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ARS Home » Midwest Area » Morris, Minnesota » Soil Management Research » Research » Publications at this Location » Publication #118771
Title: ENVIRONMENTAL CONTROL OF DORMANCY IN WEED SEED BANKS IN SOIL

Author
item BENECH-ARNOLD, ROBERTO - IFEVA, ARGENTINA
item SANCHEZ, RODOLFO - IFEVA ARGENTINA
item Forcella, Frank
item KRUK, BETINA - IFEVA ARGENTINA
item GHERSA, CLAUDIO - IFEVA ARGENTINA

Submitted to: Field Crops Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/15/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary: Many weed seeds are dormant after they are produced. This allows them to stay viable within soil seedbanks for one or more years. Moreover, this is the primary reason why even with exceptionally good weed control, weeds continue to plague farmers every year. This paper reviews the factors that appear to govern the loss and induction of dormancy in weed seeds, including those factors that can be altered by agricultural practices. Basically, various patterns of soil temperature and moisture, sometimes coupled with exposure to light and soil nutrients, such as nitrate, are primarily associated with loss and induction of seed dormancy. Although understanding weed seed responses to these factors may not allow us to manipulate dormancy, such an understanding better enables us to predict dormancy. These predictions, however, imperfect, will provide for more informed management decisions by crop advisors and farmers. Informed diceions will increase the reliability of weed control operations and stability of crop production.

Technical Abstract: Dormancy is a common attribute of many weed seed populations and this usually hampers the task of predicting timing and extent of emergence of weeds. Both the number of established plants and the timing of emergence of a weed are strongly related to the dynamics of dormancy release of the seed population. In this paper, we discuss the different factors that affect dormancy in weed seed banks in soil, aiming to set a conceptual basis that will facilitate the construction of predictive models. From the long list of factors that are known to control dormancy under field conditions, we distinguish those that modify the dormancy level of the population (i.e. soil temperature and soil hydric conditions) from those that terminate dormancy or in other words, remove the ultimate constraints for seed germination once the degree of dormancy is sufficiently low (i.e. light, fluctuating temperatures, nitrate concentration). We also discuss the effect of agriculture practices on dormancy of weed seed populations, making reference to studies that have evinced clearly the factor(s) involved in determining a particular pattern of response. Overall, we stress the importance of clarifying, both qualitatively and quantitatively, the interaction between soil thermal and hydric conditions in the modification of the degree of dormancy of seed populations. Similarly, it is essential that we understand the extent to which such changes in dormancy comprise changes in sensitivity to factors that terminate dormancy.