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Avocado News

Late Summer Cultural Report

By July 22, 2019October 21st, 2022No Comments

Heading into late summer 2019, West Pak Field Managers Andy Gabryszak and Mike Harberson assess what California growers should look out for in the warmer months of August and September.

Pest Control & Monitoring

According to Andy, perseae mites should continue to be monitored, especially if the mild California weather continues. Brown mites, while not a significant pest, can cause defoliation if left unchecked. It’s advised to monitor for the mites and treat accordingly with a 415 oil or a miticide as desired.

The good news pest-wise is that the earlier omnivorous looper problem seemed to take care of itself after the June heatwave. The hot spell also knocked out the light numbers of avocado thrips. At this point, all fruit has sized large enough so that there is little to no danger of scarring from the thrips.

Fertilization & General Care

Following the growers’ most recent leaf/soil analysis, Andy expresses that fall fertilizer programs should be in the planning stages. Most ranches are currently running some type of nitrogen, an essential nutrient to feed the new flush.

According to Mike, growers should also asses avocado tree crop loads and summer flush to determine whether these factors will place their trees into an alternate bearing cycle. In addition and if necessary, he advises thinning a heavy crop with a light pruning that does not lead to a frost-sensitive autumn growth flush.

Coming up as soon as mid-September Andy says that growers should be ready for any needed girdling as well as phos acid applications. Girdling, which is the act of cutting through the cambium around a branch, is designed to help keep the nutrients in the branch to allow it to become more fruitful. Phosphoric acid (aka phos acid) acts as a fertilizer and works as a stimulant that can help trees offset the effects Phytophthora cinnamomi or root rot.


This time of the year, Mike suggests flushing accumulated summer salts from grove soil with leaching irrigations before the winter rains. Leaching, in this case, refers to the practice of applying a small amount of excess irrigation where the water has a high salt content to avoid salts from building up in the soil.

To stay ahead of hot weather or wind events, Andy strongly urges growers to watch the 10-day weather forecast mindfully. To help in the process, he suggests signing up for West Pak’s weather email (see Maria or Margie). He also recommends checking irrigation lines regularly to assure that they are running clear and there are no breaks or leaks. This assessment also ensures that growers are as efficient as possible with our most valuable resource – water.

In closing, both Andy and Mike invite farmers to reach out to their West Pak field representative should they have any questions or concerns on any issue. The West Pak field team is ready and willing to help in any way that they can.