Posts Tagged: recovery
Avocados Get Hot
If you see significant leaf drop in your groves due to excessive heat, the following actions are recommended:
- As soon as possible, whitewash branches exposed to the sun with special attention paid to branches on the west and south sides of the tree.
- Trees that lose a significant portion of leaves cannot efficiently move water, therefore restrict irrigation amounts to ensure you avoid creating wet, soggy conditions that can lead to root rot. It's best to irrigate less frequently and with smaller amounts of water.
- Do not prune your trees — leave hanging leaves in place to protect the tree from sunburn. Once new tree growth has occurred (in the next 3 – 6 months), pruning can take place on living wood.
- Adjust fertilization as you would with a frost-damaged tree: reducing the amount of fertilizer until the tree is re-established. If you see signs of a particular nutrient deficiency, adjust fertilization accordingly.
For more information about managing heat in avocado groves, growers can view the following articles on the California avocado growers' website:
heat damage gem avop
Fire Resources
Current fire activity in Ventura County reminds us that fire season is here. It's critical to be prepared. Here are some important resources to help you get ready and stay apprised of fire activity in Ventura County.
For the latest fire incident information, visit the Ventura County Fire Department website. This website also contains a wildfire action plan for farmers, ranchers and growers.
We also suggest you bookmark the VC Emergency portal. You can access the Ventura County Emergency Preparedness Guide in English and Spanish.
Here are other resources we recommend:
- Fire in California This is UC ANR's comprehensive fire resources website. This site contains the latest information on fire ecology; wildfire preparation; health and safety in wildfires; wildfire recovery; and more. Useful information for homeowners, land owners and land stewards.
- CA Fire Science Consortium is a network of scientists and managers that strives to increase the awareness, understanding, and adoption of wildland fire science information.
- LUC Lab at UC-Berkeley researching land and land use change.
- ReadyForWildfire.org CalFire's fire resources website, which provides many valuable resources for preparedness.
- **NEW Wildfire Risk to Communities maps by US Forestry Service
Be sure to follow our UCCE Livestock & Range page on Facebook. Advisor Matthew Shapero helms that page and often posts fire information there. If you haven't had an opportunity to meet Matthew, you can learn more about his work in this blog post.
ICYMI, here's a #goodread about Pandemic and Wildfire: California is Preparing for a Crisis Within a Crisis
Stay safe.
Credit: Michael Held, Unsplash
Avocado Orchards After the Fire
The very fact that avocados can be grown in hard to get to places means that the trees are also in areas that are subject to wildfire damage. Recently several hundred acres of avocado burned in the foothills. The fire was fanned by high winds and low humidity.
Every year there are avocado trees that burn, either through careless attention to early morning fires that pickers build, wildfires or car accidents. A grower needs to be patient and observant to bring the trees back into production.
Although injury to foliage and young growth is visible within a few days of the fire, the full extent of the damage may not be known for several months or possibly the next growing season. In the case of severe injury, die-back may continue to occur for several months after the fire. New growth that occurs after the fire may suddenly collapse the following year when the growth is tested by Santa Ana conditions.
The important rule to follow after a fire is to do nothing - don't prune, don't fertilize and maybe don't water. Or rather, water very carefully. Dry winds may have sucked the water out of the ground and may need to be replenished. The fire may have burned the irrigation lines and need to be replaced.
The need to immediately replace irrigation systems will depend on the time of year, the extent of damage, the soil moisture after the fire, the weather forecast, labor availability and many other considerations. It is not terribly expensive to replace hoses, but if PVC sub mains have burned, it will be a big job and it may not be necessary to jump on their replacement. Check the soil and the tree status before rushing to replace an irrigation system. It is on the list of things to do, but maybe not tomorrow.
