- Author: Marcelo Moretti
- Posted by: Gale Perez
Oregon leads the United States in the production of Christmas trees, with almost 8.5 million trees sold in 2015. Weed control is essential in Christmas trees to reduce competition for moisture and nutrients, allow fast and robust tree growth, and ensure growers top prices for high-quality trees. Research is needed on weed management in Christmas trees in the West to ensure they remain economically competitive. Herbicides are the primary weed control option for Christmas tree growers, but options are limited, and herbicide-resistant weeds challenge weed control. Herbicide resistance has increased weed management costs in Christmas trees; growers must now turn to mixtures of herbicides or planned rotations. Increased diversity of herbicide modes of action is needed to manage herbicide-resistant weeds and to maintain the competitiveness of Oregon Christmas tree production.
Four field studies were initiated between January and February of 2022 in commercial Christmas tree farms in the Willamette Valley. The trees were Douglas fir and Nordman fir in the second year after transplanting. A single application was made over the top of the young trees mimicking growers' practices with other herbicides.
Initial Results
The study is ongoing, but I will share some data from 12 weeks after the treatment. To date, no crop injury has been observed in any of the studies in Douglas Fir or Nordman fir treated with Fluridone at the expected field rate and twice that, equivalent to a Brake On! rates 43 and 83 fl oz/A. These encouraging results include growth measurements unaffected to date by these treatments. Growth measurement data are not shown.
Most of the research sites had low weed pressure, making it difficult to assess weed control. Postemergence herbicides were not included in the treatments. One of the fields planted with Nordman firs was infested with false dandelion (Hypochaeris radicata) and rattail fescue (Vulpia myuros). Most of the treatments did not provide good control of false dandelion that was present at the time of the application. Fluridone did not control false dandelion (<28%) regardless of the rate but did control rattail fescue (58–85%) (Table 1). When Brake on was used in mixtures, the mixture of simazine + Goal Tender + Brake On resulted in 73% control of false dandelion and 91% control of rattail fescue. Cleantraxx controlled 86% of false dandelion and 92% of rattail fescue.
Mixing fluridone with other preemergence herbicides will expand the spectrum of weeds controlled in Christmas tree plantations. Simazine and Goal Tender were included in this study as the grower standard treatment. Fluridone improved weed control compared to that mixture. The results are becoming more apparent as the season progresses (Figure 2), and we will continue assessments during the 2023 season.
Fluridone is currently not registered in Christmas tree, but the initial results are promising and will be used to support a future registration of Brake On! in Christmas tree.
Acknowledgments
I would like to thank the many Christmas tree growers that hosted studies, and the support from the Christmas Tree Promotion Board.
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Marcelo Moretti is a Weed Science Assistant Professor in the Department of Horticulture at Oregon State University. He is also an alum of the Hanson Lab at UC Davis.
Original source : Weeders of the West blog
- Author: Lynn Wunderlich
Mike McGee grows Christmas trees in El Dorado county and has been using stump culture on his 19 acre Choose n' Cut Farm for 36 years. According to Mike, stump culture reduces the time to harvest for a White Fir from 8-10 years to 5-7 years. One stump can provide as many as eight harvested trees.
For those of you who think growing Christmas trees is as easy as planting a few conifers and forgetting about them, beware. Christmas tree production and stump culture takes work to produce a good looking tree. The cut, number of nurse branches, and selection of final tree sprout all affect the resulting success and tree quality. McGee goes back to each harvested stump in January and recuts the stump using a sharp saw to produce a clean cut. He then paints the stump using a 4 inch roller and an elastomeric coating, which is dense and will stretch. The coating helps to prevent the stump from rotting until the tree's nature sap overgrows it, sealing the stump.
The bigger the tree stump, the more nurse branches that are left. Typically this means leaving 10-12 branches around a white fir. New trees will grow up from either a nurse branch limb that turns up-not desirable due to the bend in the bottom- or a new sprout which will grow straighter, and is therefore more desirable than a tree grown from a turned up limb. The limbs fold up and shade the cut stump, nature's way of protecting the cuts that heal better when they have shade.
