Field Bindweed And Tomatoes

Field Bindweed Yield Impacts on Processing Tomatoes May be Less Than Expected

By Scott Stoddard,  County Director and UCANR Farm Advisor, Merced County

Field bindweed (Convolvulsus arvensis) is considered by many tomato growers to be the most problematic of all weeds in California production areas. Indeed, field bindweed and the closely related morningglory weeds were ranked the 8th most troublesome weeds in North America in a recent survey by the Weed Science Society of America (Van Wychen, 2019).

The rapid adoption of drip irrigation and the economic necessity of maintaining the beds and replanting with only minimal tillage for multiple seasons in processing tomatoes has created a system where field bindweed has become more prevalent. Field bindweed is extremely difficult to control because it propagates from seed and vegetatively from buds formed in the roots. Seedlings can be controlled with tillage when very young, but they become perennial very rapidly. Chemical control of seedlings is possible, but established plants are much more difficult to control.

Established plants often have a large root system relative to the amount of top growth, and thus are extremely tolerant of post emergence herbicides such as carfentrazone (Shark), glufosinate (Rely), and glyphosate (Roundup).

Bindweed is a headache not only for its persistent and pernicious growth habit and ability to reduce tomato yields, but also because it can physically stop a processing tomato harvester in the field. Vigorously growing vines can become entangled around the shaker and conveyor belts, requiring the equipment operator to shut down and manually clear out the foliage.

Several years ago, myself and other UC researchers conducted herbicide trials evaluating field bindweed control — with marginal success. In a given year and location, most of the registered herbicides in tomatoes gave only temporary suppression – about 40 – 80% bindweed control at 8 weeks after transplanting. Best results were observed where herbicides were stacked: trifluralin (Treflan) pre-plant incorporated followed by rimsulfuron (Matrix) post. Glyphosate helped in situations where the bindweed emerged early and could be applied before transplanting.

2021-09-01T21:02:16-07:00September 1st, 2021|

Tomato Roots Studied for Drought Resilient

Drought-Resilient Tomatoes – Part One

By Tim Hammerich with the Ag Information Network

The key to drought resilience in crops like tomatoes most likely lies in the roots, which are hard to study because they are of course underground. Siobhan Brady and a team of researchers at UC Davis have been working on creating a molecular atlas of tomato roots, where plants first detect the effects of drought and other environmental threats.

“We wanted to be able to first try to understand what is happening in the individual cells within those roots underground. And then to use that as a platform to try to understand similarities and differences in other root cells of other species,” said Brady.

Among many discoveries in this research, Brady and his team have been able to better understand how the exodermis helps make plants more drought resilient.

“It hadn’t really been molecularly characterized before, but it produces this barrier. And that barrier is thought to be really important for protecting the root when there isn’t enough water. In the ground. So it kind of forms a barrier to keep that water in. And so now we have the genes that we think are controlling that, and so we can study that process more and hopefully be able to breed more drought-resilient tomatoes,” noted Brady.

 

2021-06-28T18:33:53-07:00June 28th, 2021|

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.

2021-05-12T11:01:50-07:00January 18th, 2019|

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.

2021-05-12T11:05:08-07:00November 5th, 2018|

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.

2021-05-12T11:01:53-07:00August 15th, 2018|

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.

2021-05-12T11:05:10-07:00July 20th, 2018|

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.

2021-05-12T11:01:55-07:00June 18th, 2018|

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.

2021-05-12T11:05:14-07:00February 2nd, 2018|

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.

 

 

2017-02-15T15:55:44-08:00February 15th, 2017|

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.”

2016-06-19T21:36:22-07:00June 16th, 2016|
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