Depletion of the weed seed bank by stimulating germination during winter months and subsequently exposing the seedlings to adverse air temperatures is a possible means of controlling weeds in small-scale horticultural operations. Johnsongrass [Sorghum halepense (L.) Pers.], hemp sesbania [Sesbania exaltata (Raf.) Rydb. ex A.W. Hill], and barnyardgrass [Echinochloa crus-galli (L.) Beauv.] were seeded in soil trays and maintained for 4 days at 4 or -12 °C, then heated to 32 °C for 4 days using electric heating pads. Germination percentages, after heating soils, were: 55% and 70% for hemp sesbania, 82% and 72% for barnyardgrass, and 45% and 55% for johnsongrass, respectively; for seeds kept at -12 and 4 °C, respectively. Subsequent exposure of seedlings to -12 °C for 7 days killed all seedlings, while exposure to 4 °C killed only 18% to 28%. The temperature regimes of -12 °C for 4 days, and 32 °C for 4 days followed by -12 °C killed 95%, 78%, and 68% of the johnsongrass, hemp sesbania, and barnyardgrass, respectively.
Search Results
Rakesh S. Chandran and Megh Singh
Gladis M. Zinati
A question/answer discussion session was conducted at the conclusion of the workshop “Pest Management During Transition to Organic Farming Systems”. The following categories were used to summarize the discussion: 1) questions and answers related to cultural and biological practices and their effects under various climatic conditions, 2) recommendations for pest management, and 3) future research needs. While many tactics are available, selecting and adopting the most suitable approach depends on soil conditions of the land, location, and the availability of the resources at affordable prices. Definitely, more research studies are needed on 1) weed seed banks under various cultural practices at different regions, 2) relationships between soil nutrients, and pest control, and 3) approaches to increase profitability of organic production during the transition period.
Shuresh Ghimire, Annette L. Wszelaki, Jenny C. Moore, Debra Ann Inglis, and Carol Miles
at both locations in both years, indicating that there was a significant weed seed bank in the plots and the mulches indeed provided a barrier to weed emergence and/or growth. Other studies also have found that plastic BDMs controlled weeds equal to
Suzanne P. Stone, George E. Boyhan, and W. Carroll Johnson III
Georgia; however, for larger growers using weed-control equipment, these results may not be applicable. In addition, unique local conditions such as weed species, the weed seed bank, weather conditions, and previous management have an impact on weed
Haley Rylander, Anusuya Rangarajan, Ryan M. Maher, Mark G. Hutton, Nicholas W. Rowley, Margaret T. McGrath, and Zachary F. Sexton
also kills emerged annual weeds by chopping them and leaving them to dry out on the soil surface ( Nakamoto et al., 2006 ). Tarping can kill emerged weeds ( Birthisel, 2018 ; Lounsbury et al., 2018 ) and could help farmers manage weed seed banks for
Adam Montri and J.A. Biernbaum
removal of existing groundcover, reduction of the weed seed bank, increasing soil organic matter (SOM) and fertility, and if necessary, grading and adjusting the slope for rain water removal. It is recommended that site and soil preparation begin 1 year or
Marco Fontanelli, Luisa Martelloni, Michele Raffaelli, Christian Frasconi, Marco Ginanni, and Andrea Peruzzi
-tolerant crops [e.g., maize ( Zea mays ), onion ( Allium cepa ), and garlic ( Allium sativum )]. The stale seedbed technique can be an effective weed control measure because it depletes the weed seed bank, which interferes with the crop during the growing season
Gina M. Angelella and Megan E. O’Rourke
to stimulate weed growth (B. Glennon, personal communication), but this may be affected by site-specific weed seed bank communities ( Chauhan et al., 2006 ; Oegema and Fletcher, 1972 ; Yenish et al., 1996 ). To inform pollinator habitat
Alyssa H. Cho, Carlene A. Chase, Danielle D. Treadwell, Rosalie L. Koenig, John Bradley Morris, and Jose Pablo Morales-Payan
suppressing weed populations and limiting or preventing additions to the weed seed bank, a cover crop can provide soil stability, improve nutrient cycling, reduce leaching and runoff of nutrients and pesticides, and provide nutrients such as nitrogen, thus
Alyssa H. Cho, Alan W. Hodges, and Carlene A. Chase
cycle is often left as a weedy or clean (usually with tillage) fallow. Although tillage suppresses weed populations to an extent, tillage can build the weed seed bank and spread weed seeds ( Froud-Williams et al., 1983 ). Additionally, tillage is