Factors Affecting Weed Seed Devitalization with the Harrington Seed Destructor

Abstract

The Harrington Seed Destructor (HSD), a novel weed control technology, has been highly effective in Australian cropping systems. To investigate its applicability to conditions in western Canada, stationary threshing was conducted to determine the impact of weed species, seed size, seed number, chaff load, and chaff type on efficacy of seed destruction. Control varied depending on species, with a range of 97.7% to 99.8%. Sieve-sized volunteer canola seed had a linear relationship of increasing control with increasing 1,000-seed weight. However, with greater than 98% control across all tested seed weights, it is unlikely that seed size alone will significantly influence control. Consistently high levels of control were observed at all tested seed densities (10 seeds to 1 million seeds). The response of weed seed control to chaff load was quadratic, but a narrow range of consistently high control (>97%) was again observed. Chaff type had a significant effect on weed seed control (98% to 98.6%); however, seed control values in canola chaff were likely confounded by a background presence of volunteer canola. Overall, the five parameters studied statistically influence control of weed seeds with the HSD. However, small differences between treatments are unlikely to affect the biological impact of the machine, which provides high levels of control for those weed seeds that can be introduced into the harvester.

Opportunities and challenges for harvest weed seed control in global cropping systems

“…To determine suitability of chaff processing during harvest for controlling the seed of problematic weeds, stationary threshing evaluations have been conducted using a HSD cage mill. High levels of seed destruction (>97%) were observed for kochia, green foxtail, cleavers, volunteer canola and wild oat (Table ) . In studies using an iHSD mill (Soni N et al , unpublished), there were similarly high seed destruction levels (>98%) for feral rye, downy brome and jointed goatgrass.…”

“…High levels of seed destruction (>97%) were observed for kochia, green foxtail, cleavers, volunteer canola and wild oat ( Table 2). 59 In studies using an iHSD mill (Soni N et al, unpublished), there were similarly high seed destruction levels (>98%) for feral rye, downy brome and jointed goatgrass.…”

Herbicide Resistance Management: Recent Developments and Trends

“…In the last five years, substantial research and development efforts have been conducted in Canada and the U.S. to evaluate the potential of HWSC for key troublesome weed species, such as wild oat ( Avena fatua L.) and cleavers ( Galium spp.) in the Great Plains [43,44,45], and Palmer amaranth ( Amaranthus palmeri S. Watson) and barnyardgrass ( Echinochloa spp.) in the Midwest or southern U.S. [46].…”

Current outlook and future research needs for harvest weed seed control in North American cropping systems

“…5,31 Several efforts to assess the efficacy of impact mills to target weeds of North American cropping systems have demonstrated their great potential for use as an HWSC tactic for IWM. 15,28,32 In a recent study, an impact mill was highly effective in destroying seeds of ten weed species common to soybean fields in the Midwest and Mid-Atlantic regions of the USA, with 93.5-99.8% weed seed destruction in 2015 and 85.6-100% in 2017. 28 The difference between years was likely due to differences in the weed species tested and environmental conditions.…”