Abstract
Conflicting results have been reported on the effects of spacing and emergence variability on grain yield in maize ( Zea mays L.). Effects of spacing and emergence variability on maize grain yield are the net result of the responses of all plants within the stand. The objective of this study was to quantify effects of spacing and emergence variability on crop yield in terms of increased or decreased crowding stress on resource capture (i.e., dry matter accumulation) and resource utilization (i.e., dry matter partitioning) of the individual plants within the crop canopy. Results of previously reported studies were analyzed in terms of plant dry matter accumulation, leaf area, plant growth rate during the critical period for kernel set bracketed by silking (PGR s ), grain yield, and harvest index, that is, the proportion of dry matter partitioned to the grain at maturity. Results show that a moderate increase in plant‐spacing variability does not influence maize grain yield at the canopy level because reductions in grain yield of plants that experience enhanced crowding stress is compensated, in part, by increased yield of plants that experience reduced crowding stress; crowding stress affected dry matter accumulation but did not affect harvest index. In contrast, plant‐emergence variability reduced grain yield at the canopy level because the reduction in grain yield was attributable, in part, to a reduction in harvest index of plants with PGR s less than the threshold for kernel set. Hence, plants can compensate for factors that influence resource capture, but cannot compensate for a reduction in factors that influence resource utilization.
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 9
Claim · model-written summary
Moderate plant-spacing variability did not change canopy-level maize grain yield.
- Treatment
- moderate increase in plant‐spacing variabilitye0
- Outcome
- maize grain yield at the canopy levele0
- Direction
- does not influencee0
Zea maysNot reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a moderate increase in plant‐spacing variability does not influence maize grain yield at the canopy level”
Claim · model-written summary
Enhanced crowding stress reduced grain yield of individual maize plants.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“reductions in grain yield of plants that experience enhanced crowding stress”
e1“maize grain yield are the net result”
Claim · model-written summary
Reduced crowding stress increased yield of individual maize plants.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased yield of plants that experience reduced crowding stress”
e1“maize grain yield are the net result”
Claim · model-written summary
Crowding stress affected dry matter accumulation.
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“crowding stress affected dry matter accumulation”
e1“maize grain yield are the net result”
Claim · model-written summary
Crowding stress did not affect harvest index.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“crowding stress affected dry matter accumulation but did not affect harvest index”
e1“maize grain yield are the net result”
Claim · model-written summary
Plant-emergence variability reduced canopy-level maize grain yield.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“plant‐emergence variability reduced grain yield at the canopy level”
e1“maize grain yield are the net result”
Claim · model-written summary
Lower harvest index in plants below the kernel-set growth threshold partly explained the yield reduction under emergence variability.
- Outcome
- reduction in grain yielde0
- Qualifier
- reduction in harvest index of plants with PGR s less than the threshold for kernel sete0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“reduction in grain yield was attributable, in part, to a reduction in harvest index of plants with PGR s less than the threshold for kernel set”
e1“maize grain yield are the net result”
Claim · model-written summary
The authors infer that maize plants compensate for factors influencing resource capture.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“plants can compensate for factors that influence resource capture”
e1“maize grain yield are the net result”
Claim · model-written summary
The authors infer that maize plants cannot compensate for reduced resource utilization.
- Outcome
- cannot compensate for a reduction in factors that influence resource utilizatione0
- Qualifier
- resource utilizatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“cannot compensate for a reduction in factors that influence resource utilization”
e1“maize grain yield are the net result”
The same questions in other papers
competition · yield · Zea mays (maize)Results differ
6 papers in the same direction as this paper · 31 in the opposite direction
- no effect
- no effect
- negative
34 papers more in this group
See all 38 papers →density · yield · Zea mays (maize)Positive and negative results
138 papers in the same direction as this paper · 519 in the opposite direction
- positive
- positive
- positive
654 papers more in this group
See all 658 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.