- Author: Jeannette Warnertte
Reposted from UCANR News
Most California forests have too many trees, so carefully selecting pines, cedars or firs in natural areas to enjoy for the Christmas season is good for the mountain landscape.
“It's a great idea to cut down young trees for fire safety and vegetation management,” said Susie Kocher, UC Cooperative Extension forestry advisor in the Central Sierra. “The earlier you do it, the less work it is to manage the trees in the long run.”
Kocher lives and works in Lake Tahoe. Every year, she gathers her family and friends to find forest-fresh Christmas trees in the Lake Tahoe Management Area. Of the 18 national forests in California, 11 allow Christmas tree cutting with the purchase of a $10 permit. (See the list below.) People who own mountain cabins or other forestland may invite family and friends to help thin trees on their personal property, which can then be used for the holiday season. However, never harvest trees on public or private property without permission.
“We have a lot of small trees on public and private forest lands because of fire suppression,” Kocher said. “They're all competing with one another and many will ultimately die. A smart harvest of Christmas trees can improve the forest by helping with thinning.”
People with permits to cut down Christmas trees in national forests must follow strict guidelines. Follow the same guidelines on private land to ensure a smart harvest. Before chopping down the tree, be sure it is within 10 feet of another living tree, the trunk is no more than 6 inches in diameter and the stump left behind is no higher than 6 inches off the ground. Some national forests limit the harvest to certain tree species.
Despite committing to these guidelines when obtaining a permit, Kocher said she has seen some Christmas tree harvesters make ill-advised choices.
“Some people are too lazy to find a good tree and will cut the top off a large tree,” Kocher said. “You can be driving around and see what looks like a poor old Dr. Suess tree, which is what grows from the ugly remnant left behind in the forest.”
Such irresponsible Christmas tree cutting has led some forests to discontinue Christmas tree harvesting for personal use.
There has been ongoing debate about whether a fake tree or real tree is more environmentally friendly, but for Kocher, there is no question.
“Fresh real trees are a renewable resource, fake trees are not,” she said. “It's an agricultural product. You can contribute to a local farmers' income or you can help thin the forest. Picking and bringing home a fresh tree, decorating it and smelling it defines the season for me. Without it, I don't think it would feel like Christmas.”
U.S. National Forests in California that allow Christmas tree cutting with a permit are:
- Inyo National Forest
- Eldorado National Forest
- Klamath National Forest
- Lake Tahoe Basin Management Area
- Lassen National Forest
- Mendocino National Forest
- Modoc National Forest
- Plumas National Forest
- Shasta-Trinity National Forest
- Six Rivers National Forest
- Tahoe National Forest
Read more:
- Author: Pam Kan-Rice
- Posted by: Susie Kocher
If you have a real Christmas tree, University of California pest management experts ask that you to recycle the tree to prevent the spread of insects and diseases that may harm our forests and landscape trees.
“Invasive insects, diseases and plant seeds can move on cut Christmas trees and other holiday greenery,” said Janice Alexander, UC Cooperative Extension forest health educator in Marin County. “These pests can escape out into backyards and neighboring forests to begin new populations, upsetting the balance of our native ecosystems. Proper purchasing and disposal of holiday greenery helps reduce that risk.”
Alexander recommends taking advantage of local tree recycling programs.
“Many municipalities and service organizations offer this service right at your curb,” she said. “If you aren't able to find or use this option, take the tree to your local solid waste facility, dump or landfill. This will keep any pests that might be in the tree from spreading and the landfill uses the material as cover.”
“You should not try to burn the wood indoors as fresh sap can create fire hazards,” she added, “and don't set the tree out in a backyard brush pile where pests and weed seeds could escape onto your property.”
“The most worrisome pests that might be traveling on Christmas trees or greenery this year include P. ramorum, pine shoot beetle and gypsy moth,” Alexander said.
The movement of some fresh trees is regulated. For example, Douglas fir trees are regulated because they are hosts for Phytophthora ramorum, which causes sudden oak death. The disease has killed millions of tanoak trees and several oak tree species in forests throughout California since the mid-1990s.
