Abstract
Abstract Lettuce production in re-circulating hydroponic systems is done on a limited scale in South Africa with conflicting information on the recommended spacing for optimal yield and quality in such systems. The development and yield of four lettuce (Lactuca sativa L.) cultivars ‘NIZ 44–675’, ‘Nou-gatine’, ‘Tango’ and ‘Natividad’ at five different inter- and intra-row spacings namely: 10x20 (50 plants m-2), 10x25 (40 plants m-2), 15×20 (30 plants m-2), 20×20 (25 plants m-2) and 20x25 (20 plants m-2) cm were evaluated during May/June 2008. The experimental layout was a randomized complete block design and each treatment combination was replicated three times. There was a significant interaction between spacing and cultivar regarding leaf fresh and dry mass while all cultivars reacted similarly to different spacings on other yield parameters. Plant population significantly affected plant height, fresh and dry leaf mass, leaf area and leaf number m-2, with significantly higher values of all variables at the closest spacing (50 plants m-2). The results indicate that an increase in plant population results in a significant increase in yield and yield components of leafy lettuce, with all cultivars producing the highest yield at a spacing of 50 plants m- 2 during winter production. Cultivar differences observed showed that ‘NIZ 44–675’ and ‘Tango’ performed better than ‘Nougatine’ and ‘Natividad’, mostly due to higher leaf area, fresh mass, plant height and leaf number.
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Claims 7
Claim · model-written summary
Spacing and cultivar interacted significantly for leaf fresh and dry mass of lettuce.
- Taxon
- Lactuca sativa L.
Lactuca sativae0 - Material
- cultivare1
- Treatment
- spacinge1
- Outcome
- leaf fresh and dry masse1
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“four lettuce (Lactuca sativa L.) cultivars”
e1“There was a significant interaction between spacing and cultivar regarding leaf fresh and dry mass”
Claim · model-written summary
All cultivars reacted similarly to different spacings for the other yield parameters.
- Taxon
- Lactuca sativa L.Lactuca sativae0
- Material
- all cultivarse2
- Treatment
- different spacingse2
- Outcome
- other yield parameterse2
- Direction
- no_changeinferrede2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“four lettuce (Lactuca sativa L.) cultivars”
e2“all cultivars reacted similarly to different spacings on other yield parameters”
Claim · model-written summary
Plant population significantly increased plant height, fresh and dry leaf mass and leaf area of lettuce, with higher values at the closest spacing of 50 plants m-2.
- Taxon
- Lactuca sativa L.Lactuca sativae0
- Treatment
- plant populatione4
- Outcome
- plant height, fresh and dry leaf mass, leaf areae4
- Direction
- significantly highere3
- Qualifier
- at the closest spacing (50 plants m-2)e3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“four lettuce (Lactuca sativa L.) cultivars”
e3“with significantly higher values of all variables at the closest spacing (50 plants m-2)”
e4“Plant population significantly affected plant height, fresh and dry leaf mass, leaf area and leaf number m-2”
Claim · model-written summary
Plant population significantly increased leaf number m-2 of lettuce, with higher values at the closest spacing of 50 plants m-2.
- Taxon
- Lactuca sativa L.Lactuca sativae0
- Treatment
- plant populatione4
- Outcome
- leaf number m-2e4
- Direction
- significantly highere3
- Qualifier
- at the closest spacing (50 plants m-2)e3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“four lettuce (Lactuca sativa L.) cultivars”
e3“with significantly higher values of all variables at the closest spacing (50 plants m-2)”
e4“Plant population significantly affected plant height, fresh and dry leaf mass, leaf area and leaf number m-2”
Claim · model-written summary
An increase in plant population significantly increased yield and yield components of leafy lettuce.
- Taxon
- leafy lettucee5
- Treatment
- increase in plant populatione5
- Outcome
- yield and yield componentse5
- Direction
- significant increasee5
Not reportedComparator
Verbatim
e5“The results indicate that an increase in plant population results in a significant increase in yield and yield components of leafy lettuce”
Claim · model-written summary
All cultivars produced the highest yield at a spacing of 50 plants m- 2 during winter production.
- Taxon
- Lactuca sativa L.Lactuca sativae0
- Material
- all cultivarse6
- Treatment
- a spacing of 50 plants m- 2e6
- Outcome
- yielde6
- Direction
- higheste6
- Setting
- winter productione6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“four lettuce (Lactuca sativa L.) cultivars”
e6“all cultivars producing the highest yield at a spacing of 50 plants m- 2 during winter production”
Claim · model-written summary
Lettuce cultivars NIZ 44–675 and Tango performed better than Nougatine and Natividad, with higher leaf area, fresh mass, plant height and leaf number.
- Taxon
- Lactuca sativa L.Lactuca sativae0
- Material
- ‘NIZ 44–675’ and ‘Tango’e7
- Outcome
- leaf area, fresh mass, plant height and leaf numbere7
- Direction
- highere7
- Comparator
- ‘Nougatine’ and ‘Natividad’e7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“four lettuce (Lactuca sativa L.) cultivars”
e7“‘NIZ 44–675’ and ‘Tango’ performed better than ‘Nougatine’ and ‘Natividad’, mostly due to higher leaf area, fresh mass, plant height and leaf number”
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See all 13 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.