Probability Maps for Risk Asessment in a Patchy Weed Control

Probability Maps for Risk Asessment in a Patchy Weed Control Weeds were monitored during April 1996 along a 36 m×36 m grid within a 21 ha winter wheat field to detected whether black bindweed (Fallopia convolvulus L.), cleavers (Galium aparine L.), which are important weeds in cereals, and total weed densities reached economical thresholds for control. The geostatistical method of block kriging with indicator values (1 if below the threshold and 0 otherwise) was applied to estimate probabilities that weed intensity in 324 m2 areas was below the threshold. The probabilities could be used to assess the risk that would occur if those areas were not sprayed with herbicides. Because indicator variograms showed a autocorrelation structure of the data the influence of a reduction of sampling points on the reestimation of the probabilities was tested. The coincidence of the probabilities obtained by the reduced data with those estimated with the complete data set was evaluated by correlation (r) and mean relative error (MRE). The loss of information due to the reduction of sampling points to one half was not substantial. Correlations coefficients were high (black bindweed, 0.78; cleavers, 0.82; total weeds, 0.77) with low MRE's. A satisfactory reestimation with one-fourth of the sample points was not possible. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Precision Agriculture Springer Journals

Probability Maps for Risk Asessment in a Patchy Weed Control

Loading next page...
 
/lp/springer_journal/probability-maps-for-risk-asessment-in-a-patchy-weed-control-Rqzauur0FW
Publisher
Kluwer Academic Publishers
Copyright
Copyright © 1999 by Kluwer Academic Publishers
Subject
Life Sciences; Agriculture; Soil Science & Conservation; Remote Sensing/Photogrammetry; Statistics for Engineering, Physics, Computer Science, Chemistry and Earth Sciences; Atmospheric Sciences
ISSN
1385-2256
eISSN
1573-1618
D.O.I.
10.1023/A:1009959808082
Publisher site
See Article on Publisher Site

Abstract

Weeds were monitored during April 1996 along a 36 m×36 m grid within a 21 ha winter wheat field to detected whether black bindweed (Fallopia convolvulus L.), cleavers (Galium aparine L.), which are important weeds in cereals, and total weed densities reached economical thresholds for control. The geostatistical method of block kriging with indicator values (1 if below the threshold and 0 otherwise) was applied to estimate probabilities that weed intensity in 324 m2 areas was below the threshold. The probabilities could be used to assess the risk that would occur if those areas were not sprayed with herbicides. Because indicator variograms showed a autocorrelation structure of the data the influence of a reduction of sampling points on the reestimation of the probabilities was tested. The coincidence of the probabilities obtained by the reduced data with those estimated with the complete data set was evaluated by correlation (r) and mean relative error (MRE). The loss of information due to the reduction of sampling points to one half was not substantial. Correlations coefficients were high (black bindweed, 0.78; cleavers, 0.82; total weeds, 0.77) with low MRE's. A satisfactory reestimation with one-fourth of the sample points was not possible.

Journal

Precision AgricultureSpringer Journals

Published: Oct 6, 2004

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off