Pine shoot beetle and gypsy moth are not currently in California, but they could damage the state's Christmas tree plantations and forests if they were to become established.
Pine shoot beetles, Tomicus piniperda, feed on shoots, stunting the growth of pine trees. Large populations of the insects can kill apparently healthy trees.
Gypsy moth, Lymantria dispar, attacks forests and landscape trees, including manzanita, western hemlock, Douglas fir and live oak. Gypsy moth caterpillars feed on hundreds of plant species and are capable of defoliating trees at an alarming rate. A single gypsy moth caterpillar can eat up to one square foot of leaves per day, according to the California Department of Food and Agriculture.
“According to the Don't Move Firewood website, Christmas trees are generally deemed safer than firewood in terms of invasive pests,” Alexander said. “However, safe disposal of trees is still important.”
For more information about sudden oak death and forest health, visit Alexander's website athttp://cemarin.ucanr.edu/Programs/Custom_Program816. More information about holiday greenery pests can be found at theUSDA APHIS website and the Don't Move Firewood websitehttp://www.dontmovefirewood.org/HolidayGreenery.
- Author: Jeanette Warnert
- Posted by: Susie Kocher
Reprinted from the UCANR Green Blog
Every year, the day after Thanksgiving, Susie Kocher bundles up her children, gathers the extended family and hikes into the Lake Tahoe Basin forest to find a Christmas tree.
“It’s my favorite part of the season,” Kocher said. “Having the fresh, living thing in the house really symbolizes the holiday. You can’t do it with a fake tree.”
Kocher, a forester and the natural resources advisor for UC Cooperative Extension in the Central Sierra, lives and works in Lake Tahoe. The Lake Tahoe Basin Management District is one of nine national forests in California, all of them in the northern part of the state, where the U.S. Forest Service allows Christmas tree cutting with a $10 permit.
Though some people mourn the death of any tree, Kocher says careful selection and removal of Christmas trees is an enchanting family tradition that enriches forest health.
“We have a lot of small trees on public lands because of fire suppression,” Kocher said. “They’re all competing with one another and many will ultimately die. A smart harvest of Christmas trees can improve the forest by helping with thinning.”
People with permits to cut down Christmas trees in national forests must follow strict guidelines. The trees must be within 10 feet of another living tree, the base of the trunk cannot be more than six inches wide and it must be cut within six inches of the ground. Some national forests limit the harvest to certain tree species.
Despite committing to these guidelines when obtaining a permit, Kocher said she has seen some Christmas tree harvesters make ill-advised choices.
“Some are too lazy to find a good tree and will cut the top off a large tree,” Kocher said. “You can be driving around and see what looks like a poor old Dr. Suess tree, which is what grows from the ugly remnant left behind in the forest.”
Such irresponsible Christmas tree cutting has led some forests to discontinue Christmas tree harvesting for personal use.
Kelly Hooten, information specialist with the Sierra National Forest, said the organization stopped issuing Christmas tree cutting permits because people would tend to cut down only healthy, strong trees.
“It’s really the sickly, Charlie Brown trees that we would prefer to thin in our forest,” Hooten said.
The El Dorado National Forest does not allow Christmas tree cutting because there are more than 30 Christmas tree farms in the vicinity where visitors can choose and cut down their own trees.
“Allowing Christmas tree cutting in forests would hurt these farmers economically,” said Lynn Wunderlich, UCCE advisor in the Central Sierra office. Many Christmas tree farmers also provide food, crafts, activities and visits with Santa.
“Families can visit the farmer year after year as their children grow, so that’s part of the experience,” Wunderlich said.
There has been ongoing debate about whether a fake tree or real tree is more environmentally friendly, but for Kocher, there is no question.
“Fresh real trees are a renewable resource, fake trees are not,” she said. “It’s an agricultural product. You can contribute to a local farmers’ income or you can help thin the forest. Picking and bringing home a fresh tree, decorating it and smelling it defines the season for me. Without it, I don’t think it would feel like Christmas.”