California Oak Trees Harbor Insect-Eating Bats

Oak Trees in Vineyards a ‘Win-Win’ For Bats and Growers

By Pam Kan-Rice UC ANR Assistant Director, News and Information Outreach

Californians love their oak trees. During vineyard development, Central Coast grape growers often feel compelled to leave an old iconic oak standing, even if it ends up right in the middle of their vineyard. While driving through the Central Coast, it’s not unusual to see the pattern of vineyard rows broken by a majestic oak tree. Aside from their beauty, what are some of the ecosystem services that these majestic trees provide?

To find answers, a UC Cooperative Extension scientist in San Luis Obispo County collaborated with a U.S. Forest Service scientist to study how bats use blue oak and valley oak trees in vineyards. UC Cooperative Extension specialist Bill Tietje, a co-author of the study, says they focused on bats that eat insects because bat populations have declined dramatically in some areas due to habitat loss and disease. “And bats don’t hurt grapes. As a matter of fact, thanks to the huge number of bugs they consume, bats could be very good for a vineyard.”

To understand the potential value of remnant oak trees for insectivorous bats, the researchers placed microphones to detect bat calls within 14 Central Coast vineyards. The recordings revealed 11 species of insectivorous bats foraged within the vineyards. Bat foraging activity was 1.5 times greater at the trees compared to open, tree-less areas within the vineyard. And the bigger the tree, the bigger the number of bats it attracted.

“The study results suggest that the large oak tree in my vineyard not only increases the beauty and biodiversity of the agricultural landscape, but also attracts insect-eating bats that can provide natural pest control—a win-win,” said grape grower Jerry Reaugh, who cooperated with the researchers.

In fact, the trees more than doubled the number of insectivorous bats called woodland-adapted bats within the vineyards. The study indicates that the oak trees attracted woodland-adapted bats that would normally be absent from vineyards.

Tietje hopes that the free insect-reduction services provided by bats will increase grape growers’ incentive to manage and maintain the trees, and even to plant new oak trees in suitable areas around their vineyard, in mutual benefit to both agriculture and biodiversity.

“In addition to their value for insectivorous bats, remnant trees maintain bird and insect diversity by providing food, habitat, cover and stepping stones that facilitate the movement of wildlife within agricultural landscapes,” said Tietje.

This study comes at a time when declining blue oak and valley oak populations are of great concern.

“We hope the study will increase awareness of these beautiful and beneficial trees and make the case for conservation and restoration,” Tietje said. “Preserving and enhancing biodiversity in the midst of climate change is key to ensuring resilience in our landscapes and communities.”

The study by University of Washington graduate student Anne Polyakov, Theodore Weller of USDA Forest Service and Tietje is published in the September 2019 edition of Agriculture, Ecosystems and Environment.

California Ag Today2021-05-12T11:05:02-07:00September 2nd, 2019|

Celebrate Labor Day With California Strawberries!

Add California Strawberries to Your Labor Day Event

By Laurie Greene, Editor

Many people will be out and about with an extra day off on Labor Day, trying to get that last swallow of summer. They’ll crowd beaches, lakes, parks and backyard BBQs. What better way to celebrate the achievements of American workers than to add fresh-picked California strawberries to the menu?

Carolyn O’Donnell, communications director, California Strawberry Commission

“Any holiday can be celebrated with strawberries as they are available year-round,” said Carolyn O’Donnell, communications director of the California Strawberry Commission in Watsonville. “Strawberries are one of the most popular fruits around. They are sweet but low in sugar, and they are quite nutritious. People are often surprised to find out that having just eight medium strawberries gives you more vitamin C than eating an orange,” she said.

“Grown year-round, right now strawberries are coming mostly from the Salinas-Watsonville area on the Central Coast and also in the Santa Maria area,” noted O’Donnell. “As we get more into the fall there will be less coming from the northern sections and more from the Ventura County area to the south. Eventually strawberries will come out of Orange County and Northern San Diego County. The crop will roll back up the coast again with the New Year. By next April or May, strawberries will be coming mostly from the Watsonville area again,” O’Donnell explained.