In the meantime, if the tree has been defoliated by the fire, it has lost its ability to transpire water. Watering a tree with no leaves will set up those conditions that are conducive to root rot. Until the tree begins to leaf out, watch soil moisture to decide how much water the trees are pulling out of the soil. The emitters should be capped or plugged on some leafless trees. Then as the tree puts on new growth, shallow, infrequent irrigations should start. This may mean replacing the 10 gph microsprinkler with a 1 gph dripper if only a portion of the orchard has been burned and the rest of the trees need their usual amounts and frequency of water.
The avocado has a tremendous ability to come back from fire and frost damage. However, the tree will tell you where it is coming back. It will start pushing growth where the tree is still healthy. It may take 3 to 6 months for this growth to occur.
Delay pruning until the tree clearly shows where it is going to regrow. By waiting, you save the expense of having to return sometime later to remove more wood and also will be able to save the maximum about of tree.
An activity the grower can perform is whitewashing. The defoliated tree can be further damaged by sunburn after it has lost its protective cover of leaves. The upper surface of horizontal limbs and the south sides of exposed trunks are the most affected. The whitewash can delay the appearance of new growth, but it does not affect total growth. There is usually no value in applying the whitewash to small limbs.
There are various commercial whitewashes on the market. The easiest to prepare is the cheapest white latex paint on the market mixed with water to the extent that it will go through a sprayer.
Avocado trees have a great ability to recover after fire damage. Even trees killed below the bud union will frequently develop into good trees if they are rebudded and given good care. Trees which do not put out vigorous sprouts should be removed. Interplanting avocados would rarely be advisable because of their rapid recovery.
Fire Information:
http://ceventura.ucanr.edu/Agricultural_Threats/Fire_Information/
For another version of fire recovery, go to: https://www.californiaavocadogrowers.com/cultural-management-library/post-fire-grove-recovery
Photos from Kevin Ball, firefighter/farmer
slow burn through orchard
watching the fire clear weeds
other side of the moon
water on the ashes
Frost Damage in July?
So, this weekend we had some hot weather and the damage from that heat is apparent in all kinds of plants. Sycamores, cottonwoods and willow in the Santa Clara River bottom look torched. Redwoods in the landscape look like a new disease has hit them.
Even old coast live oak in Ojai have been toasted. Orchards have been hit also with been hit without exception. This has been a widespread weather phenomenon like a major freeze. And the trees should be treated as if they have been freeze damaged.
//ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=12275
So, what to do with the avocados and citrus that have been hit? Well, if it's just a slight toasting, nothing. They will grow out of it. It's a setback. The growing points, the terminal buds, have been damaged and in the case of avocados those may not flower next spring. If the damage is not extensive, the whole canopy has not been damaged, then flowering should be sufficient for a good crop next year. If the whole canopy has been hit, it's likely that flowering will be minimal next year.
If the trees have lost significant portions of the canopy, though, the heat damage is not the problem, it's the sunburn damage that is going to happen that is the problem. It's the loss of the leaves that transpire and cool the tree that lead to this kind of damage that can kill small trees and lead to significant branch loss in older trees.
The leaves act like the radiator in a car. They move water through the tree and that water movement carries off the heat that accumulates in the branches and stems. When water flow stops, the bark heats up and tissue is damaged. The worst-case scenario occurs when a “renovated” tree that has been brought down to 6 feet in January and since then there has been new growth all over the tree. The heat fries that new growth and now the whole tree structure is exposed to sunburn damage.
The branches exposed to the sun need to be protected with whitewash. The whitewash needs to be WHITE, not grey. It needs to be able to reflect the sun and prevent the surface from heating. The tops of branches and the west and south sides need to be the most protected, so it often involved hand work. And it needs to be done soon after the canopy loss. That wood heats up fast and damage occurs soon after it heats up.
So what else needs to be done? No canopy, no water loss, so it's necessary to manage the water differently. With no leaves, there is no water moving from soil through the tree, so it just sits there, and the ground stays wet. Perfect conditions for root rot.
Growers who were watering their trees knowing that a heat spell was coming, did the right thing. It probably reduced the severity of the damage, but even growers who had water on before the heat and it was running during the heat have had damage. With canopy damage and loss, applied water needs to be restricted to just enough to get tree recovery without creating a wet, soggy condition. And with tree recovery, it's going to need a continually changing irrigation schedule as new growth occurs.
