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Vetch Cover Crop Recommended for Organic Zucchini

Illustration_Vicia_sativa0In a new study, the popular cover crop vetch (Vicia sativa L.) was used in a two-year field experiment designed to determine the effects on organic zucchini yield and quality of vetch residue management strategies incorporating green manure using a roller-crimper (RC) and organic fertilizers.

To allow for timely crop rotation in organic farming, the growing cycle of cover crops is often terminated before natural maturity using mechanical chopping and/or plowing, field disking, mowing or crushing with a roller-crimper. Innovative conservation tillage production systems using RC technology to end cover crops are gaining popularity. The technique uses one or two passes of the RC to flatten the cover crops, leaving a thick mulch layer into which the next crop is sown or transplanted. The thick mulch hinders the development of weeds during the critical growing period, contributes to reduced soil erosion and increases soil moisture and fertility.

Researchers used municipal solid waste compost, anaerobic digestate and a commercial organic fertilizer in the field experiments designed to determine yield, yield components, crop quality, and soil nutritional status in organic zucchini fields in southern Italy.

“Our results showed that zucchini yield was influenced positively by the vetch residue management strategy, although the response was significantly different between years,” the scientists said. “The vetch cover crop increased marketable zucchini yield in the first year by 46.6 percent compared with the fallow treatment, indicating that this fertility-building crop could reduce off-farm nitrogen (N) fertilizer input for subsequent crops. Averaging over two years of the experiment, marketable zucchini yield increased by 15.2 and 38 percent with the roller-crimper mulch and green manure plow-down, respectively, compared with the fallow treatment, although differences were significant only in the first year.”

The application of organic fertilizers in vetch management plots increased marketable zucchini yield by 21.8 percent in the first year compared with the unfertilized control.

This article appears in the December 2013 issue of Acres U.S.A.

Weed Control with Flame Cultivation

cranberry & flameUniversity of Massachusetts scientists designed a study using flame cultivation (FC) techniques for weed control in cranberry crops. The results, published in HortScience, show promise for integrating the weed control technique into “certain situations,” including organic farming. The team tested three types of handheld propane torches and varying exposure times on several species of perennial weeds. “We thought that flame cultivation would cause damage to cranberry plants and that damage would increase with increasing exposure duration and vary by flame cultivator tool used,” noted Hillary Sandler, the study’s corresponding author. Although the results showed minor response differences between the cranberry varieties tested, all varieties showed recovery from flame cultivation damage, irrespective of which tool was used or the duration of exposure.

Flame Cultivation Offers Economic Alternative to Glyphosate

“Our economic analysis showed that the time and cost of using an open flame torch for spot control of weeds was similar to that of the common practice of using a wick applicator to apply glyphosate to weeds,” the researchers noted.

This article appears in the November 2013 issue of Acres U.S.A.

Glyphosate-Resistant Pigweed Project

Weed control Amaranth-pigweedPalmer amaranth, commonly known as pigweed, is one of the most common — and problematic — weeds in soybean crops across the southern United States. Because it is difficult to control, it is best to combat the weed before it emerges. The journal Weed Technology offers results of field tests of resistant Palmer amaranth in glyphosate-resistant soybean crops in Arkansas conducted over a two-year period. In this study, 250,000 glyphosate-resistant pigweed seeds were incorporated into the soil, and their emergence was evaluated five times during the growing season. Three farming practices were tested — deep tillage, planting a cover crop of rye and doublecropping a field with wheat and then soybeans in the same growing season.

This article appears in the October 2013 issue of Acres U.S.A.