Abstract
Soybean (Glycine max L. MERR.) has expanded to become one of the most traded agriculture products worldwide in recent decades. Europe is one of the primary importing regions; however, the dependence on soybean imports has been critically assessed by the public. To reduce the dependency on soybean imports, increased local soybean production should be favoured. In addition to environmental conditions, weeds are a major limiting factor for soybean yield under German climate conditions. Weeds can be successfully controlled with herbicides, although crop injury frequently occurs after application. Sensor-based screening would be helpful for a rapid evaluation of cultivar tolerance to herbicide application. Alternatively, mechanical weed control strategies can be applied. Since soybean production is currently introduced to the regional crop production, weed control efficiency of conventional mechanical tools (e.g., hoeing and harrowing) have to be evaluated. By using automatic guiding systems intra-row elements could be utilised to increase the weed control efficiency of mechanical hoeing. Other than that, agronomical practices such as the tillage system or cover crops influences the occurrence of weeds. The most common practise worldwide for soybean cultivation is the no-tillage system, which has not yet been investigated under local conditions. Therefore, different weed control strategies in soybean production were investigated according to the following major objectives of this thesis: - Detection of crop injury by herbicides using a chlorophyll fluorescence imaging sensor for different soybean cultivars. - Evaluation of the conventional mechanical strategies of hoeing and harrowing in soybean. - Examination of the weed control efficiency in inter- and intra-row areas using RTK-GNSS precision steering and an optical camera guiding system for mechanical weed control in soybean. - Evaluation of the efficiency of tillage, reduced tillage and no- tillage cultivation systems and the influence of cover crops on weed suppression in local soybean production. The Imaging-PAM-sensor based on chlorophyll fluorescence imaging was utilised to investigate the response of different soybean cultivars to the application of herbicides. The measurements indicated significant differences with respect to injury to the cultivars after herbicide application. Herbicides containing the active ingredient metribuzin resulted in significant differences in the level of crop injury depending on the cultivar. The active ingredients dimethenamid and clomazone resulted in less injury, independent of the cultivar. The PAM-sensor was able to detect stress symptoms 3 to 7 days before visual symptoms appeared. An investigation of hoeing and harrowing, which are conventional mechanical techniques for weed control, showed 78% and 72% weed control efficiency, respectively. In further experiments, the results of precision steering systems using RTK-GNSS and an optical camera guiding system additionally equipped with intra-row elements (e.g., finger weeders) were compared with the results of conventional hoeing. Mechanical weed control using automatic steering technology and an intra-row element (finger weeder) reduced the weed density by 89% compared with 68% in the conventional hoeing system. With respect to crop yields, statistical benefits of precision steering were not observed. However, the driving speed could be increased from 4 km h−1 in the conventional hoeing system to 10 km h−1 using the automatic steering systems. In an additional experiment, two cover crops species, rye (Secale cereale L.) and barley (Hordeum vulgare L.), were grown for preventive weed control in soybean production. The cover crops were transformed into a mulch layer using a roller-crimper immediately before soybean was sown using a no-tillage technique. Conventional tillage was performed to compare the systems with respect to their weed control efficiency, crop development and soybean yield. The results showed that the no-tillage system had a greater effect on suppressing summer annual weed species (Chenopodium album (L.), Echinochloa crus-galli (L.) P. Beauv. and Amaranthus retroflexus (L.)) than the tillage systems. Conventional tillage and reduced tillage showed increased suppression of the weed species Matricaria inodora (L.), Stellaria media (L.) Vill. and Sonchus arvensis (L.), which were present in the no-tillage system. However, in the conventional tillage and reduced tillage systems, an additional weed control treatment was necessary to suppress the summer annual weeds and ensure high yields. The cover crop rye resulted in weed control similar to that of barley in the no-tillage system. Despite the low weed density, the no-tillage system with a rolled cover crop showed a yield reduced of 47%, whereas the yield of the reduced tillage system was decrease by 23% compared with the conventional tillage system.
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Claims 16
Claim · model-written summary
Soybean cultivars differed significantly in injury after herbicide application.
- Taxon
- Soybean
Glycine maxe0 - Treatment
- herbicide applicatione1
- Outcome
- injury to the cultivarse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean (Glycine max L. MERR.)”
e1“The measurements indicated significant differences with respect to injury to the cultivars after herbicide application”
Claim · model-written summary
Metribuzin caused cultivar dependent differences in crop injury.
- Taxon
- SoybeanGlycine maxe0
- Treatment
- metribuzine1
- Outcome
- crop injurye1
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean (Glycine max L. MERR.)”
e1“Herbicides containing the active ingredient metribuzin resulted in significant differences in the level of crop injury depending on the cultivar”
Claim · model-written summary
Dimethenamid caused less injury across cultivars.
- Taxon
- SoybeanGlycine maxe0
- Treatment
- dimethenamide1
- Outcome
- injurye1
- Direction
- lesse1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean (Glycine max L. MERR.)”
e1“The active ingredients dimethenamid and clomazone resulted in less injury, independent of the cultivar”
Claim · model-written summary
Clomazone caused less injury across cultivars.
- Taxon
- SoybeanGlycine maxe0
- Treatment
- clomazonee1
- Outcome
- injurye1
- Direction
- lesse1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean (Glycine max L. MERR.)”
e1“The active ingredients dimethenamid and clomazone resulted in less injury, independent of the cultivar”
Claim · model-written summary
The PAM sensor detected stress three to seven days before visual symptoms.
