Post originally published in Pennsylvania Certified Organic's Organic Matter Quarterly Newsletter Spring 2017 Issue.
No-Till and Insectary Strips for Organic Cucumber Production
Researchers share organic management tips on maximizing yields, decreasing pest damage, and eliminating wilt
Dr. Gladis Zinati, Rodale Institute's lead scientist on a research and demonstration project titled, Using Roller Crimper Technology, Cover Crops, and Insectary Strips to Improve Organic Vegetable Cropping Competitiveness in Pennsylvania, and Dr. Andrew Smith, Director of Vegetable Systems Trial, shared promising first-year results during a recent Pennsylvania Association for Sustainable Agriculture (PASA) Conference workshop. Attendees left the workshop inspired and many indicated that they would adopt the revolutionary tactics of using insectary strips as a natural system to increase populations of beneficial insects and reduce tillage by using rolled crimped cover crops.
The two-year research project is being performed at the Rodale Institute and at an off-site farm, PCO-certified Spiral Path Farm, with assistance from Mike Brownback, cooperating organic vegetable producer. The main goal of this research is to improve the competitiveness of organic specialty crops for Pennsylvania growers. The objectives are to evaluate the impact of rolled cover crop mulch compared to plastic mulch with and without the inclusion of flowering insectary strips on organic cucumber yield, striped cucumber beetle damage, and population densities of beneficial insects.
The cucumber beetle feeds on cucumber plant leaves, flowers and fruits and causes scars on cucumber fruits that impact marketability. This pest is also a vector for a bacterium pathogen (Erwinia Tracheiphila) that causes plant wilting and has the potential to eliminate an entire crop within a few day.
The purpose of integrating insectary strips into organic cucumber production systems is to provide habitat for ground predators (ground beetles and wolf spiders) and aerial beneficial insects including soldier beetles, lady bugs, honey bees, bumble bees, and two cucumber beetle parasitoids, a tachinid fly, and a braconid wasp. Insectary strips, each 5ft by 30ft, were established in Fall 2015 with alfalfa as a base plant and oats as a nursing crop. A suite of plants such as bouquet dill, sacred basil, resin calendula, alyssum, lemon balm, fava bean, peas, sunflower was transplanted throughout April and May 2016.
Two cover crop mixtures were tested in this project. A rye/hairy vetch (R/HV) and a rye/field Pea (R/FP) mixture. They were either rolled-crimped for no-till production or tilled-in covered with plastic mulch. Cucumber plants were grown without any additional fertilizers to assess the impact of nutrient release from tested cover crops.
Insectary strip such as this one with bouquet dill, resin calendula, alyssum, sacred basil, lemon balm, fava beans and peas provide habitat for beneficial insects.
A rotational no-till layout for organic cucumber production pictured at the Rodale Institute’s research farm in Kutztown,PA.
Dr. Gladis Zinati | Associate Research Scientist
Dr. Andrew Smith | Director of Vegetable Systems Trial
In a nutshell, results showed that:
• Rolled-crimped cover crops covered the soil surface well throughout the season and reduced weeds.
• Irrespective of cover crop mixture, cucumber yields were optimum and ranged between 400 and 670u/acre in plastic much, and plants in rolled-crimped beds would require additional fertilization to achieve maximum yields.
• The inclusion of insectary strips increased premium organic cucumber yields in the plastic mulch treatments.
• Ground beetle populations were highest in insectary strips, the grass perimeter and in rolled mulch with and without insectary strips.
• Ground beetles were lowest in plastic mulch without insectary strips.
• Significantly lower densities of the striped cucumber beetle were found in rolled mulch compared to plastic, and more importantly, the cucumber plants did not show any symptoms of wilting.
This project funded by a Pennsylvania Department of Agriculture Specialty Crop Block Grant is beginning its second year. For more information on the project, please contact Dr. Gladis Zinati, Associate Research Scientist, Rodale Institute at Gladis.Zinati@RodaleInstitute.org | 610-683-1402