So now more than ever, water to the tree's growing needs. And the normal fertilizer program needs to be adjusted. There's probably sufficient nutrients in the soil from prior fertilization that nothing new needs to be applied.
And don't' prune the trees. Leave the hanging leaves there. They will help protect the tree from sunburn, but the extent of the damage is not clear. Let the tree push new growth and that will tell you sometime in the future 3-6 months, even a year from this event, when to do significant pruning.
Phlood, Phyre, Phrost, Fytophthora and Phahrenheit continue to plague our industry. It seems like we are always coping with some natural and some unnatural issues affecting agriculture. Oh, yeah and pH.
Photo: Heat singed new avocado growth.
heat damage to new avocado
USDA Fire Loss Programs
USDA's Farm Service Agency (FSA) offers disaster assistance and low-interest loan programs to assist agricultural producers in their recovery efforts following wildfires or other qualifying natural disasters. Available programs and loans include:
- Non-Insured Crop Disaster Assistance Program (NAP)
- - provides financial assistance to producers of non-insurable crops when low yields, loss of inventory, or prevented planting occur due to natural disasters including excessive wind and qualifying drought (includes native grass for grazing). Eligible producers must have purchased NAP coverage for 2017 crops. A notice of loss must be filed within 15 calendar days of when the loss is apparent or 15 calendar days after the normal harvest date.
- Livestock Indemnity Program (LIP)
- - offers payments to eligible producers for livestock death losses in excess of normal mortality due to adverse weather. Eligible losses may include those determined by FSA to have been caused by hurricanes, floods, blizzards, wildfires, tropical storms, tornados lightning, extreme heat, and extreme cold. Producers will be required to provide verifiable documentation of death losses resulting from an eligible adverse weather event and must submit a notice of loss to their local FSA office within 30 calendar days of when the loss of livestock is apparent.
- Tree Assistance Program (TAP)
- – provides assistance to eligible orchardists and nursery tree growers for qualifying tree, shrub and vine losses due to natural disasters including excessive wind and qualifying drought.
- Emergency Assistance for Livestock, Honeybees, and Farm-Raised Fish Program (ELAP)
- - provides emergency relief for losses due to feed or water shortages, disease, adverse weather, or other conditions, which are not adequately addressed by other disaster programs. ELAP covers physically damaged or destroyed livestock feed that was purchased or mechanically harvested forage or feedstuffs intended for use as feed for the producer's eligible livestock. In order to be considered eligible, harvested forage must be baled; forage that is only cut, raked or windrowed is not eligible. ELAP also covers up to 150 lost grazing days in instances when a producer has been forced to remove livestock from a grazing pasture due to wildfire and for beekeepers, ELAP covers beehive losses (the physical structure) in instances where the hive has been destroyed by a natural disaster including flooding, high winds and tornadoes. Producers must submit a notice of loss to their local FSA office within 30 calendar days of when the loss is apparent.
- Emergency Loan Program
- – available to producers with agriculture operations located in a county under a primary or contiguous Presidential or Secretarial disaster designation. These low interest loans help producers recover from production and physical losses.
- Emergency Conservation Program (ECP)
- - provides emergency funding for farmers and ranchers to rehabilitate land severely damaged by natural disasters; includes fence loss.
- HayNet
- - is an Internet-based Hay and Grazing Net Ad Service allowing farmers and ranchers to share ‘Need Hay' ads and ‘Have Hay' ads online. Farmers also can use another feature to post advertisements for grazing land, specifically ads announcing the availability of grazing land or ads requesting a need for land to graze. www.fsa.usda.gov/haynet.
www.fsa.usda.gov/disaster
For more information on these programs, visit FSA online at www.fsa.usda.gov.
To find a local FSA office near you, visit
http://offices.usda.gov.
USDA is an equal opportunity lender, provider and employer.
fire NRCS damage