- Taxon
- SoybeanGlycine maxe0
- Outcome
- stress symptomse1
- Value
- 3 to 7 dayse1
- Comparator
- visual symptomse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean (Glycine max L. MERR.)”
e1“The PAM-sensor was able to detect stress symptoms 3 to 7 days before visual symptoms appeared”
Claim · model-written summary
Hoeing achieved 78% weed control efficiency.
- Taxon
- SoybeanGlycine maxe0
- Treatment
- hoeinge1
- Outcome
- weed control efficiencye1
- Value
- 78%e1
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean (Glycine max L. MERR.)”
e1“An investigation of hoeing and harrowing, which are conventional mechanical techniques for weed control, showed 78% and 72% weed control efficiency, respectively”
Claim · model-written summary
Harrowing achieved 72% weed control efficiency.
- Taxon
- SoybeanGlycine maxe0
- Treatment
- harrowinge1
- Outcome
- weed control efficiencye1
- Value
- 72%e1
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean (Glycine max L. MERR.)”
e1“An investigation of hoeing and harrowing, which are conventional mechanical techniques for weed control, showed 78% and 72% weed control efficiency, respectively”
Claim · model-written summary
Automatic steering with a finger weeder reduced weed density by 89%.
- Taxon
- SoybeanGlycine maxe0
- Treatment
- automatic steering technology and an intra-row element (finger weeder)e1
- Outcome
- weed densitye1
- Direction
- reducede1
- Value
- 89%e1
- Qualifier
- 68%e1
- Comparator
- conventional hoeing systeme1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean (Glycine max L. MERR.)”
e1“Mechanical weed control using automatic steering technology and an intra-row element (finger weeder) reduced the weed density by 89% compared with 68% in the conventional hoeing system”
Claim · model-written summary
Precision steering did not yield a statistical crop yield benefit.
- Taxon
- SoybeanGlycine maxe0
- Treatment
- precision steeringe1
- Outcome
- crop yieldse1
- Direction
- not observede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean (Glycine max L. MERR.)”
e1“With respect to crop yields, statistical benefits of precision steering were not observed”
Claim · model-written summary
Automatic steering increased driving speed from 4 to 10 km h−1.
- Taxon
- SoybeanGlycine maxe0
- Outcome
- driving speede1
- Direction
- increasede1
- Value
- 10 km h−1e1
- Qualifier
- 4 km h−1e1
- Comparator
- conventional hoeing systeme1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean (Glycine max L. MERR.)”
e1“the driving speed could be increased from 4 km h−1 in the conventional hoeing system to 10 km h−1 using the automatic steering systems”
Claim · model-written summary
No tillage suppressed summer annual weeds more than tilled systems.
- Taxon
- SoybeanGlycine maxe0
- Treatment
- no-tillage systeme1
- Outcome
- suppressing summer annual weed speciese1
- Direction
- greatere1
- Comparator
- tillage systemse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean (Glycine max L. MERR.)”
e1“the no-tillage system had a greater effect on suppressing summer annual weed species (Chenopodium album (L.), Echinochloa crus-galli (L.) P. Beauv. and Amaranthus retroflexus (L.)) than the tillage systems”
Claim · model-written summary
Conventional and reduced tillage suppressed Matricaria, Stellaria and Sonchus more than no tillage.
- Taxon
- SoybeanGlycine maxe0
- Treatment
- Conventional tillage and reduced tillagee1
- Outcome
- suppression of the weed speciese1
- Direction
- increasede1
- Comparator
- no-tillage systeme1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean (Glycine max L. MERR.)”
e1“Conventional tillage and reduced tillage showed increased suppression of the weed species Matricaria inodora (L.), Stellaria media (L.) Vill. and Sonchus arvensis (L.), which were present in the no-tillage system”
Claim · model-written summary
Additional weed control was needed under conventional and reduced tillage to ensure high yield.
- Taxon
- SoybeanGlycine maxe0
- Outcome
- an additional weed control treatment was necessarye1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean (Glycine max L. MERR.)”
e1“in the conventional tillage and reduced tillage systems, an additional weed control treatment was necessary to suppress the summer annual weeds and ensure high yields”
Claim · model-written summary
Rye and barley cover crops gave similar weed control in no tillage.
- Taxon
- SoybeanGlycine maxe0
- Material
- ryee1
- Outcome
- weed controle1
- Comparator
- barleye1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean (Glycine max L. MERR.)”
e1“The cover crop rye resulted in weed control similar to that of barley in the no-tillage system”
Claim · model-written summary
Rolled cover crop no tillage reduced yield by 47% against conventional tillage.
- Taxon
- SoybeanGlycine maxe0
- Treatment
- no-tillage system with a rolled cover crope1
- Outcome
- yielde1
- Direction
- reducede1
- Value
- 47%e1
- Comparator
- conventional tillage systeme1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean (Glycine max L. MERR.)”
e1“the no-tillage system with a rolled cover crop showed a yield reduced of 47%, whereas the yield of the reduced tillage system was decrease by 23% compared with the conventional tillage system”
Claim · model-written summary
Reduced tillage reduced yield by 23% against conventional tillage.
- Taxon
- SoybeanGlycine maxe0
- Treatment
- reduced tillage systeme1
- Outcome
- yielde1
- Direction
- decreasee1
- Value
- 23%e1
- Comparator
- conventional tillage systeme1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soybean (Glycine max L. MERR.)”
e1“the yield of the reduced tillage system was decrease by 23% compared with the conventional tillage system”
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See all 390 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.