Tomato Spotted Wilt Virus Fights Back

New Strain Creates Challenges

By Mikenzi Meyers, Associate Editor

A new strain of the Tomato Spotted Wilt Virus has created a challenge among vegetable growers, making integrated pest management, or IPM, increasingly critical. Bob Gilbertson, plant pathologist at UC Davis, has insight and advice as to how farmers should tackle this new strain.

“The first thing is to know what’s out in your field. And there’s a good diagnostic test for curly top, spotted wilt, alfalfa mosaic, and other viruses,” Gilbertson said.

Bob Gilbertson

After the virus is confirmed, he encourages growers to explore their options of treatment. Prior to the new spotted wilt virus strain, growers could turn to the SW-5 resistance gene to cure their field. Unfortunately, Gilbertson explained, the new strain actually breaks that resistance, which is where IPM becomes even more important.

In the future, Gilbertson hopes to find additional resistance genes to break the new strain. Until that time comes, he wants to use good IPM to manage it.

Gilbertson further added, “Increased sanitation, removing overwintering hosts, weeds, and bridge crops like lettuce, and then timing the applications of thrips management better, to slow down the appearance of adult thrips that carry the virus,” are all examples of good IPM.

Bowles Farming Co. Shares Success Secrets

Google Hangouts Helps Bowles Farming Communicate Throughout 

By Mikenzi Meyers, Associate Editor

When it comes to agriculture, Merced County-based Bowles Farming Company has it figured out. With 160 years of experience, and six generations worth of history, the company has had a major influence on the state. Danny Royer, Vice President of Technology at Bowles, has valuable insight on what makes the company so successful.

Royer is in charge of the technology behind growing various crops including tomatoes, cotton, wheat, watermelon, and other organic commodities. He said that the key to solving issues is by sharing data within the operation.

“Data is what’s going to provide the solution, but we have to create systems that give the people [the data] who have the competencies to solve the problem,” he explained.

One way Bowles Farming Co. is able to achieve this is by using Google Hangouts on the farm, which enables them to communicate with different sectors of the operation single-handedly.

“We’ve got to be a little more transparent and open about sharing our information with people that are coming from the tech sector trying to help us,” Royer said.

Spotted Wilt Virus Light This Season on Tomatoes

Thrips Widespread But Yields are High

By Patrick Cavanaugh, Editor

Spotted wilt virus on tomatoes was a big concern at the beginning of the season. California Ag Today spoke with Tom Turini, vegetable crops farm advisor for the University of California Cooperative Extension in Fresno County, about the topic. We caught up with him on the west side of Fresno County. He said despite the potential virus pressure, tomato yields have been very high this year.

“Thrips are the vector of tomato spotted wilt, and while the thrip distribution is much wider than it was last year, it doesn’t look like we’re seeing the level of economic damage,” Turini said.

Tom Turini

“We had had concerns initially about problems, and of course that could get worse as we get later in the season, but so far our yields have been very, very high,” Turini said.

He explained that the strong yields is in part due to the mild temperatures during the spring, so there was good early fruit set. “Even that, I would expect that now with these higher temperatures over the last six weeks, we’re going to start seeing the effects of the yield-robbing virus with a later harvest, he said.

Last year, the concern was with fresh market tomatoes.

“We had concerns late last year in the fresh market, but this year it’s at moderate levels of economic impact. “It doesn’t mean it couldn’t happen in the future, but at this point, it looks like we were spared, at least for the early season crop.

Caltec Shares Innovative Pest Control Practices

A New Approach to Managing Vine Mealybug

By Hannah Young, Contributing Editor

Some innovative pest and disease control products, such as heat application to kill insects, are making their way to the market, according to Caltec.

California Ag Today spoke with Rudy Monnich, president of Caltec Ag, about some of the new ways California farmers are fighting pests.

caltec
Rudy Monnich with Caltec

“We have a product which is the diatomaceous earth that controls vine mealybugs and ants and mites in orchards and vineyards,” Monnich said, adding, “There is nothing more damaging than vine mealybug. In fact, Monterey County is forming a committee to be zero tolerant just for that insect pressure.”

The product is silica dioxide and will scarify the body of insects, dehydrate them, and in result kill them off in three or four days, Monnich explained.

However, the product is not a chemical, but a mineral, which significantly diminishes resistance issues.

“You don’t have the resistant issues build up,” Monnich said. “It’s also controlling thrip and whitefly in tomatoes.”

Caltec introduced the product this past spring.

Heat application can also be used by growers to combat insect problems.

