Abstract
Abstract Glyphosate‐resistant (GR) alfalfa ( Medicago sativa L.) has been widely adopted in the United States. Exceptional tolerance of GR alfalfa to glyphosate application has been reported as a strength of this technology; however, growers have recently reported potential crop injury under specific environmental conditions. The purpose of this study was to document and characterize the injury and determine best management practices for avoiding injury to GR alfalfa in the Intermountain West. The effects of glyphosate rate and application timing during various seasons were investigated at 24 sites over 5 years, measuring the impact on alfalfa crop height and biomass yield. Summer glyphosate applications did not injure alfalfa. However, spring applications reduced crop height at 76% of sites and biomass yield at 62% of sites. At responsive sites, low (869 g ae ha −1 ) and high (1739 g ae ha −1 ) glyphosate rates reduced yield by 0.53 and 1.06 Mg ha −1 , respectively. Alfalfa treated with high rates in the late spring, when 15–20 cm tall, had mean yield reductions of 16%–17% compared with untreated alfalfa. These results suggest that glyphosate applications made at tall crop heights or high rates on GR alfalfa are more likely to reduce crop height and yield in the Intermountain West compared with earlier applications at lower rates. We recommend that spring applications using low glyphosate rates occur before alfalfa is 10 cm tall to mitigate the risk of injury. If a high glyphosate rate is necessary, then an application should be made before alfalfa is greater than 5 cm tall.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 8
Claim · model-written summary
Summer glyphosate applications did not injure alfalfa.
- Taxon
- alfalfa
Medicago sativae0 - Treatment
- Summer glyphosate applicationse0
- Outcome
- injure alfalfae0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Summer glyphosate applications did not injure alfalfa.”
Claim · model-written summary
Spring glyphosate applications reduced alfalfa height at 76% of sites.
- Taxon
- alfalfaMedicago sativat0
- Treatment
- spring applicationse0
- Outcome
- crop heighte0
- Direction
- reducede0
- Value
- 76% of sitese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“spring applications reduced crop height at 76% of sites”
t0“Glyphosate‐resistant alfalfa”
Claim · model-written summary
Spring glyphosate applications reduced alfalfa biomass yield at 62% of sites.
- Taxon
- alfalfaMedicago sativat0
- Treatment
- spring applicationse0
- Outcome
- biomass yielde0
- Direction
- reducede0
- Value
- 62% of sitese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“spring applications reduced crop height at 76% of sites and biomass yield at 62% of sites”
t0“Glyphosate‐resistant alfalfa”
Claim · model-written summary
At responsive sites, the low glyphosate rate reduced alfalfa yield by 0.53 Mg ha −1.
- Taxon
- alfalfaMedicago sativat0
- Treatment
- low (869 g ae ha −1 )e0
- Outcome
- yielde0
- Direction
- reducede0
- Value
- 0.53e0
- Qualifier
- At responsive sitese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At responsive sites, low (869 g ae ha −1 ) and high (1739 g ae ha −1 ) glyphosate rates reduced yield by 0.53 and 1.06 Mg ha −1 , respectively.”
t0“Glyphosate‐resistant alfalfa”
Claim · model-written summary
At responsive sites, the high glyphosate rate reduced alfalfa yield by 1.06 Mg ha −1.
- Taxon
- alfalfaMedicago sativat0
- Treatment
- high (1739 g ae ha −1 )e0
- Outcome
- yielde0
- Direction
- reducede0
- Value
- 1.06 Mg ha −1e0
- Qualifier
- At responsive sitese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At responsive sites, low (869 g ae ha −1 ) and high (1739 g ae ha −1 ) glyphosate rates reduced yield by 0.53 and 1.06 Mg ha −1 , respectively.”
t0“Glyphosate‐resistant alfalfa”
Claim · model-written summary
High glyphosate rates in late spring at 15–20 cm crop height reduced mean alfalfa yield by 16%–17% versus untreated alfalfa.
- Taxon
- AlfalfaMedicago sativae0
- Treatment
- high rates in the late springe0
- Outcome
- mean yield reductionse0
- Direction
- reductionse0
- Value
- 16%–17%e0
- Qualifier
- when 15–20 cm talle0
- Comparator
- untreated alfalfae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Alfalfa treated with high rates in the late spring, when 15–20 cm tall, had mean yield reductions of 16%–17% compared with untreated alfalfa.”
Claim · model-written summary
The authors recommend spring applications at low glyphosate rates before alfalfa is 10 cm tall.
- Taxon
- alfalfaMedicago sativae0
- Outcome
- spring applications using low glyphosate rates occur before alfalfa is 10 cm talle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We recommend that spring applications using low glyphosate rates occur before alfalfa is 10 cm tall to mitigate the risk of injury.”
Claim · model-written summary
If a high glyphosate rate is needed, the authors recommend applying it before alfalfa exceeds 5 cm.
- Taxon
- alfalfaMedicago sativae0
- Outcome
- an application should be made before alfalfa is greater than 5 cm talle0
- Qualifier
- If a high glyphosate rate is necessarye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“If a high glyphosate rate is necessary, then an application should be made before alfalfa is greater than 5 cm tall.”
The same questions in other papers
glyphosate · organism · Medicago sativa (alfalfa)Results differ
4 papers in the same direction as this paper · 7 in the opposite direction
- positive
- positive
- positive
8 papers more in this group
See all 12 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.