O’Donnell said that strawberry growers are very dedicated to growing the best possible product they can for their customers. “Their strawberries are actually often a crop of opportunity. A number of our farmers started as field workers and were able to work their way up to owning a farm because you can produce a lot of fruit and make a good living on a small amount of land.”

O’Donnell said supplies should be plentiful in the grocery store. “We probably have more fruit this time of year than usual probably because rain this past winter delayed harvest, which was good news. Now we’re just working our way along. Folks in the Watsonville areas are also beginning to start preparing their other pieces of fallow ground so that they can plant around Thanksgiving and produce next year’s crop,” she said.

Photos: Courtesy of California Strawberry Commission

California Ag Today2016-10-06T16:04:28-07:00September 4th, 2016|

Steve Koike on Resistant Cultivars

The Search for Resistant Cultivars

By Emily McKay Johnson, Associate Editor

In the second part of our series with Steve Koike, plant pathology farm advisor for UC Division of Agriculture and Natural Resources, Cooperative Extension in Monterey County, the focus is on the critically needed research on resistant cultivars. Koike, who has focused his research since 1989 primarily on the understanding of disease systems and the investigation of new methods of disease control, said, “The role or the need for resistant cultivars is tremendous.”

“Some good case studies of resistant cultivar research address soil-born problems on lettuce,” Koike explained. “For example, Fusarium wilt and Verticillium wilt on lettuce could be managed lightly; but in order to overcome those diseases, resistant lettuce varieties need to be in place.”

Steve Koike, UC Cooperative Extension, Monterey County.

“First discovered in 1995 on the Central Coast,” said Koike, “Verticillium wilt has the potential to infect and damage numerous different crops. And although Fusarium wilt was typically unseen in the San Joaquin Valley, it has recently begun to appear on the Central Coast.”

Continued improvement of management techniques upon discovering initial disease symptoms is necessary, according to Koike. “Symptoms of the disease usually appear on the lower leaves of plants, around the edges, and the areas between the veins can turn a yellowish-brown.”

“Strawberries currently have three really important disease pressures state-wide: Verticillium wilt, Macrophomina (charcoal rot) and Fusarium wilt,” Koike commented. “Even the fumigation tools we have are not cleaning them up 100 percent, so we have problems.”

“We will continue to have problems,” Koike elaborated, “until there are truly resistant strawberry varieties to those pathogens. Plant breeders understand that IPM management of these diseases is so dependent on developing resistant varieties,” he said, “but we’re not there yet. We do not yet have truly resistant lettuce or strawberry varieties out in the field,” Koike said.

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Koike and his fellow researchers discovered a new race of the downey mildew pathogen in spinach that has been designated race 16. While there are some varieties that are supposedly resistant to race 16, Koike noted that there is still more research to be done.

To read the first part of our series on Downey Mildew, click here.

California Ag Today2021-05-12T11:05:54-07:00June 27th, 2016|

ILRP Changes Target All Calif. Farmers

Proposed Changes to Irrigated Lands Regulatory Program (ILRP) Could Impact Farmers Statewide

By Patrick Cavanaugh, Deputy Editor

The recently proposed changes to the Irrigated Lands Regulatory Program (ILRP), open for public comment until Wednesday, May 18, could significantly impact farmers, according to Casey Creamer, coordinator for the Kings River Water Quality Coalition. “The proposed modifications concern the east San Joaquin Region, within Madera, Merced and Stanislaus Counties,” Creamer said. “That’s the scope of it.”

According to the State Water Resources Control Board’s (SWRCB) website, ILRP “regulates discharges from irrigated agricultural lands. This is done by issuing waste discharge requirements (WDRs) or conditional waivers of WDRs (Orders) to growers.” Discharges include irrigation runoff, flows from tile drains and storm water runoff, which can transport “pollutants including pesticides, sediment, nutrients, salts (including selenium and boron), pathogens, and heavy metals, from cultivated fields into surface waters. Orders contain conditions requiring water quality monitoring of receiving waters and corrective actions when impairments are found.”

While ILRP currently targets only the east San Joaquin region, Creamer said, “It’s a precedent-setting deal, so everything in there is going to affect not only the entire Central Valley, but the Central Coast and the Imperial Valley—that may not have near the issues or the current regulatory programs that we have here in the Central Valley. So, its very important statewide.”

