Strawberries Need Protection From Mites

New Predatory Species May Help Manage the Pest

 By Patrick Cavanaugh, Editor

Two-spotted mites in strawberries continue to be one of the biggest problems every year.

“We see more of it coming from the nurseries, and this year is no exception,” explained David Peck, COO and Farmer of Manzanita Berry Farms in Santa Maria.

“What’s interesting to me is that in the years that we’ve been using persimilis predator mite, and that has been since the early ’80s, we don’t see the persimilis taking over two-spot populations as early in the season as we used to,” Peck continued. “Whether that’s weather-related, humidity-related, or if there’s a change in the genetics of the commercially available persimilis, I don’t know.”

David Peck

Peck said growers need to be aware of another trouble mite, the Lewis mite.  Lewis mites have been seen on strawberries and raspberries in the Ventura area for some time, but growers appear to be noticing increased infestations in the recent years.  Some growers have also seen them in Santa Maria in recent years, but they have so far not been reported from the Watsonville area.  Considering the recent trend, growers might keep them in mind while scouting for pests.

“They’re out there, some places greater than others. Persimilis don’t like to eat Lewis mite. They are susceptible to all the same miticides. However, if you are relying heavily, on biologicals, you got to know if you have Lewis mite,” Peck said.

“I add fallacis predatory mites early in the season as a preventative for Lewis mite. The fallacis will eat two-spot or Lewis mite equally well and have done a pretty good job of keeping that initial early-season population of both mite species under control,” he explained.

Peck said that if there are mites in the strawberry nurseries, and the nurseries do not want to spray miticides, he understands that due to the possible development of pesticide-resistant mites showing up with plants.

“That’s a valid reason not to spray miticides at the nursery level. But there’s good data that fallacis will exist in those Northern California strawberry nursery areas, and they’re actually less expensive to procure than persimilis, and they survive through a wider environmental range than persimilis. They can handle colder, dryer, and hotter,” Peck said.

Some of the best data on strawberries and raspberries come out of Oregon State. It shows numerical data on how to put out the predatory mites, including how few you can put out.

“Personally, I’d be willing to spend an extra 50 cents or a dollar a thousand if the nurseries would inoculate their fields with fallacis. You might get a few predators coming in with your plants,” he said.

There is additional research on fallacis versus another predatory mite known as andersoni. Data shows that andersoni may be stronger than fallacis, thus doing a better job at controlling two-spotted mites.

Peck said that he has used andersoni on a test basis.

“I did not have enough of the predator to thoroughly complete a test in our organic fields, but I’m thinking that I will use that species for early season mite control.”

Strawberry Labor Issues May be Helped

New Technology in the Strawberry Industry Addresses Labor Issues

By Mikenzi Meyers, Contributing Editor

Once again, technology has taken crop production to the next level. This time, strawberry growers are reaping the benefits of technological advancements. Pete Molero and his team at Plantel Nurseries have come up with a transplanting machine that will address labor challenges in the strawberry field.

“We have come up with a transplanting machine that uses a 25-man crew to plant strawberries that have foliage on them and have a plug just like a transplant vegetable plug now,” Molero explained.

He further added that the machine can plant an acre an hour, a pace that would typically take 80 to 100 employees to achieve.

According to Molero, the process is simple.“The plug goes in, the plant gets dirt, and its set and ready to go.”

He described the root itself as a two-and-a-half to three-inch plug with first growth leaves at about three to four inches tall. As of right now, there is only one variety of strawberry available for the summer. However, new ones are being tested in hopes that this new equipment will continue to make improvements.

Berry Industry Without Methyl Bromide

Berry Industry Must Now Work Smarter in Post Methyl Bromide Era

By Patrick Cavanaugh, Editor

The strawberry fruit production industry, with the exception of plant nurseries, has reached the point where methyl bromide is no longer available under any circumstances, and new alternatives or strategies must be found to protect strawberries from serious diseases.

The University of California is focused on a holistic approach, which includes the tried-and-true method of integrated pest management in this post Methyl Bromide era.

“None of the alternative fumigants are as good as methyl bromide,” said Mark Bolda, UC Cooperative Extension Farm Advisor for Santa Cruz County, who is working closely with growers on alternative methods. “So one area that we could focus on is different strategies at the time of planting. For example, strawberries have different chill times. You must add cold conditioning to give the plant more vigor.”

Mark Bolda

There are many questions. Could the colors of the plastic mulch that growers are using manage the temperatures of the soil? How about the amount of fertilizer that is being used?

“We need to start integrating these variables into the way we grow strawberries with the lack of fumigants that are as effective as methyl bromide,” Bolda explained. “We need to integrate all these things and others in order to grow berries with the lack of available fumigants that are as effective as methyl bromide.”

“It’s a little disappointing that here we are at zero-hour and we do not have this worked out,” he continued. “The University of California Cooperative Extension have had a number of meetings in my office, as well as other places where we get many people in the same room to try to figure out what we know and what we don’t know.”

“There’s a lot of smart people in the industry, and I know we can get on this and find solutions,” he said.

Strawberry Commission Oversees Valuable Crop

Strawberries in California

By Jessica Theisman, Associate Editor

Strawberries are California’s sixth most valuable crop which makes strawberry research a valuable tool for California farmers.  Mercy Olmsted is senior manager of production research and education at the California Strawberry Commission. Growers in the California Strawberry Commission have invested over $28 million into research. These include areas such as diseases, insects, and weeds—all in an effort to help solve production challenges and boost economic gains.

