Fruit and Vegetable News

Eric Burkness, Mary Rogers and Bill Hutchison, Departments of Horticultural Science and Entomology Spotted wing drosophila flies investigating a raspberry. Photo:Hannah Burrack, North Carolina State University, Bugwood.org In a typical growing season, spotted wing drosophila (SWD) trap catch begins at approximately 755 degree days (DD), using a 50 ° F base temperature, as the flies begin seeking out and attacking a wide range of wild and cultivated small fruit that begins to ripen in mid to late June. In 2023, we have already surpassed 755 DD at both the Rosemount and St. Paul experiment stations in MN with DDs through June 22 nd of 920 and 928, respectively. As of June 22, we still have not detected SWD in either of those trapping locations .  Previous research has shown that SWD mating, and egg lay, will be reduced and may cease when temperatures exceed 86 ° F and as temperatures increase eggs that are laid may not hatch. Despite the adverse weather conditions, SWD infestati...

Over time, high tunnels tend to accumulate salts, which can drive up the alkalinity and pH of the soil. Acidifying irrigation water is one way to address this problem, and it can be done with varying degrees of investment and technology. Understanding the problem When we apply fertilizer, compost, and manure to our soil, we are often adding salts. Calcium, magnesium, potassium, sodium, and ammonium are all examples of salts that we commonly add to agricultural soils. Typically, acidic rain water washes these salts out of the soil to keep things balanced. However, in tunnels where we lack access to rain, this washing out process does not happen. Further, sometimes the groundwater we use to irrigate in tunnels is also rich in salts. When salts build up in the soil, the alkalinity of our soil also increases. Alkalinity refers to the ability of water to neutralize acids and bases, and thus maintain a stable pH. Over time, this can lead to an increase in the pH of soil in high tunnels. This...

  Annalisa Hultberg, Extension Educator, food safety If you are using surface water sources like ponds, creeks, rivers or water that has been collected from roofs for irrigation of your produce, remember that these sources of water are open to the environment and can be contaminated with human pathogens like Salmonella and toxigenic  E. coli  that can sicken people if it is on your produce. Even well water, though much more protected than surface water, can become contaminated if your well is compromised.  Read on for tips to reduce the potential for water to contaminate your fresh produce this season. What are the risks with using surface water for irrigating fruits and vegetables? While surface water like water pumped from a pond, stream, creek or river might seem like a cheaper alternative to ground water, this water must be used with caution. Water used for irrigation can be a source of contamination for our fruits and vegetables if the water contains human patho...