Abstract
Summary The effects of three weeding systems with and without top‐dressed nitrogen were examined in 40 experiments on bread wheat and durum wheat planted by farmers in the Chaouia (semi‐arid area of Morocco) in 1984–1985 and 1985–1986 growing seasons. In both years, hand‐weeding to simulate collection of forage reduced weed numbers by 30% and removed 63% of the weed dry weight. Treatment with 2, 4‐D removed 66% of the weeds and reduced weed dry weight by 82%, in 1985–1986. Hand‐weeding for forage produced 427 kg ha −1 weed dry matter in both years, but wheat grain yields were 179 kg ha −1 lower than with 2.4‐D treatments. Over both years, the cost of each kg weed forage was 0·43 kg grain yield loss. Without weeding grain yields were 130 kg ha −1 lower than 2, 4‐D treatments. Weed control with 2,4‐D increased wheat grain yields over both non‐weeded and hand‐weeded treatments by an average of 154 kg ha −1 . Overall, there were no significant effects of nitrogen on wheat or weed yields nor interactions between top‐dressed nitrogen and weeding systems. A total of 157 weed species belonging to 29 botanical families were identified on the 40 experimental sites over both years; 89% were dicotyledons. Papaver rhoeas L. (common poppy), 2, 4‐D susceptible plant, was the most annual weed in wheat fields in Chaouia.
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Claims 13
Claim · model-written summary
weed numbers changed under hand‐weeding
- Taxon
- wheat
Triticum aestivumt0 - Treatment
- hand‐weedinge0
- Outcome
- weed numberse0
- Direction
- reducede0
- Value
- 30%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“hand‐weeding to simulate collection of forage reduced weed numbers by 30%”
t0“wheat”
Claim · model-written summary
weed dry weight changed under hand‐weeding
- Taxon
- wheatTriticum aestivumt0
- Treatment
- weed dry weighte0
- Outcome
- weed dry weighte0
- Direction
- removede0
- Value
- 63%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“removed 63% of the weed dry weight”
t0“wheat”
Claim · model-written summary
weeds changed under 2, 4‐D
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Treatment with 2, 4‐D removed 66% of the weeds”
t0“wheat”
Claim · model-written summary
weed dry weight changed under 2, 4‐D
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Treatment with 2, 4‐D removed 66% of the weeds and reduced weed dry weight by 82%”
t0“wheat”
Claim · model-written summary
weed dry matter changed under Hand‐weeding
- Taxon
- wheatTriticum aestivumt0
- Treatment
- Hand‐weedinge0
- Outcome
- weed dry mattere0
- Direction
- producede0
- Value
- 427 kg ha −1e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Hand‐weeding for forage produced 427 kg ha −1 weed dry matter”
t0“wheat”
Claim · model-written summary
wheat grain yields changed under Hand‐weeding
- Taxon
- wheatTriticum aestivume0
- Treatment
- 2.4‐D treatmentse0
- Outcome
- wheat grain yieldse0
- Direction
- lowere0
- Value
- 179 kg ha −1e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“wheat grain yields were 179 kg ha −1 lower than with 2.4‐D treatments”
Claim · model-written summary
grain yield loss changed under Hand‐weeding
- Taxon
- wheatTriticum aestivumt0
- Treatment
- weed foragee0
- Outcome
- grain yield losse0
- Direction
- losse0
- Value
- 0·43 kge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the cost of each kg weed forage was 0·43 kg grain yield loss”
t0“wheat”
Claim · model-written summary
grain yields changed under Without weeding
- Taxon
- wheatTriticum aestivumt0
- Treatment
- Without weedinge0
- Outcome
- grain yieldse0
- Direction
- lowere0
- Value
- 130 kg ha −1e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Without weeding grain yields were 130 kg ha −1 lower than 2, 4‐D treatments”
t0“wheat”
Claim · model-written summary
wheat grain yields changed under 2,4‐D
- Taxon
- wheatTriticum aestivume0
- Treatment
- 2,4‐De0
- Outcome
- wheat grain yieldse0
- Direction
- increasede0
- Value
- 154 kg ha −1e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Weed control with 2,4‐D increased wheat grain yields over both non‐weeded and hand‐weeded treatments by an average of 154 kg ha −1”
Claim · model-written summary
wheat or weed yields changed under nitrogen
- Taxon
- wheatTriticum aestivume0
- Treatment
- nitrogene0
- Outcome
- wheat or weed yieldse0
- Direction
- no significant effectse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“there were no significant effects of nitrogen on wheat or weed yields”
Claim · model-written summary
interactions changed under top‐dressed nitrogen
- Taxon
- wheatTriticum aestivumt0
- Treatment
- top‐dressed nitrogene0
- Outcome
- interactionse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“nor interactions between top‐dressed nitrogen and weeding systems”
t0“wheat”
Claim · model-written summary
The sites contained 157 weed species in 29 families
- Taxon
- wheatTriticum aestivumt0
- Outcome
- weed speciese0
- Value
- 157 weed speciese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A total of 157 weed species belonging to 29 botanical families were identified on the 40 experimental sites over both years; 89% were dicotyledons.”
t0“wheat”
Claim · model-written summary
Papaver rhoeas was the most common annual weed
- Taxon
- wheatTriticum aestivume0
- Interactor
- Papaver rhoeas L.
Papaver rhoease0weed - Outcome
- most annual weede0
- Setting
- Chaouiae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Papaver rhoeas L. (common poppy), 2, 4‐D susceptible plant, was the most annual weed in wheat fields in Chaouia.”
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See all 563 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.