Type A male flowers) planting the two flower types within close proximity also can increase the likelihood of cross-pollination.