“We are working with the Agrothermal people who have a machine that 300-degree to 400-degree temperatures will annihilate soft-bodied insects in tomatoes and powdery mildew in grapes,” Monnich said.

The application of heat kills the spores before signs of damage appear on the plant, Monnich explained.

This method of pest control is increasing the quality of wine, Monnich concluded.

Spotted Wilt Virus Impacting Tomatoes Again

Virus has Gotten Past Resistant Gene

By Patrick Cavanaugh, Editor

Tomato spotted wilt virus is becoming big in the central San Joaquin Valley, according to Tom Turini, University of California Cooperative Extension Farm Advisor in Fresno County for vegetable crops. The virus had earlier been spotted in lettuce, and this has caused some concern in this season’s tomato crop.

Tom Turini

“We had some concerns early in the season that we might be looking at a year where it’ll become a challenge, because we were finding it in lettuce back in February and March in the Huron area,” Turini said. “And then we notice that tomatoes were showing the virus symptoms. We had been managing tomato spotted wilt in processing and fresh market tomatoes largely with a resistance gene, and it seemed that the resistance was breaking.”

The virus is spread by thrips, and the gene in the tomato was the biggest deterrent in combating thrips.

“We were also talking about an IPM program, but the industry was leaning on this gene. This gene became a big part of their spotted wilt prevention program,” Turini said. “While sanitation of weeds was practiced, and there was some thrips management, it was really dependent upon this single gene resistance in the tomatoes, and as of 2016, we saw evidence that that gene was no longer performing.”

Because the virus can wipe out entire tomato fields, researchers are scrambling to find a new way to deter the thrip spreading the virus on tomatoes.

Rootstocks Offer Production Attributes

Tomato Rootstocks Grafting

By Jessica Theisman, Associate Editor

California Ag Today recently spoke with Brenna Aegerter, a UC Cooperative Extension farm advisor in San Joaquin County, about grafting rootstocks to tomato plants.

“Rootstocks are cut below the cotyledons, while the scions are cut above the cotyledons at an angle,” she said.

These two plants are then clipped together and go into a high humidity healing chamber for about one week.

Aegerter explained that, “In the beginning, there is no light. They gradually increase the light because they do not want to stress the plants, and so if those two angles match … then everything grows back together.”

Each tomato plant can differ depending on the rootstock that it has been grafted to. Different rootstocks have varying levels of resistance to disease and pests. Rootstock resistance does have an effect on crop yield. If all of the fruiting varieties had the nematode resistance gene, they could potentially improve their yields.

There is great success rate on grafting these tomato plants.

“We have had pretty good success, 90 percent and up,” Aegerter said.

The remaining 10 percent is because the angles were not matched up quite right and there is not enough contact between the two tissues.

“Rootstocks are for the most part, hybrids between our cultivated tomato and wild tomato species,” Aegerter explained.

Wild tomatoes are used often to bring in new genetic material due to their diversity and natural resistance. Depending on the type of tomato that is being used, the resistance can differ.

The fruiting varieties are resistant, but are resistant to a shorter list of diseases.

“These root systems are are bigger, the crown is bigger, and sometimes they aren’t even purely resistant to the disease, but just by virtue of the fact that they grow faster, they can outgrow it,” Aegerter said.

Managing DiMare Fresh Tomatoes

Season Starting for DiMare Fresh Tomatoes

By Patrick Cavanaugh, Farm News Director

DiMare Fresh is a fresh market tomato company with operations throughout California. California Ag Today spoke recently to Brian Souza, who is the in-house pest control advisor, among other things, for the company.

Souza explained how he manages the work throughout the state: “We start down south and work our way north as the season progresses. Other than being a PCA, I start in the greenhouses and manage our transplants, and just work from there.”

“We also schedule all the plantings, and manage the crops, and myself and another PCA walk the fields two times to four times a week. We always have someone in the fields every day looking, because … fresh market is sensitive, and they definitely need a lot of attention,” he said.

“We have great team members, and communicate constantly. We’re always in different areas at different times, so if there’s something I’m missing the other guys hopefully catch it, and that’s usually the case. It’s a lot of good communication and team work,” he said.

DiMare Fresh does not grow any tomatoes, but they manage a lot of growers who grow for the company.

“DiMare doesn’t own any of the property, but we do have growers that grow for us. And they are very loyal growers that we’ve had for 20, 30, 35 years.

All the rain this winter certainly can be a game changer for companies like DiMare. “We are one of the first tomato companies to start planting,” Souza said. “We love these rains, but it does bring challenges getting in as early as we normally would like to do. Sometimes we’ll have to just chance it and get our stuff in if we can.

