Flowering, pollination, and fruit set is underway in avocado orchards, and this is the most important stage of growing avocados. Fruit set can also present the most challenge for growers but there are many ways they can improve the outcome.The flower to fruit ratio is very low in avocados with a mature tree producing more than one million flowers with fruit set only ranging from 0.3-0.5%.
There are many factors that affect pollination and growers should be on top of those they can control.
Throughout the year, a regular pruning programme will ensure adequate light into the canopy which in turn results in flowers and fruit throughout the canopy. Pruning also results in better bud quality as by pruning you are essentially flower pruning before the tree expends the energy producing the actual flowers.
Avocado orchards are now currently in the peak of flowering and by this stage growers will have worked through their pre flowering checklist.
Pushing spring flush with the appropriate nutrient applications during winter, harvesting some or all of the crop, completing any pruning, correcting nutrient imbalances, and having beehives present from 5-10% flowering are some of the ways to set the orchard up for optimal fruit set before full flowering hits.
Now, the focus is on supporting the tree through very high nutrient demand and withdrawal due to the development of flowers and nectar and in many cases the existing crop is still hanging on the tree as well.
Growers can optimise fertilisation and fruit set by applying foliar fertiliser and flower sprays of specific nutrients.
Boron and zinc are the important nutrients at this time. If you are not regularly applying foliars then ensure you time at least one boron, zinc and seaweed foliar spray when 50% of the trees are at 50% cauliflower stage, 25% at earlier flower development, and 25% approaching full bloom.
Consider also applying foliar spray products that are high in amino acids to support any heavy flowering or stressed trees.
Growers are often conservative with their beehive numbers but depending on orchard density and flowering intensity we recommend having eight to twelve per hectare.
The only way for fruit to set is to have pollen moved onto the flowers, and lots of it. Encourage your bees to stay busy pollinating your flowers by placing a safe source of water close to the hives so they do not have to travel far in search of water.
If, over pollination the weather conditions are not favourable for bee activity, consider applying a pheromone spray.
Bee-Scent™ is a pheromone-based liquid formulation that attracts honeybees to treated blossoms and encourages foraging behaviour.
Soil moisture needs to be managed over fruit set as any water stress can cause higher fruitlet drop.
Should you be fortunate to have irrigation, now is the time that this investment pays off. Use moisture meters to ensure you are applying the required amount of water through dry periods.
If avocado growers need assistance or advice over fruit set they can contact the teams at Avoworks – www.avoworks.co.nz, or Just Avocados – www.justavocados.co.nz.