Organic Management for Horticulture Crops

The demand for fresh, local, and organic produce continues to rise, while area growers are seeking to produce quality fruit and vegetables.  Here at the West Central Research and Outreach Center, one of the goals within the Horticulture Department is to support Minnesota's small fruit and vegetable growers through applied research.  We've tackled many of the growing concerns that face producers: weed pressures, pests and disease, soil health, maximizing profit, and cultivar selection.  Our hope is that our research findings can be helpful to those seeking to start or improve their own growing systems.

Cover Crops in High Tunnel Vegetable Production

High tunnel mid seasonHigh tunnels are a great tool for growing warm weather crops in Minnesota.  The plastic captures heat from the sun so the growing season can start earlier, end later, and get hotter.  These conditions help growers produce high quality early and late season tomatoes and peppers as well as specialty tropical crops like ginger and turmeric.  High tunnels also improve crop quality by shielding fruit from rain and hail damage and preventing soil splashing which can cause disease. 

While high tunnel production is characterized by increased productivity, due to intense cultivation strategies and intensive fertilization, these practices lead to some unusual soil health problems such as high salinity and low organic matter content.  The WCROC high tunnel project evaluates inclusion of short-lived, fall planted cover crop legumes to improve soil fertility and quality in high tunnel environments.

Grit Weeding for Weed Control

Weed management, particularly within rows of perennial fruit plants, is challenging.  Because of the perenniality of these crops, rotation and tilling are not options. Growers might typically look to herbicides for in-row weed management; however, most herbicides are not labeled for use in fruit crops. For the few herbicides labeled, there are concerns about cost, environmental effects, and efficacy of products, especially on young plantings when crops are most vulnerable to weed pressure.   

We are embarking on a new project using an adbrasive grit to blast out weeds within rows of perennial fruit plants such as raspberries, apples, and grapes for with-in row weed management as an alternative to hand weeding, which can be time consuming and labor intensive.

Spotted Wing Drosophila

Spotted wing drosophila (Drosophila suzukii, SWD) is an invasive fruit fly that has been present in Minnesota since 2012. Crop losses have been reported as high as 40, 20 and 50 percent in blueberry, strawberry and raspberry, respectively. At the WCROC, we will be investigating the efficacy of innovative and alternative management techniques in raspberries to control SWD.

Strawberry Research

Strawberry research has been ongoing at the WCROC in collaboration with the Department of Horticultural Science for the past 20 years, both with perennial June-bearing cultivars and day-neutral varieties (grown as annuals). While the traditional June-bearing varieties produce fruit from early June through early July, our day-neutral low tunnel system offers high quality fruit from July to October, a non-traditional time of year in Minnesota. This system for growing strawberries offers great potential for farmers: June-bearing varieties have an average yield of 5,500 lbs/acre of fruit, while the day-neutral low tunnel strawberries have produced from 8,600 lbs/acre in 2017 up to 17,300 lbs/acre in 2016.

Day-neutral Strawberries in a Low-Tunnel System

Day-neutral low tunnel strawberriesAvailability of locally grown strawberries is extremely limited in the Upper Midwest due to the short growing season and cultivars with short harvest windows.  We have developed a growing system using day-neutral strawberry varieties using a low-tunnel system, which not only produces quality fruit, but extends the strawberry season into October.

June-bearing Strawberries

Evaluation of several June-bearing strawberry varieties helps us determine superior cultivars for growers in Minnesota and surrounding areas.  The June-bearing strawberry trial at the WCROC is one of three sites around the state.  Cultivars introduced from this project will have demonstrated their adaptation to wide range of climatic conditions common to Minnesota.  They will have also been screened for fruit quality and for tolerance to red stele rot, black root rot, leaf scorch, leaf spot and powdery mildew. 

Biodegradable Mulch

Minnesota small-fruit growers need an environmentally acceptable system for producing annual strawberries to increase the supply of this high-value specialty crop. The low tunnel system requires hoop-like structures that go over the rows of strawberry plants. In addition, the strawberry plants must be planted into some type of mulch for adequate weed control and to maximize plant growth.  Previously, we evaluated plastic mulch and landscape fabric for weed control, a challenge in strawberry production. However, in 2017 we evaluated the effectiveness of biodegradable mulch in the low-tunnel system for day-neutral strawberries.