Abstract
Sunflower production can be increased by optimizing agronomic practices that affect production. Plant spacing and sowing time are two important factors affecting sunflower production. To determine the optimum sowing date and plant spacing of native sunflower, an experiment was conducted for one year at the Research Farm of Agricultural Research Center in Rasht, located in north of Iran. Climatically, the area has a mild and humid climate with variable rainfall throughout the year. The average rainfall during the year is 1359 mm. The experiment was laid out as a randomized complete block design with three replications. The treatments were two planting dates (25th April and 15th May), and four plant spacing (75 cm ×20 cm, 65 cm ×23 cm, 50 cm ×30 cm, 35 cm ×43 cm) with equal plant density. The results showed significant effects of planting date and plant spacing on yield and yield components of native sunflower. The earlier planting date was shown to give better seed yields than later planting. The later planting date resulted in decreased yield of sunflower but increased straw yield. Also number of infertile seeds/head was lower at the early planting time. At all plant spacing the early planting gave a superior harvest index compared to the later planting. Increasing row spacing resulted in increasing yield. The highest seed yield (2489 kg/ha) and harvest index (18.93%) were obtained from the early planting date at the 75 cm ×20 cm plant spacing. A delay of the planting date significantly decreased grain yield of sunflower due to a decrease in the number of seeds per head and in seed weight and seed yield.
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Claims 12
Claim · model-written summary
Planting date and spacing significantly affected sunflower yield and yield components.
- Taxon
- sunflower
Helianthus annuuse0 - Treatment
- planting date and plant spacinge0
- Outcome
- yield and yield componentse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“significant effects of planting date and plant spacing on yield and yield components of native sunflower”
Claim · model-written summary
Earlier planting produced better seed yields than later planting.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- earlier planting datee0
- Outcome
- seed yieldse0
- Direction
- bettere0
- Comparator
- later plantinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The earlier planting date was shown to give better seed yields than later planting.”
t0“sunflower”
Claim · model-written summary
Later planting decreased sunflower yield.
- Taxon
- sunflowerHelianthus annuuse0
- Treatment
- later planting datee0
- Outcome
- yielde0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The later planting date resulted in decreased yield of sunflower”
t0“sunflower”
Claim · model-written summary
Later planting increased sunflower straw yield.
- Taxon
- sunflowerHelianthus annuuse0
- Treatment
- later planting datee0
- Outcome
- straw yielde0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The later planting date resulted in decreased yield of sunflower but increased straw yield.”
t0“sunflower”
Claim · model-written summary
Early planting lowered infertile seeds per head.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- early planting timee0
- Outcome
- number of infertile seeds/heade0
- Direction
- lowere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“number of infertile seeds/head was lower at the early planting time”
t0“sunflower”
Claim · model-written summary
Early planting gave a superior harvest index at all spacings.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- early plantinge0
- Outcome
- harvest indexe0
- Direction
- superiore0
- Qualifier
- At all plant spacinge0
- Comparator
- later plantinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“At all plant spacing the early planting gave a superior harvest index compared to the later planting.”
t0“sunflower”
Claim · model-written summary
Increasing row spacing increased yield.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- Increasing row spacinge0
- Outcome
- yielde0
- Direction
- increasinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Increasing row spacing resulted in increasing yield.”
t0“sunflower”
Claim · model-written summary
Early planting at 75 cm ×20 cm yielded the highest seed yield, 2489 kg/ha.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- early planting date at the 75 cm ×20 cm plant spacinge0
- Outcome
- seed yielde0
- Direction
- higheste0
- Value
- 2489 kg/hae0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The highest seed yield (2489 kg/ha) and harvest index (18.93%) were obtained from the early planting date at the 75 cm ×20 cm plant spacing.”
t0“sunflower”
Claim · model-written summary
Early planting at 75 cm ×20 cm produced the highest harvest index, 18.93%.
- Taxon
- sunflowerHelianthus annuust0
- Treatment
- early planting date at the 75 cm ×20 cm plant spacinge0
- Outcome
- harvest indexe0
- Direction
- higheste0
- Value
- 18.93%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The highest seed yield (2489 kg/ha) and harvest index (18.93%) were obtained from the early planting date at the 75 cm ×20 cm plant spacing.”
t0“sunflower”
Claim · model-written summary
Planting delay significantly reduced grain yield.
- Taxon
- sunflowerHelianthus annuuse0
- Treatment
- A delay of the planting datee0
- Outcome
- grain yielde0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A delay of the planting date significantly decreased grain yield of sunflower”
t0“sunflower”
Claim · model-written summary
Planting delay reduced seeds per head, which the authors linked to lower grain yield.
- Taxon
- sunflowerHelianthus annuuse0
- Treatment
- A delay of the planting datee0
- Outcome
- number of seeds per heade0
- Direction
- decreasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A delay of the planting date significantly decreased grain yield of sunflower due to a decrease in the number of seeds per head and in seed weight and seed yield.”
Claim · model-written summary
Planting delay reduced seed weight, which the authors linked to lower grain yield.
- Taxon
- sunflowerHelianthus annuuse0
- Treatment
- A delay of the planting datee0
- Outcome
- seed weighte0
- Direction
- decreasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A delay of the planting date significantly decreased grain yield of sunflower due to a decrease in the number of seeds per head and in seed weight and seed yield.”
The same questions in other papers
sowing time · yield · Helianthus annuus (common sunflower)Positive and negative results
38 papers in the same direction as this paper · 13 in the opposite direction · 1 reporting no difference from an alternative
- negative
- positive
- positive
49 papers more in this group
See all 53 papers →density · yield · Helianthus annuus (common sunflower)Positive and negative results
69 papers in the same direction as this paper · 15 in the opposite direction
- negative
- positive
- no effect
81 papers more in this group
See all 85 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.