Abstract
Plant growth regulators (PGRs) alter tiller growth in cereals. This response may be dependent on daylength (DL). Standard height (HE) and dwarf oat cultivars were grown at 14‐ and 18‐h DLs. Foliage was sprayed with chlormequat chloride (CCC) and ethephon at early growth stages to evaluate PGR effects on the growth of the main shoot and tillers. Two successive experiments with 10 replicates were arranged in two growth chambers (14‐h and 18‐h DL) at the University of Minnesota. Preanthesis main shoot and tiller HEs and dry weights (DWs) were measured. In Exp. 1, the numbers of leaves and green leaves were counted. Relative growth rate (RGR), relative elongation rate (RER), and shoot DW:HE ratio were measured. Plant growth regulators retarded growth of the main shoot in conventional oat cultivars without stimulating growth of T1 and T2 tillers. Response of the dwarf cultivar to PGRs was modest. Only ethephon enhanced T1 tiller growth at 18‐h DL. However, PGR‐treated plants had up to five more green leaves per plant at preanthesis due to stimulated leaf emergence on T3 and T4 tillers especially at the 18‐h DL. In Exp. 1, PGR treatments reduced the DW to HE ratio, that is, shortened rather than strengthened the stem. In Exp. 2, measurements were made more frequently and ethephon first increased this ratio followed by a decrease. Thus, even though long‐day conditions somewhat enhanced DW accumulation and stem elongation, few marked differences in oat response to PGR treatments were noted when comparing short‐ and long‐day conditions.
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
Growth regulators retarded main shoot growth in conventional oat cultivars.
- Taxon
- oat
Avena sativae0 - Organ / stage
- main shoote0
- Treatment
- Plant growth regulatorse0
- Outcome
- growthe0
- Direction
- retardede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plant growth regulators retarded growth of the main shoot in conventional oat cultivars without stimulating growth of T1 and T2 tillers.”
Claim · model-written summary
Growth regulators did not stimulate T1 and T2 tiller growth.
Not reportedTaxonTreatmentComparator
Verbatim
e0“without stimulating growth of T1 and T2 tillers”
Claim · model-written summary
The dwarf oat cultivar showed only a modest response to growth regulators.
Not reportedTaxon
Verbatim
e0“Response of the dwarf cultivar to PGRs was modest.”
Claim · model-written summary
Ethephon enhanced T1 tiller growth under an 18-hour daylength.
Not reportedTaxonComparator
Verbatim
e0“Only ethephon enhanced T1 tiller growth at 18‐h DL.”
Claim · model-written summary
Growth regulator treated oats had up to five more green leaves by preanthesis through T3 and T4 leaf emergence.
- Organ / stage
- preanthesise0
- Treatment
- PGR‐treatede0
- Outcome
- green leaves per plante0
- Direction
- moree0
- Value
- up to fivee0
Not reportedTaxonComparator
Verbatim
e0“PGR‐treated plants had up to five more green leaves per plant at preanthesis due to stimulated leaf emergence on T3 and T4 tillers especially at the 18‐h DL.”
Claim · model-written summary
In experiment 1 growth regulators reduced the dry weight to height ratio.
Not reportedTaxonComparator
Verbatim
e0“In Exp. 1, PGR treatments reduced the DW to HE ratio, that is, shortened rather than strengthened the stem.”
Claim · model-written summary
In experiment 2 ethephon first raised and then lowered the dry weight to height ratio.
Not reportedTaxonComparator
Verbatim
e0“In Exp. 2, measurements were made more frequently and ethephon first increased this ratio followed by a decrease.”
Claim · model-written summary
Long days somewhat enhanced dry weight accumulation and stem elongation.
Not reportedTaxonComparator
Verbatim
e0“long‐day conditions somewhat enhanced DW accumulation and stem elongation”
The same questions in other papers
class · growth · Avena sativa (oats)Positive and negative results
3 papers in the same direction as this paper · 8 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.