Abstract
Abstract Possibilities to improve maize harvest index and nutrient utilization efficiency by application of plant growth regulators were investigated. In container experiments, the effects of different growth regulators on the development of the maize ( Zea mays L.) cultivars Pioneer 3906 and Fabregas were tested. Paclobutrazol (PAC) and chlorocholine chloride (CCC), two inhibitors of gibberellin biosynthesis, as well as gibberellic acid (GA 3 ) were applied at growth stage V5. Three weeks after application of PAC, shoot growth of both maize cultivars was strongly affected with a significant decrease in plant height in the PAC treatment by 44% and 36% for Pioneer 3906 and Fabregas, respectively. The growth‐retarded plants had higher leaf areas and reduced transpiration rates. The higher shoot growth after GA 3 application was accompanied by a reduction in leaf area and an increase in transpiration rate during 1 week before anthesis. CCC treatment showed no significant effects on plant height, leaf area and transpiration rate. The PAC‐treated cultivar Pioneer 3906 produced several cobs per plant, which were mainly barren at maturity. However, PAC application to Fabregas resulted in just one cob per plant with good kernel development and a grain yield, which was not significantly reduced in comparison with the control. With this similar grain yield in combination with a straw yield decrease of 32%, the harvest index was significantly improved by 12%. In addition, with PAC‐treated Fabregas plants, a 19% increased water use efficiency of the grain (WUE grain ) during the critical period of kernel setting was achieved. In this maize cultivar, CCC application also improved harvest index by 5%, but no effect on WUE grain occurred. GA 3 treatment decreased harvest index of both maize cultivars, and it either reduced WUE grain (Pioneer 3906) or showed no effect (Fabregas). Utilization efficiencies of N, P and K were not increased with growth regulator application, even in the PAC‐treated Fabregas plants with a significantly improved allocation of assimilates to the grain, mirrored by the higher harvest index. The results indicate that fertilizer applications must be adjusted to the reduced demand of growth‐retarded plants, most likely leading to higher nutrient utilization efficiencies.
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Claims 18
Claim · model-written summary
PAC reduced Pioneer 3906 height by 44%.
Zea maysNot reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“significant decrease in plant height in the PAC treatment by 44% and 36% for Pioneer 3906 and Fabregas, respectively”
e1“maize ( Zea mays L.)”
Claim · model-written summary
PAC reduced Fabregas height by 36%.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“significant decrease in plant height in the PAC treatment by 44% and 36% for Pioneer 3906 and Fabregas, respectively”
e1“maize ( Zea mays L.)”
Claim · model-written summary
PAC-treated plants had greater leaf area.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The growth‐retarded plants had higher leaf areas and reduced transpiration rates”
e1“maize ( Zea mays L.)”
e2“PAC‐treated cultivar Pioneer 3906”
Claim · model-written summary
PAC-treated plants had lower transpiration.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The growth‐retarded plants had higher leaf areas and reduced transpiration rates”
e1“maize ( Zea mays L.)”
e2“PAC‐treated cultivar Pioneer 3906”
Claim · model-written summary
GA 3 increased shoot growth.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“higher shoot growth after GA 3 application”
e1“maize ( Zea mays L.)”
Claim · model-written summary
GA 3 reduced leaf area.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“GA 3 application was accompanied by a reduction in leaf area”
e1“maize ( Zea mays L.)”
Claim · model-written summary
GA 3 increased transpiration before anthesis.
- Treatment
- GA 3 applicatione1
- Outcome
- transpiration ratee0
- Direction
- increasee0
- Qualifier
- during 1 week before anthesise0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“an increase in transpiration rate during 1 week before anthesis”
e1“GA 3 application”
e2“maize ( Zea mays L.)”
Claim · model-written summary
CCC had no significant effect on height, leaf area or transpiration.
- Treatment
- CCC treatmente0
- Outcome
- plant height, leaf area and transpiration ratee0
- Direction
- no significant effectse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“CCC treatment showed no significant effects on plant height, leaf area and transpiration rate”
e1“maize ( Zea mays L.)”
Claim · model-written summary
PAC-treated Pioneer 3906 had several mostly barren cobs.
- Material
- Pioneer 3906e0
- Treatment
- PACe0
- Outcome
- several cobs per plant, which were mainly barren at maturitye0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“PAC‐treated cultivar Pioneer 3906 produced several cobs per plant, which were mainly barren at maturity”
e1“maize ( Zea mays L.)”
Claim · model-written summary
PAC-treated Fabregas had one cob with good kernel development.
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“PAC application to Fabregas resulted in just one cob per plant with good kernel development”
e1“maize ( Zea mays L.)”
Claim · model-written summary
PAC did not significantly reduce Fabregas grain yield.
- Material
- Fabregase1
- Treatment
- PACe1
- Outcome
- grain yielde0
- Direction
- not significantly reducede0
- Comparator
- the controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“grain yield, which was not significantly reduced in comparison with the control”
e1“PAC application to Fabregas”
e2“maize ( Zea mays L.)”
Claim · model-written summary
PAC decreased Fabregas straw yield by 32%.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“straw yield decrease of 32%”
e1“with PAC‐treated Fabregas plants”
e2“maize ( Zea mays L.)”
Claim · model-written summary
PAC improved Fabregas harvest index by 12%.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“harvest index was significantly improved by 12%”
e1“with PAC‐treated Fabregas plants”
e2“maize ( Zea mays L.)”
Claim · model-written summary
PAC increased Fabregas grain water-use efficiency by 19% during kernel setting.
- Material
- Fabregase0
- Treatment
- PACe0
- Outcome
- water use efficiency of the graine0
- Direction
- increasede0
- Value
- 19%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“PAC‐treated Fabregas plants, a 19% increased water use efficiency of the grain (WUE grain ) during the critical period of kernel setting was achieved”
e1“maize ( Zea mays L.)”
Claim · model-written summary
CCC did not affect Fabregas grain water-use efficiency.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“no effect on WUE grain occurred”
e1“CCC application”
e2“In this maize cultivar”
Claim · model-written summary
GA 3 reduced harvest index in both maize cultivars.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“GA 3 treatment decreased harvest index of both maize cultivars”
Claim · model-written summary
GA 3 reduced Pioneer 3906 grain water-use efficiency.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“it either reduced WUE grain (Pioneer 3906)”
e1“GA 3 treatment decreased harvest index of both maize cultivars”
Claim · model-written summary
Growth regulator application did not increase N, P or K utilization efficiency.
- Treatment
- growth regulator applicatione0
- Outcome
- Utilization efficiencies of N, P and Ke0
- Direction
- not increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Utilization efficiencies of N, P and K were not increased with growth regulator application”
e1“In this maize cultivar”
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See all 5 papers →8 of 9 groups shown: named compounds and organisms first, then groups whose results differ (checked claim by claim), then those with positive and negative results, then the smaller groups.
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.