Nitrogen fertilizer trials at Hancock indicate that ESN® has performed well as of 30 days after emergence (DAE). The main fertilizer treatments will be split into sub-treatments where some plots will receive additional N fertilizer applications (in 30 lb-N/ac intervals) based on rainfall events to assess how well ESN® compares to conventional fertilizer with supplemental N applied. The ESN® was applied 100% at emergence while the ammonium sulfate (AMS) and ammonium nitrate (AN) treatment were split applied (⅓ of N as AMS at emergence, ⅔ of N as AN at tuberization). At 30 DAE, the ESN® had greater average petiole nitrate concentrations across all N rates.
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Radio clip and short news article on Wisconsin Public Radio from Tuesday, July 11th. Large scale producers with overhead irrigation systems are doing quite well, especially potato and sweet corn. However, fresh market growers using drip irrigation have struggled to keep up with demand and irrigation frequency.
A great evening north of Pardeeville, WI for the Organic Vegetable Twilight Field Tour at Norman Miller’s Farm. It is clear that the drought conditions during the 2012 field season have caused issues for even the irrigated crops. Much of the evening focused on insect issues (covered by Russ Groves), disease issues (covered by Amanda Gevens) and physiological issues pertaining to fruit set and fruit quality.
Several growers brought along peppers with blossom end rot (Fig. 1). Blossom end rot can be related to calcium (Ca) deficiency. However, most Wisconsin soils are not deficient in Ca. Other factors such as excess N or K application or lack of root development were ruled out as well. The main cause of blossom end rot appears to be water stress. Even with drip irrigation supplying water to the crops, it has been difficult to provide enough water. Water stressed plants are not able to translocated Ca from leaf tissue to fruit, causing the physiological disorder.
Another issue observed that growers field was split melons (Fig. 2). It is unclear the actual cause, our best guess as a group (after considerable questioning of the farmer) was that it was caused by uneven irrigation and heat and water stress during non-irrigated periods. There were also specific questions about odd shaped fruit for cucumber and tomato. The root cause of these physiological symptoms are all likely the same. It has been difficult to supply enough water consistently throughout the day to keep plants from experiencing stress. Growers who only irrigated every other day have seen the most fruit quality issues.
Figure 1. Blossom end rot in pepper
Figure 2. Split melon caused by heat (?)/water (?)/irrigation managment (?)
Four on-farm field trials were conducted this year to evaluate nitrogen (N) fertilizer need for sweet corn. The first field site is ready to be harvested. The harvest season has begun!
New research evaluating the agronomic and environmental effects of slow-release fertilizers and urease inhibitors in potato production will begin on Monday, April 27th. Fields will be planted at the Hancock Agricultural Research Station. The funding for this research was provide by the Wisconsin Potato and Vegetable Growers Association (WPVGA).