Mitigation of Seed Germination Impediments in Hairy Vetch

Abstract

Hairy vetch (Vicia villosa Roth) is a promising winter cover crop for northern climates, but germination can be limited by low soil moisture conditions. Farmers may be reluctant to use hairy vetch, concerned that hard seed will emerge as weeds in succeeding crops. This work examines germination, dormancy, and viability of hairy vetch seeds from nine commercial seed sources, and evaluates the effects of mechanical scarification and ambient temperature hydropriming on the degree of hard‐seededness, germination, seed viability and seedling vigor in a range of simulated soil moisture conditions. Hydropriming increased germination by 5% across seed sources and water potentials, but reduced seedling growth by 16%. Mechanical scarification eliminated all hard‐seededness, but increased physiologically dormant seed by ∼5% and nonviable seed by ∼2% and reduced seedling growth by 39%. This work indicates that pretreatments may increase germination and reduce hard‐seededness, but reduce seed viability and seedling vigor in some seed sources.

Higher seed size and germination rate may favour autotetraploids ofVicia craccaL. (Fabaceae)

“…A hard seed coat imposing a physical exogenous dormancy in many members of Fabaceae (Rolston, ) can be softened mechanically (through abrasion or pressure), chemically (with acid) or physically (by heating, freezing, temperature fluctuation or radiation) (e.g., Ortega‐Olivencia & Devesa, ; Can et al ., ; Jacobsen et al ., ; Ates, ). While plenty of artificial softening methods were described, agents breaking dormancy under natural conditions are only partly understood.…”

Green Manure Comparison between Winter Wheat and Corn: Weeds, Yields, and Economics

“…Revenue, operational, and ownership costs were used to generate enterprise budgets (Kay et al, 2004) for each crop in the entire cropping sequence under each green manure crop treatment. Experimental yields and costs were averaged over the 3 yr of the experiment (or 2 yr of wheat; rye not used in analysis) to generate these values for the budgets.…”

“…Yearly ownership costs and operational costs, such as soil testing and lime application, were assumed for 3 yr, since this is the length of time covered by this cropping sequence. Equipment ownership, maintenance and repair costs, and land ownership costs were obtained from the Penn State Agronomy Guide (Harper, 2013), or were estimated using actual equipment prices, estimated use, and depreciation (Kay et al, 2004).…”

“…While the dollar value attributed to the green manure crop was minimal, it was included to acknowledge the potential N contribution and reduction in costs from these green manure crops. Finally, a partial budget analysis was conducted for managing these crops through the entire sequence, to compare net returns to management under each green manure crop treatment (Kay et al, 2004).…”

“…When corn follows wheat, both red clover and hairy vetch must be controlled the following spring prior to no-till corn emergence, and while hairy vetch can be terminated mechanically with a roller-crimper at flowering, control with herbicides is more common to ensure timely planting of the corn crop (Mischler et al, 2010). Grower concerns regarding hard seed and the potential of hairy vetch to become a weed in subsequent crops has also influenced hairy vetch adoption rates (Jacobsen et al, 2010).…”