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Grafting May Aid Watermelon Crop

WatermelonsThe watermelon crop has declined dramatically in Washington because of disease, but Washington State University researchers are developing a solution that involves grafting watermelon plants onto squash and other vine plant rootstocks. “We’ve lost about a third of our state’s watermelon production over the last 10 years because of Verticillium wilt,” said Carol Miles, a professor of vegetable horticulture at the WSU Northwestern Washington Research and Extension Center in Mount Vernon. “Growers have switched to other crops that are less susceptible.” The fungus also affects tomatoes, potatoes, eggplant and many other crops and plants. “Grafting is very old technology, going back over 1,500 years in China,” said Miles. “Farmers in Japan have been grafting watermelon since the 1920s. In the Mediterranean region, farmers have been grafting watermelon, tomato and eggplant for almost 20 years. We just need to find out what works best for our region, and we’ll solve the Verticillium wilt problem.”

This article appears in the May 2015 issue of Acres U.S.A.

Preventing Tomato Blossom-End Rot

800px-Blossomendrot

Plants are subjected to numerous environmental stresses — drought, extreme temperatures and excess light can all affect plant growth and quality. Looking for methods to improve the quality of tomato plants, researchers at the University of Tennessee turned to abscisic acid (ABA), a plant hormone known to help plants acclimate to these types of severe environmental stresses. The research results and recommendations for growers were published in HortScience.

According to the study’s corresponding author Carl Sams, ABA can have a positive effect on nutritional fluxes in plants; for example, it can promote the uptake of calcium in tomato plants. Adequate levels of calcium in tomato fruit have positive effects on fruit quality — specifically firmness — while insufficient calcium uptake and movement in tomato plants can result in a disorder called blossom-end rot. Blossom-end rot often occurs in plants that have an adequate calcium supply but are grown in challenging environmental conditions such as humidity, high light intensity and high temperatures, all of which inhibit transport of calcium to plants’ rapidly growing distal fruit tissue. Blossom-end rot can also occur when plants experience increased demand for calcium in the early stages of fruit development.

This summary appears in the March 2015 issue of Acres U.S.A.

Organic Fire Blight Control

early blight leafOregon State University researchers have proven the effectiveness of two organic alternatives for controlling fire blight. Scientists found that spraying a yeast-based product and new water-soluble copper products at the beginning of the growing season provided protection from the bacterial disease. Spread by bees and rain, fire blight remains dormant in trees over winter and infects flowers in spring.

Once infected, growers can only stop the disease by cutting out infections, which can prove fatal in some cases. In OSU trials, researchers tested the commercially available Blossom Protect, a yeast that clings to apple blossoms and pears and prevents colonization by fire blight bacteria. In apples, it was 90 percent effective in controlling fire blight when sprayed after lime sulfur to reduce crop load.

Copper is another option in fighting fire blight, and it has been used for for almost a century. Heavy applications however can be toxic to trees and can create rough blemishes on fruit, known as russeting. New water-soluble copper products, such as Cueva and Previsto, contain low concentrations of the metal, which minimizes its negative effects while still combating fire blight. The research team also prepared a webinar on non-antibiotic treatment of fire blight, available here. This information was first shared in the October 2014 issue of Acres U.S.A.

Organic Fire Blight Control

apple-tree-fire-blightOregon State University researchers have proven the effectiveness of two organic alternatives for controlling fire blight. Scientists found that spraying a yeast-based product and new water-soluble copper products at the beginning of the growing season provided protection from the bacterial disease. Spread by bees and rain, fire blight remains dormant in trees over winter and infects flowers in spring. Once infected, growers can only stop the disease by cutting out infections, which can prove fatal. In OSU trials, researchers tested the commercially available Blossom Protect, a yeast that clings to apple blossoms and pears and prevents colonization by fire blight bacteria. In apples, it was 90 percent effective when sprayed after lime sulfur to reduce crop load. Copper has been used for fire blight for almost a century, but heavy applications can be toxic to trees or create rough blemishes on fruit, known as russeting. New water-soluble copper products, such as Cueva and Previsto, contain low concentrations of the metal, which lessens its negative effects while still combating fire blight. The research team prepared a webinar on non-antibiotic treatment of fire blight, bit.ly/FireBlightWebinar.

This article appears in the October 2014 issue of Acres U.S.A.

Gut Microbiota Linked to Autism

autism-spectrum-disorderChildren with autism spectrum disorders (ASD) have significantly different concentrations of certain bacterial-produced chemicals, called metabolites, in their feces compared to children without ASD. “Most gut bacteria are beneficial, aiding food digestion, producing vitamins, and protecting against harmful bacteria. If left unchecked, however, harmful bacteria can excrete dangerous metabolites or disturb a balance in metabolites that can affect the gut and the rest of the body, including the brain,” said Dae-Wook Kang of the Biodesign Institute of Arizona State University. Increasing evidence suggests that children with ASD have altered gut bacteria. In order to identify possible microbial metabolites associated with ASD, Kang and his colleagues looked for and compared the compounds in fecal samples from children with and without ASD. They found that children with ASD had significantly different concentrations of seven of the 50 compounds they identified.

This article appears in the July 2014 issue of Acres U.S.A.

Commercial Organic Grafted Tomato Production

TomatoCommercial organic tomato production is lucrative but challenging. Marketable fruit can bring a good price but yield is reduced by crop disease and insect pressure, drought and flooding, non-optimal nutrient supplies and other factors. Grafted tomato plants can be less susceptible to some of these stresses, particularly certain nematodes and soilborne diseases. There is also evidence that grafted tomato plants tolerate unwanted extremes in soil moisture, low soil fertility and high soil salinity levels more effectively than ungrafted plants.

Grafting creates a direct, physical and one-time ‘hybrid’ plant with traits of the rootstock and scion varieties it contains. Rootstock and scion variety selection is the first step in using grafted tomato plants and the selection should be done very carefully based on traits that are important to you on your farm. Learn more about how thousands of combinations affect production outcomes and what Ohio State University is researching in the January 2014 issue of Acres U.S.A.