Pre- and Post-Harvest Irrigation Management in Prune
Read this article to learn more about irrigation management for prune orchards using crop developmental stages and stem water potential measurements. Continue reading
Author Archives: Luke Milliron
November 2020, Another Major Autumn Freeze in California Walnuts
As if 2020 didn’t bring enough grief, it appears to have also brought a major autumn freeze that growers and their consultants are now taking stock of. UCCE walnut advisors in the northern Sacramento Valley and Northern San Joaquin Valley have been fielding calls in the past couple weeks regarding extensive damage in young and mature orchards. Continue reading
April Almond Orchard Management Considerations
Read this article for almond orchard management tasks to keep in mind in April. Continue reading
Emergency Use (Section 18) Approved for Almond Bacterial Blast Material
Bacterial blast (Pseudomonas syringe), although thankfully not a problem every year (hopefully including 2021), can be tremendously damaging to almond yields. For example, significant crop damage was reported in the Sacramento Valley in 2017 and 2018, and in the San Joaquin Valley in 2017 and 2019. These grower reports of past crop loss supported a Section 18 emergency request for the use of kasugamycin on almonds during bloom. Continue reading
Almond Leaf Scorch
Beginning in late June, several PCAs and growers reported trees in almond orchards in the Sacramento Valley with symptoms like those of almond leaf scorch (ALS), a disease caused by the bacterium Xylella fastidiosa. UC farm advisors and UC and USDA plant pathologists have begun a survey to confirm disease presence and improve understanding of the disease in the Sacramento Valley. Continue reading
Fall & Winter Prune Orchard Management Considerations
Fall and winter orchard management considerations range from irrigation and plant nutrition to weed, pest and disease management. Continue reading
Fall- Preparing for Extreme Events: Freeze and Fire
The sudden November 2018 freeze event that caused extensive damage in many walnut orchards is a stark reminder that we must do our best to prepare against extreme events. Continue reading
Tree and Orchard Replanting Considerations in a Lean Price Year
When prices are lean walnut farming is tough business. Farm advisors are not economists or financial advisors. However, farm advisors can be useful in providing best practices for economically sustainable production. Two key economic decisions growers face are when to replant individual trees and when to remove and replant entire orchards. Continue reading
Variable Bloom Weather Leads to Variable 2020 Prune Crop
The 2020 prune bloom and crop set monitoring carried out by UCCE farm advisors showed dramatic differences in the prune set between different prune production regions. Some orchards require thinning this year, while some will achieve great fruit size without thinning. Continue reading
Update on Rootstocks for Prune Production – 2019
Two rootstock experiments in grower orchards were planted in Northern California in 2011. One site in Butte County and a second in Yuba County. The two sites are evaluating the performance of Improved French on 14 rootstocks planted in replicated randomized trials. We previously reported in this newsletter on the results from this trial in 2015 and 2017 issues. Here, updated results are given. Continue reading
Monterey and the Leafing Failure: What could be causing it?
Researchers have historically been unable to pin down a cause for leafing failure because it was a rare event, only being reported periodically in the last couple decades. The problem was noted periodically before 2000, but most recent reports were made by farm advisors of leafing failure symptoms in 2000, 2006, 2010, 2017, 2018, and 2020. Continue reading
Monterey and the Leafing Failure 2020: What are we seeing?
In 2018 Dani Lightle reported leafing failures in Monterey following several calls she investigated. In 2020, UC advisors, specialists, and professors are again receiving calls reporting leaf out issues in several almond varieties, but most notably in Monterey. Continue reading
Irrigation with Roots in Mind
A key role of roots is the uptake of water and nutrients. Roots do not function well when exposed to too much water and will stop growing and eventually die in stagnant and/or saturated soil conditions. We consider how a better understanding of root biology can inform best irrigation practices. Continue reading
Autumn 2018 Freeze Event a Year Later
An autumn freeze event in November 2018 caused widespread dieback in both young and mature walnut orchards in the Sacramento and northern San Joaquin Valleys. Following our initial diagnosis in April 2019 and our update on regrowth at the end of May 2019, we revisited several affected orchards at the end of the 2019 season, nearly a year after the freeze event. Continue reading
Emergency Registration Approved for Almond Bacterial Blast Material
Bacterial blast, although thankfully not a problem every year (hopefully including 2020), can be tremendously damaging to almond yields. Because Sacramento Valley almond growers were significantly impacted by bacterial blast in two of the last three years, crop loss data from Sacramento Valley counties supported a Section 18 emergency request for the use of Kasugamycin on almonds. Continue reading