Rains also means a lot of weeds in those fields. “For sure, there’s a lot of weeds out there, and especially with the drought we’ve noticed some newer weeds that are taking over, that are a little more drought tolerant. Horseweed and hairy fleabane are the most prominent,” Souza said.

 

 

Tomato Distributor Works With Large, Small Scale CA Farms

Morning Star Company Supplies Tomatoes to Large Distributors 

By Emily McKay Johnson, Associate Editor

Renee_Rianda
Renee Rianda with Morning Star Packing discussing the California tomato processing company

The state of California has an ample supply of tomato processors and growers. Renee Rianda, a representative with Morning Star Company, talked about the Woodland, Calif. packing industry that mainly supplies to large distributors. “Morning Star company is the overall umbrella. Morning Star is a big player.” she said, “We are unique in the fact that we are owned by one person.”

The majority of California tomatoes are used as an ingredient in other brands. Morning Star is a name that is familiar with companies such as Domino’s Pizza and Heinz Ketchup. They are not branded like companies such as Del Monte or Campbell’s, but they are used in prepared foods for grocery stores.

“Where I fit into this whole massive situation is I deal with the growers.” she said about her role with the company, “I use roughly a couple hundred growers which is not quite everybody in the state but most of them.”

The fluctuation in supply and demand for tomatoes can vary from year to year. Rianda said that is why they work with a variety of farms in California, “We have everybody from a small individual grower of everything to larger family farms that do a variety of commodities.”

Though there is not a panel or board of directors, the Morning Star Company base is efficient. “We’re very flat as far as an organization goes.” Rianda said, “Everybody has their expertise in the areas that they are best versed in.”

Rianda likes to keep herself updated at conferences around the state. In turn, she can help growers have a commodity to sell. Using the right products is key to Rianda, “That way everybody can still have ample tomatoes to eat.”

Farming in Drought: Tomato Growers Embrace the Heat

By Sarah Trent; Pacific Coast Farmers’ Markets Association

In late May, UC Davis published a drought impact report projecting 410,000 acres of farmland left fallow, 14,500 jobs lost, and a $1.7 billion hit to our state’s agricultural economy.

Since tomatoes can be a water-intensive crop, I expected that when I set out to ask farmers about the drought’s effect on their tomatoes, I would hear they were planting less, anticipating smaller yields, making changes to their seed orders for next year, and worrying about the future of their farms.

The truth?

“To be honest,” said Phil Rhodes of Country Rhodes Family Farm in Visalia, “this is our best year ever.”

Like many farmers, Rhodes is very concerned about water — the water level in his well has dropped about a foot a year since the 1990s, to the point where he must invest upwards of $50,000 to drill it deeper in the next year — but for now, the heat accompanying the drought has been a boon to his tomato crop, which came in early and strong. Rhodes brought his first tomatoes to farmers’ markets in mid-May, several weeks earlier than normal.

As long as he has water in his well, Rhodes’ farm is not impacted by water rationing by local or federal water districts. Farmers who rely on water from those sources are facing more dire circumstances: Rhodes admits that in the southern Central Valley region where his farm is located, he sees other farmers leaving fields unplanted.

Those unplanted fields may mean that vegetable farmers who have ground water access, farm in areas less impacted by the drought, or whose infrastructure, climate, and soil conditions allow for less water usage will see increased demand for their crops. So while the drought has substantial implications for California agriculture on the whole, farmers like Rhodes are doing well in spite or even because of it.

Ron Enos, who owns certified organic Enos Family Farms in Brentwood, also expects he’ll have a good year with his tomatoes. In his region, many of his neighbors are larger-scale farms growing processing tomatoes, which means that demand for his fresh tomatoes is high.

While the high-heat conditions accompanying the drought spelled trouble for his winter and spring vegetables (which do best in cooler conditions), the hot dry summer bodes well for his summer crops.

He also uses less water than many farmers in his region: over the last few years, Enos has transitioned to using a black plastic mulch in combination with drip irrigation for many of his crops, which cut his water usage to about 30 percent of what he needed before.

Another method for using less water on fruiting crops like tomatoes and squash is dry farming: a method of cutting irrigation early in a plant’s life and forcing it to rely only on existing soil moisture. Some vegetable varieties do especially well in these conditions, which result in smaller, more flavorful fruit.

While it’s near impossible to dry farm in the extreme climate of the Central Valley, it works well in coastal regions where the soil retains some moisture through the summer.