Abstract
SUMMARY Onion thrips ( Thrips tabaci ) is the major pest of onions in the Sudan. In the Gezira Scheme onions are normally transplanted between October and January when the thrips population is very low. Later, thrips commence to breed. Early transplanted onions were well established before infestations became severe and, without the need for insecticidal control, produced significantly higher yields. Onions transplanted later, when thrips began to multiply, produced lower yields. Depending on the duration and intensity of infestation three to five sprays applied at fortnightly intervals were required to control thrips on the late transplanted crop. The effect of spray frequency on the development and yield of onions was investigated and the response found to be solely due to the extent of thrips control achieved. The toxicant itself had no effect on growth. Although the leaves were unaffected by the various treatments, spraying when most thrips were present increased fresh and dry leaf weights, bulb weight and, in the Hudeiba cultivar, the proportion of flowering plants. With the late‐transplanted crop, light infestations led to yield losses of at least 39% whilst severe thrips attacks reduced the crop by 57%.
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Claims 9
Claim · model-written summary
Early transplanted onions produced significantly higher yields before severe thrips infestation.
- Taxon
- onions
Allium cepae0 - Treatment
- Early transplantede0
- Outcome
- yieldse0
- Direction
- highere0
Not reportedInteractorComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Early transplanted onions were well established before infestations became severe and, without the need for insecticidal control, produced significantly higher yields.”
Claim · model-written summary
Later transplanted onions produced lower yields.
- Taxon
- OnionsAllium cepae0
- Treatment
- transplanted latere0
- Outcome
- yieldse0
- Direction
- lowere0
ThripsNot reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Onions transplanted later, when thrips began to multiply, produced lower yields.”
Claim · model-written summary
Three to five fortnightly sprays were needed to control thrips on late transplanted onions.
Not reportedTaxon
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Depending on the duration and intensity of infestation three to five sprays applied at fortnightly intervals were required to control thrips on the late transplanted crop.”
Claim · model-written summary
Onion development and yield response to spraying depended on thrips control.
- Taxon
- onionsAllium cepae0
- Treatment
- spray frequencye0
- Outcome
- development and yielde0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The effect of spray frequency on the development and yield of onions was investigated and the response found to be solely due to the extent of thrips control achieved.”
Claim · model-written summary
The toxicant itself had no effect on onion growth.
Not reportedTaxonComparator
Verbatim
e0“The toxicant itself had no effect on growth.”
Claim · model-written summary
Spraying at peak thrips abundance increased fresh and dry leaf weights and bulb weight.
- Treatment
- spraying when most thrips were presente0
- Outcome
- fresh and dry leaf weights, bulb weighte0
- Direction
- increasede0
Not reportedTaxonComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“spraying when most thrips were present increased fresh and dry leaf weights, bulb weight and, in the Hudeiba cultivar, the proportion of flowering plants.”
Claim · model-written summary
Peak-abundance spraying increased the flowering proportion in Hudeiba.
- Material
- Hudeibae0
- Treatment
- spraying when most thrips were presente0
- Outcome
- proportion of flowering plantse0
- Direction
- increasede0
Not reportedTaxonComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“spraying when most thrips were present increased fresh and dry leaf weights, bulb weight and, in the Hudeiba cultivar, the proportion of flowering plants.”
Claim · model-written summary
Light thrips infestation caused at least 39% yield loss.
Not reportedTaxonInteractorComparator
Verbatim
e0“light infestations led to yield losses of at least 39%”
Claim · model-written summary
Severe thrips infestation reduced crop yield by 57%.
Not reportedTaxonComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“severe thrips attacks reduced the crop by 57%”
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See all 8 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.