“We are a commission that’s funded by the growers, and so we do research that meets their research priorities,” Olmsted said.

So far, $13 million has been invested in research to explore alternatives to methyl bromide. The commission says that strawberry farmers continue to invest in researching fumigant alternatives.

“We also work with researchers. We have a robust grant program, and we work with those researchers in order to assist them in their field trials,” Olmsted explained.

Some of their researchers are in house, and others are from the USDA and university researchers.

“We develop training programs for our growers because we work for the growers. We can contact them as often as we need to, and we are able to see how things and research priorities might change in the industry,” Olmsted said. “There are a number of facilities and a board that helps direct research priorities and any necessary changes.”

For more information on strawberry research being done by the California Strawberry Commission visit calstrawberry.com.

Aza-Direct Stops Insect Feeding

Aza-Direct Targets Critical Pests

By Patrick Cavanaugh, Editor

Aza-Direct, with the active ingredient Azadirachtin, is one of the most potent, reduced risk insect pest controls among all the natural pesticides.

With four modes of action, Aza-Direct targets critical pests such as spider mites, thrips, whitefly, aphids, and lygus. It’s very safe with beneficial insects, especially bees, to help maintain the natural balance within the crop.

The product has a lot of excellent benefits regarding those four modes of action, explained Patrick Holverson, Director of Ag Business with Parry America Inc., which manufactures the active ingredients for Aza-Direct.

“Because of the four modes of action, you will not get a resistance buildup like you can with standard chemicals,” Holverson said. “What I like about it, many growers in California will apply Aza-Direct in anticipation before the target pest hits because it is not a contact killer; it takes two or three days to get into the pest’s system to reduce the population.”

Furthermore, the material is an excellent repellent and as well as an anti-feeding agent.

“Those pests who stay in the treated field will experience severe feeding cessation due to a locked jaw and digestive system,” Holverson said. “So, the pests that do feed on the plant, the material acts as an insect growth regulator that affects both the eggs and the larva, preventing them from reaching maturity.”

Holverson said that in strawberries, Aza-Direct controls two significant pests—including two-spotted spider mite and lygus—that come in after losing their host crop.

“The product prevents puckered strawberries and increases the value of the crop,” he said. “It can be used on both organic and conventional crops.”

It has a zero-day pre-harvest interval, and four-hour re-entry, which is essential in a crop such as strawberries.

Researchers Take a Look into the Future of Strawberries

Survey Coming to Growers to Gauge Interests

By Hannah Young, Associate Editor

A strawberries survey connected to a project that looks at the future of strawberry genetics will soon be sent to strawberry growers.

Daniel Tregeagle, a postdoctoral scholar of agricultural economics at UC Davis, is working on the survey.

“This project is being run over the state of California, through a number of different institutions, different universities, including the state of Florida,” Tregeagle said. “Strawberry growers all over the country are trying to find out what we should be breeding in the next generation of strawberry cultivars.”Strawberries

The project is part of a Specialty Crop Research Initiative, which is considering what growers are looking for in the next generation of strawberries, Tregeagle said.

“Do they want better yields? Do they want more attractive features that the consumers are going to like? Do they need disease resistance?” Tregeagle asked.

However, growers can’t have everything, because when a cultivar is strong in one area, they tend to be less strong in other areas.

“So what we’re doing in the survey is asking growers what are the main diseases that they’re facing, how are they managing those diseases currently and what would they do differently if they had a better, more resistant strawberry cultivar that could resist those particular diseases,” Tregeagle explained.

Researchers are also interested in looking at fumigation and how they might change in the presence of a more resistance cultivar, Tregeagle added.

Conventional or Organic Strawberries — All Safe to Eat

Strawberry Grower Says At PPB, Anything Can be Found

By Patrick Cavanaugh, Editor

David Peck is a longtime strawberry grower in Santa Maria. He objects to the Environmental Working Group’s (EWG) Dirty Dozen list, which had strawberries at the top of their list.

David Peck, COO and Farmer of Manzanita Berry Farms in Santa Maria

“If you take the data that the EWG is presenting, you can say, yeah, okay, that’s fair,” Peck said.

“Based on what they are presenting, they can find detectable amounts of whatever at however many parts per billion. I’ll buy that; but they’d have no perspective on the types of residues and what that means regarding human health, human safety, and human risk,” noted Peck, who grows both conventional and organic strawberries.

Peck said that even organic strawberries would have detectable amounts of residues.

“I tell people that I grow organic strawberries and that I do not put on the crop protection materials that the EWG is talking about,” he explained.

“At parts per billion (PPB), you can find dozens of carcinogens at minute levels. Where did they come from? Well, they are everywhere in such small quantities that no one should worry about it,” Peck said.

Peck said that the decision for consumers is not organic versus conventional, but to eat more strawberries and other fruits and vegetables.

“I say eating California produce in general is so much healthier than avoiding California fresh fruits and vegetables,” he said.

The Alliance for Food and Farming works hard to bring the truth to the EWG’s Dirty Dozen list. They report that all produce is healthy to eat and that consumers need to eat more every day. More Information at www.safefruitsandveggies.com

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
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.

generational_small strawberries

 

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