Creamer emphasized, “Farmers need to know that this is not a minor issue; this is a big issue that affects their livelihoods and their ability to operate. They need to get involved. They need to communicate with their other growers, communicate with their associations, get involved and have their voices heard.”

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The State Water Board is hosting a public workshop on the proposed order on Tuesday, May 17, in Fresno—one day prior to the closing of the ILRP public comment period. The workshop will be held at 9:00 a.m. in the San Joaquin Valley Air Pollution Control District, Central Region, 1990 E. Gettysburg Avenue, Fresno.

The SWRCB is also soliciting written comments on the proposed order. Written comments must be received by 5:00 p.m., Wednesday, May 18, 2016. Please indicate in the subject line, “Comments to A-2239(a)-(c).” Electronic submission of written comments is encouraged. Written comments must be addressed to:

Ms. Jeanine Townsend

Clerk to the Board

State Water Resources Control Board

1001 I Street, 24^th Floor [95814]

P.O. Box 100

Sacramento, CA 95812-0100

(tel) 916-341-5600

(fax) 916-341-5620

(email) commentletters@waterboards.ca.gov

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The Kings River Water Quality Coalition is a non-profit joint powers agency established by the irrigation districts in the Kings River service area. It is governed by a board of directors of landowners from each of the districts. Staffing of the Coalition is administered through an agreement with the Kings River Conservation District located in Fresno. The Coalition was formed in 2009 in order to allow growers within the region a cost-effective avenue to comply with the regulations developed by the Central Valley Regional Water Quality Control Board. The Coalition conducts regional monitoring and reporting and assists members in compliance with regulations. The Coalition is not a regulatory agency. Enforcement of the ILRP is handled by the Regional Water Quality Control Board.

California Ag Today2016-05-31T19:24:04-07:00May 4th, 2016|

Winegrape Grower Earns SIP Certification

Dana Merrill, Winegrape Grower Earns SIP Certification

By Patrick Cavanaugh, Deputy Editor

Dana Merrill is a seventh-generation farmer of an eighth-generation Californian farming family and president of Mesa Vineyard Management, a premium vineyard management service on the Central Coast. A graduate from Cal Poly with an Agriculture Business degree, He is a member of the Merrill Family Estates, an estate that produces premium winegrapes for its Pomar Junction Winery, and he’s extremely involved with the Paso Robles Wine Community.

Recently, his winegrape growing operation earned the Sustainability In Practice (SIP) certification.

“We worked very hard to attain this certification,” Merrill said. “Most of the changes were positive moves. It’s not meant to be a penalizing certification, but there are specific restrictions. For example, we don’t use any Class I restricted materials. If the US Environmental Protection Agency has commented about a substance, ‘Hey, that is Class I. It may be legal, but as an herbicide, it has a tendency to leach into the groundwater,’ then the SIP system won’t allow it. There are times when I’ve said, ‘Boy, I wish I could use a certain material,’ but there are some I simply cannot use in order to qualify for the certification.”

Merrill continues, “The SIP also takes into account how you treat your labor. For example, more ‘points’ are awarded if you offer a benefit program, continuing education support, a retirement program, or health insurance. These days, everybody has to offer health insurance, but points are awarded for that, even though some of us have offered it for over 20 years. Points are also earned for best-practice management whether it is fertility management, soil probes, or having water meters on all your wells and using the information to manage how you irrigate. The idea is to encourage folks to do more and raise the bar.”

“Being SIP-certified helps with marketing too,” noted Merrill. “If you get the SIP seal on a bottle of wine, a consumer can go be assured of the excellent quality of that product.”

“It is marketing in the sense that we are always selling ourselves to the consumer,” Merrill explained. “You know, the consumer may ask, ‘Why should I buy a bottle of SIP wine? Why should I buy California wine?’ I think that branding or labeling conveys a message to customers about what is important to them. Some consumers are very environment-oriented; others are looking primarily for quality. Your label conveys that message. There are customers to whom it is less important, but I see its significance growing. I would say 50% of the people who visit our tasting room find that label on an SIP-certified bottle of wine quite meaningful,” Merrill said.

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Links

Mesa Vineyard Management