Weed Management

Creating Climate Resilient Organic Systems by Enhancing Arbuscular Mycorrhizal Fungi Associations

While the majority of carrots are cultivated in California, recent droughts and water use restrictions may impact the success of future crops. Even in states such as Wisconsin, where water is more abundant, crops still must overcome oscillating soil moisture regimes due to differences in soil drainage, water-holding capacity, and microclimate conditions, as well as the anticipated drier summers which are predicted to increase with climate change.

Field Evaluation of Designed Compost Extracts for Organic Weed Suppression

Organic vegetable growers need practical and cost-effective technology to reduce weed pressure and yield losses. In 2013-2014, OFRF funded Dr. Gladis Zinati at the Rodale Institute to perform laboratory and greenhouse trials on the weed suppressing ability of chemically- and biologically-designed compost extracts (DCE). Dr. Zinati found that DCEs with lower nitrate levels and greater nematode-to-protozoa ratios significantly reduced lambsquarter weed seed germination by 32% without affecting crop seed percent germination.

Development of weed control methods and irrigation requirements for organic medicinal herb production in New Mexico, 2003-2004

 Small-scale and family-oriented organic growers must be continually innovative and efficient in their operations in order to remain in business. One strategy for small and organic farmers is development of niche markets and specialty or high-value alternative crops, such as medicinal herbs. The American Southwest has a large number of native medicinal herb species that have been used traditionally by indigenous and Hispanic cultures. By and large, these species have been wild-harvested from native stands, mostly for personal, family, or local use.

Effects of organic alternatives for weed control and ground cover management on tree fruit growth, development and productivity

Organic fruit production in the US, especially the western regions, is expanding. The increase is occurring for both economic and ecological reasons. Current market conditions dictate that organic apple growers produce large, flavorful, high quality fruit. Large, high quality fruit receive price premiums and market acceptance whereas small fruit can be difficult to sell, even at lower prices. To grow large fruit, trees must be unstressed and provided with adequate water and nutrition. Weeds can compete with fruit trees for both water and nutrients.

Targeted Mowing to Increase Allelopathy of Rye Cover Crop in a Tomato Production System

This project examined whether targeted mowing of winter rye cover crop (Secale cereale L.) would increase its weed suppression ability by increasing levels of rye’s major allelochemicals, Hydroaxamic acids (Hx), and subsequently increase crop yield in an organic tomato production system. The project was conducted on organic farms in Upper Marlboro (2003), and Beltsville (2004), Maryland, using a rye cover crop that was grown as a monoculture and as a mixture with crimson clover, and black mulch. 

Evaluation of In-Row Weed Cultivators in Organic Soybeans and Corn

Objectives

1. To investigate the abilities of six in–row weeding implements to control in-row weeds in organic soybeans and corn. The initial selected six implements were reduced to five after preliminary trials showed that the Bezzerides Cultivator System with spyder set and spring hoe, was similar with the Bezzerides Cultivator System with spyder set and torsion weeders. This change was made with the agreement of the farmer. Also it was decided to use the Williams tool system as the tine weeder without the optional side knives offered.

Weed Suppression Using Brassicaceae Cover Crops in Organically Grown Peppers

The original objectives of this project as stated in the proposal were to: 1) Test the effectiveness of high glucosinolate-containing meals at controlling soilborne diseases (damping-off and white mold of lettuce) in an organic farming system. 2) Determine the influence of these materials on N cycling processes in organic systems. 

The effect of cover crop seeding rate, planting arrangement, and mixture composition on cover crop performance and weed management on organic vegetable farms on the central coast of California

OBJECTIVES

(1) To determine the effect of cover crop seeding rate and planting arrangement on cover crop biomass production, cover crop canopy development, and weed suppression. Seeding rates included a standard rate (1x) typical on farms in the area, and higher rates (2x, 3x). Plant arrangements included a one-way versus a grid drilling pattern. This was the objective of trials 1 to 3.

Eff ectiveness and economic impact of weed control systems in organic garlic production

Project objectives were:

a) To determine which weed reduction system is the most economically effective by:

1) Determining total labor and material cost for each weed control system.

2) Determining effectiveness of each weed control system by recording percent weed species emergence and percent weed cover throughout the year.

3) Determining total garlic yield for each weeding system.

4) Determining garlic quality, as measured by bulb size, for each weeding system.