By Kyra Fielden – Grower Services Bay of Plenty
FRUITSET AND SOIL MOISTURE
Flowering and fruit set has been looking promising, however natural fruit drop due to a number of factors is still expected and rainfall this year in the Bay of Plenty is approximately 20% lower than last year to date – which could have more impact on fruit drop over the coming weeks.
Providing moisture and nutrients to the trees over the next couple of months through the cell division and fruit growth period is essential for fruit size and quality later in the season.
Soils rich in organic matter (SOM), particularly the ever-stable humus in our soils (that is like a sponge and can hold up to 90% of its weight in water) and with good mulch layers will retain moisture and nutrients more efficiently. These soils continue into dryer periods for longer and recover from dry periods faster than compromised soils, better supporting tree health and crop production.
Good levels of SOM support a strong connection with Mycorrhiza fungi and the avocado tree roots. Mycorrhiza increase the surface area tree roots can reach in soil allowing access nutrients and moisture where roots on their own might not reach.
To hold fruit set through the next several weeks, irrigation will be key in orchards with compromised soil if dry conditions continue.
To further help the soil retain moisture and nutrients, mow pasture sword or inter-rows around trees higher or allow to flower. Longer pasture growing above ground allows roots to grow deeper into the soil building organic matter deeper, feeding biology, improves soil structure, an in some compaction zones can help to loosen soils.
EFFECTS OF WIND
Many orchards in the Bay of Plenty have felt the effects of windfall this season with a number of wind events hitting orchards hard from every angle, often where the orchards have not been affected previously and so have not had the required shelter to protect them. If the fruit has not fallen during these events, it has been severely damaged by wind-rub having a major impact on export packout percentages.
Keeping to an annual pruning strategy will reduce the impacts of wind rub by controlling old branches that may damage fruit, allowing wind to permeate through the tree and keeping trees to a manageable height where they are less impacted by wind events.
Our packhouse staff offer a service where you can watch your fruit being processed, as well as being a rewarding experience after a year of nurturing your fruit, this is also an opportunity to get an understanding of fruit quality issues that hold fruit back from export markets.
During the summer months where pest pressure increases. Keep up your AvoGreen monitoring and remember you can monitor fortnightly if you are tracking population increases and decreases – this is the best way to keep on top them. Please give us a call if you are unsure about what to spray, we can help you with your decision making.
If trees are healthy from the soil up, they are more likely to withstand pest pressure and less likely to attract pests in the first place.
If you have any areas in the orchard that you can leave unmowed and create a wild flower space, this will provide food and habitat for in your orchard for beneficial species like parasitic wasps and predators to
pest species. It’s best if these wild flower areas are within 13 metres flight distance from the tree and are of mixed species and both annuals and perennials to provide nectar and pollen. The Apiaceae (AKA Umbelliferae family) where flowers are like an upside umbrella are important and include wild carrot, fennel, angelica, coriander, parsley, alexander and provide habitat for beneficial insects.
Other flowers to support bees and other species throughout the year are thyme, borage, crimson clover, brassica, phacelia, buckwheat, yarrow and many more. The good people at Kings Seeds can help and have beneficial insect and pollinator blends or you can let existing pasture species to flower, ensure you weed out any unwanted species.