Italian ryegrass growth and production from
positionally selective applications and sublethal rates of a
nonselective herbicide were compared to growth and
production when treated with diuron applied preemergence as
a broadcast treatment and safened by activated carbon
applied over the crop row. In the positionally selective
treatments, herbicide spray was directed to leave an
untreated zone over the crop row at planting. Growth
analysis indicated no detectable differences when Italian
ryegrass safened by directed spray was compared to Italian
ryegrass safened by activated carbon. The major difference
between systems was greater weed control in the crop row for
carbon-safened treatments.
The non-safened application superimposed sublethal
diuron rates over Italian ryegrass and rattail fescue grown
in varying densities and proportiors. Growth analysis of
monoculture stands indicated differences due to planted
density, species, and herbicide, whereas growth analysis of
plants grown as space-planted individuals indicated
difference due to species only. Diuron at the rates applied
did not affect seed yield or above ground dry weight.
Soil samples were taken in crop rows where diuron was
applied as directed spray or broadcast spray safened by
carbon. Samples were assayed and soil profile
concentrations mapped. To assist future investigators'
understanding of the role rainfall plays in herbicide
movement from directed applications, elementary rainfall
depth and occurrence models were examined. The Markov and
mixed-exponential models adequately described rainfall
occurrence and depth patterns for Corvallis, Oregon. / Graduation date: 1992
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/36537 |
| Date | 23 January 1991 |
| Creators | Reyes, Carlos C. |
| Contributors | Mueller-Warrant, G. W. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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