Yield is the key driver for profitability when growing avocados, and good yields are a result of successful floral initiation, floral development, pollination, and fruit set. Disturbances with any of these processes will have a negative effect on fruit production, which cannot be alleviated by alternative management practices. It is therefore important to understand the factors at play in the reproductive processes in avocados to optimise your yield.
1. Climate matters
Temperature during flowering affects everything from the timing of male and female phases to the success of fertilisation.
- Sweet spot for B-types (e.g. Fuerte): 25 °C days and 20 °C nights. At this range, male and female phases overlap and pollen is available to receptive stigmas.
- A-types (e.g. Hass): Less sensitive to cooler temperatures but still vulnerable. Fruit set can occur at 17 °C days and 12 °C nights, though pollen availability drops sharply.
- Why stability counts: Pollen tube growth starts within 3 hours at optimal temperatures, but full fertilisation can take up to 48 hours. A sudden cold snap midway through this process can result in reduced fruit set or “cukes” (seedless fruit).
2. Nutrition boosts fertilisation
Boron and nitrogen foliar sprays at the “cauliflower” stage of inflorescence can:
- Increase the number of pollen tubes reaching the ovule
- Improve ovule viability
3. Pollinators make the difference
Avocado flowers can be visited by many insects, but in South Africa and most avocado regions, honeybees are the most important. In Mediterranean climates like the Western Cape, their presence directly correlates with fruit set.
Key facts:
- Only 20–30% of bees collect pollen; most forage for nectar. Nectar collectors are far more effective for pollination.
- Bee activity peaks mid-morning and declines by afternoon.
- Best practice: 3–5 hives per hectare or groups of 6–10 hives every 400 m for maximum coverage.
4. Shade nets friend or foe
Shade nets improve microclimates and fruit quality but they complicate pollination. Nets reduce insect movement and can deter bees unless managed properly.
Research suggests:
- Nets should be at least 8 m high, leaving 1–1.5 m between canopy tops and the net for free bee movement.
- Water must be available inside the nets (simple drip lines near hives work).
- Place hives at edges only if bees have no competing nectar source within 3 km. If nearby citrus is flowering, bees will switch camps.
- Rigid pruning keeps trees open and sunlit because bees dislike dense, enclosed spaces.
5. Keeping bees interested in avocado flowers
Avocado blooms are pale and low in nectar which is not exactly bee friendly. To maintain bee activity:
- Manage tree height and width so bees move freely between trees.
- Avoid bio-sugars or “bee baits” because bees learn to ignore these scents.
- Check hive strength: at least 60 bees per minute leaving the hive indicates a strong colony.
- Do not spray insecticides during flowering.
- Plant nearby bee-friendly flowers (African basil, etc.) to keep colonies close.
6. The power of cross-pollination
Cross-pollinating varieties often outperform self-pollination:
- Only about a third of Hass pollen tubes reach Hass ovaries.
- Half of Ettinger pollen tubes do which makes it a strong cross-pollinator.
- In South Africa and Israel, Ettinger has successfully boosted Hass yields.
Before interplanting:
- Select the right cross-pollinator for your main cultivar.
- Confirm flowering overlaps.
- Plan polliniser density.
- Have a plan for handling polliniser fruit at harvest.
7. The bottom line
Avocado pollination is a delicate, time-sensitive process. To maximise fruit set:
- Support trees with boron and nitrogen at the right stage.
- Provide 3–5 strong beehives per hectare and manage shade nets for bee movement.
- Keep bees engaged with thoughtful orchard layout and companion planting.
- Use cross-pollinators strategically to improve yields.
Healthy trees, active pollinators and the right cultivars working together mean more fruit on your trees and stronger returns from your orchard.
For the full article with illustrations, pictures and more in-depth information, click here to read ROOTED e-mag Issue 3.