By Erica Faber – Technical Manager
Most Just Avocados growers completed their first pick by December 2020, and many have now fully completed their harvest. This is important for consistent year-on-year cropping as the resources can be primarily directed to the currently setting and developing 2021-22 crop without the added strain of late hanging fruit.
Fruit set is a stressful time for avocado trees due to the high demand and competition for resources between the current crop, the setting fruit, the spring vegetative flush and the root flush.
An avocado tree only has so many resources to go around and when holding a significant amount of crop late, the new fruit set or spring flush is often compromised. Inadequate carbohydrate reserves or nutrient resources to the fruitlets results in either poorer fruit set or higher fruitlet drop.
If left unchecked, a cycle can perpetuate where resources get exhausted one year and then build up again the next in an “off year” only to overflower again the next year. This is primarily the cause of irregular bearing.
The challenge is to balance the resource needs of all these growth cycles to ensure optimal tree health and consistent high yields.
Managing the basics can help to achieve this:
- Ensure adequate and balanced nutrition with a combination of solid and foliar fertilisers. However, avoid excessive Nitrogen fertiliser during fruit set as this can result in an increase in fruitlet drop.
- Any water stress over fruit set results in higher fruitlet drop and consequently lower production. Although our rainfall is high, we unfortunately often have dry periods over the critical time of fruit set. A water deficit during this critical time of rapid cell division will also result in smaller fruit. Irrigation is a worthwhile investment to ensure not only larger fruit but also larger crops.
- A regular pruning programme will ensure adequate light into the canopy which in turn results in improved production with a more even crop load on the entire tree and not just predominantly the top or the periphery. It also results in better bud quality and higher fruit set as well as a balance between vegetative and productive wood, which in turn will prevent excessive or over flowering.
- Manage your crop load and carefully consider your harvest strategy. A heavy or late hanging crop will compromise next season’s production as well as decline poor health trees even further.
If you need to get crop off now or would like assistance with your orchard management programme, please talk to the Just Avocados Frower Services Team or Avoworks www.avoworks.co.nz.