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ARS Home » Pacific West Area » Pendleton, Oregon » Columbia Plateau Conservation Research Center » Research » Publications at this Location » Publication #147777

Title: SEED-SOIL CONTACT AND THE ROLE OF VAPOR IN GERMINATION

Author
item Wuest, Stewart

Submitted to: Columbia Basin Agricultural Research Annual Report
Publication Type: Other
Publication Acceptance Date: 3/1/2003
Publication Date: 6/1/2003
Citation: WUEST, S.B. SEED-SOIL CONTACT AND THE ROLE OF VAPOR IN GERMINATION. COLUMBIA BASIN AGRICULTURAL RESEARCH ANNUAL REPORT. 2003.

Interpretive Summary: Seed-soil contact has been assumed to be the most important factor for rapid transfer of water from soil to seed. Recent research demonstrated that seed is capable of germinating without soil contact, and that 85% or more of the water absorbed by seed can be directly attributed to vapor. A new appreciation for the capacity of soil atmosphere to supply water vapor to seed should prove useful in future efforts to improve seeding equipment. Earlier publications of this research have attracted the attention of seed technologists and the general science community.

Technical Abstract: Seed-soil contact has been assumed to be the most important factor for rapid transfer of water from soil to seed. Recent research demonstrated that seed is capable of germinating at nearly the same rate when the only source of water is vapor. This finding places in doubt the concept of seed-soil contact. The research concluded that more than 85% of the water absorbed by seed can be directly attributed to vapor. Tests of wheat, barley, mustard, and pea seed showed only small differences in days to germination between seed in excellent soil contact and that lacking any soil contact. In the past, researchers have underestimated the contribution of vapor because of a lack of appreciation for the effects of distance on vapor diffusion rates.