Abstract
Context Unmanned aerial seeding (UAS) of rice (Oryza sativa) has inherent advantages, but may not achieve a high and stable yield when extensive stubble is returned. Aims This study aimed to determine the optimal planting density for achieving high yield and lodging resistance in UAS rice. Methods The experiment evaluated yield and lodging of two rice varieties (conventional japonica and hybrid indica–japonica) at four planting densities 105 (D1), 150 (D2), 195 (D3), and 240 (D4) seedlings m−2 for conventional japonica; 45 (D1), 82.5 (D2), 120 (D3), and 157.5 (D4) seedlings m−2 for hybrid indica–japonica). Key results Our results showed that yield initially increased and then decreased with increasing density, and the highest yield was obtained under treatment D3. Increasing planting density increased the proportion of main stem panicles and the effective panicles, but decreased the number of grains per panicle, seed setting rate, and 1000-grain weight. The population growth rate was lower in seeding-jointing and heading-maturity stages for treatments D1 and D2, higher in seeding-jointing stage for treatment D4 but insufficient in subsequent stages, while treatment D3 had higher population growth rate throughout the whole growth stage, especially in heading-maturity stages, ultimately achieving high yield. Densification led to a reduction in plant height and ear length, as well as slender internodes and thinner base wall. Conclusions A planting density of 195 seedlings m−2 was optimal for conventional japonica rice, and 120 seedlings m−2 for indica–japonica. Implications Achieving high yield of UAS rice can be facilitated by increasing planting density, but may compromise lodging resistance.
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Claims 11
Claim · model-written summary
Rice yield rose and then fell as planting density increased, peaking at D3.
- Taxon
- rice
Oryza sativat0 - Treatment
- increasing densitye0
- Outcome
- yielde0
- Direction
- initially increased and then decreasede0
Not reportedMaterialComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“yield initially increased and then decreased with increasing density, and the highest yield was obtained under treatment D3”
t0“rice (Oryza sativa)”
Claim · model-written summary
Higher planting density increased the proportion of main stem panicles and effective panicles.
- Taxon
- riceOryza sativat0
- Treatment
- Increasing planting densitye0
- Outcome
- proportion of main stem panicles and the effective paniclese0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Increasing planting density increased the proportion of main stem panicles and the effective panicles”
t0“rice (Oryza sativa)”
Claim · model-written summary
Higher planting density reduced grains per panicle, seed setting rate, and 1000-grain weight.
- Taxon
- riceOryza sativat0
- Treatment
- Increasing planting densitye0
- Outcome
- number of grains per panicle, seed setting rate, and 1000-grain weighte0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Increasing planting density increased the proportion of main stem panicles and the effective panicles, but decreased the number of grains per panicle, seed setting rate, and 1000-grain weight”
t0“rice (Oryza sativa)”
Claim · model-written summary
D1 and D2 had lower population growth rates during seeding to jointing and heading to maturity.
- Taxon
- riceOryza sativat0
- Treatment
- treatments D1 and D2e0
- Outcome
- population growth ratee0
- Direction
- lowere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The population growth rate was lower in seeding-jointing and heading-maturity stages for treatments D1 and D2”
t0“rice (Oryza sativa)”
Claim · model-written summary
D4 had higher population growth rate during seeding to jointing but insufficient growth thereafter.
- Taxon
- riceOryza sativat0
- Treatment
- treatment D4e0
- Outcome
- population growth ratee1
- Direction
- highere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“higher in seeding-jointing stage for treatment D4 but insufficient in subsequent stages”
e1“The population growth rate was lower”
t0“rice (Oryza sativa)”
Claim · model-written summary
D3 had higher population growth throughout growth, especially from heading to maturity, and achieved high yield.
- Taxon
- riceOryza sativat0
- Treatment
- treatment D3e0
- Outcome
- population growth ratee0
- Direction
- highere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“treatment D3 had higher population growth rate throughout the whole growth stage, especially in heading-maturity stages, ultimately achieving high yield”
t0“rice (Oryza sativa)”
Claim · model-written summary
Densification reduced rice plant height and ear length.
- Taxon
- riceOryza sativat0
- Treatment
- Densificatione0
- Outcome
- plant height and ear lengthe0
- Direction
- reductione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Densification led to a reduction in plant height and ear length”
t0“rice (Oryza sativa)”
Claim · model-written summary
Densification produced slender internodes and thinner base walls.
- Taxon
- riceOryza sativat0
- Treatment
- Densificatione0
- Outcome
- slender internodes and thinner base walle0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Densification led to a reduction in plant height and ear length, as well as slender internodes and thinner base wall”
t0“rice (Oryza sativa)”
Claim · model-written summary
The authors identified 195 seedlings per square metre as optimal for conventional japonica rice.
- Taxon
- riceOryza sativae0
- Material
- conventional japonicae0
- Outcome
- planting density of 195 seedlings m−2e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A planting density of 195 seedlings m−2 was optimal for conventional japonica rice”
Claim · model-written summary
The authors identified 120 seedlings per square metre as optimal for indica–japonica rice.
- Taxon
- riceOryza sativat0
- Material
- indica–japonicae0
- Outcome
- 120 seedlings m−2e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“120 seedlings m−2 for indica–japonica”
t0“rice (Oryza sativa)”
Claim · model-written summary
Increasing rice planting density may compromise lodging resistance while facilitating high yield.
- Taxon
- riceOryza sativae0
- Outcome
- increasing planting density, but may compromise lodging resistancee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Achieving high yield of UAS rice can be facilitated by increasing planting density, but may compromise lodging resistance”
The same questions in other papers
density · yield · Oryza sativa (rice)Positive and negative results
329 papers in the same direction as this paper · 58 in the opposite direction · 7 reporting no difference from an alternative
- positive
- positive
- no effect
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