Abstract
Nitrogen (N) supply and harvest timing through ‘reaping and re-growth’ method are critical determinants of yield and quality in hydroponically grown leafy vegetables. Lettuce (Lactuca sativa L.) was chosen as a test crop for evaluating the effect of nitrogen applications and harvesting times. In India, farmers often apply N without guidance and improperly harvest leafy vegetables. Therefore, it is essential to determine the optimum N supply and harvesting time for yield and quality enhancement of hydroponically grown lettuce. We studied the effect of different levels of N (4, 6, 8 and 10 mmolL−1) and two harvest timings on the growth attributes and quality of lettuce. The higher N levels (10 and 8 mmolL−1) showed pronounced positive effects on growth, yield, and quality of lettuce. However, the dry matter yield and ascorbic acid content decreased with the increase in N levels. For a continuous supply of fresh cut leaves of lettuce and to optimize leaf nitrate content, the plants has to be harvested by adapting cut and come again method during winter season. The average growth rate, showed significant positive response to N. The present study demonstrates that optimum levels of N (10 mmolL−1) and harvest through cutting (after 45 days of harvesting) significantly increase the leaf yield and quality of the lettuce.
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 7
Claim · model-written summary
Higher nitrogen levels improved lettuce growth, yield and quality.
- Taxon
- lettuce
Lactuca sativae0 - Treatment
- higher N levels (10 and 8 mmolL−1)e0
- Outcome
- growth, yield, and qualitye0
- Direction
- positive effectse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The higher N levels (10 and 8 mmolL−1) showed pronounced positive effects on growth, yield, and quality of lettuce.”
Claim · model-written summary
Dry matter yield decreased as nitrogen levels increased.
- Taxon
- lettuceLactuca sativat0
- Treatment
- increase in N levelse0
- Outcome
- dry matter yielde0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the dry matter yield and ascorbic acid content decreased with the increase in N levels.”
t0“lettuce”
Claim · model-written summary
Ascorbic acid content decreased as nitrogen levels increased.
- Taxon
- lettuceLactuca sativat0
- Treatment
- increase in N levelse0
- Outcome
- ascorbic acid contente0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the dry matter yield and ascorbic acid content decreased with the increase in N levels.”
t0“lettuce”
Claim · model-written summary
Average growth rate responded positively to nitrogen.
- Taxon
- lettuceLactuca sativat0
- Treatment
- Ne0
- Outcome
- average growth ratee0
- Direction
- positive responsee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The average growth rate, showed significant positive response to N.”
t0“lettuce”
Claim · model-written summary
The authors recommend cut and come again harvest in winter for continuous leaves and optimized leaf nitrate content.
- Taxon
- lettuceLactuca sativae0
- Outcome
- cut and come again methode0
- Qualifier
- winter seasone0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“For a continuous supply of fresh cut leaves of lettuce and to optimize leaf nitrate content, the plants has to be harvested by adapting cut and come again method during winter season.”
Claim · model-written summary
Nitrogen at 10 mmolL−1 significantly increased lettuce leaf yield and quality.
- Taxon
- lettuceLactuca sativae0
- Treatment
- N (10 mmolL−1)e0
- Outcome
- leaf yield and qualitye0
- Direction
- increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“optimum levels of N (10 mmolL−1) and harvest through cutting (after 45 days of harvesting) significantly increase the leaf yield and quality of the lettuce.”
Claim · model-written summary
Harvest through cutting after 45 days significantly increased lettuce leaf yield and quality.
- Taxon
- lettuceLactuca sativae0
- Treatment
- harvest through cutting (after 45 days of harvesting)e0
- Outcome
- leaf yield and qualitye0
- Direction
- increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“optimum levels of N (10 mmolL−1) and harvest through cutting (after 45 days of harvesting) significantly increase the leaf yield and quality of the lettuce.”
The same questions in other papers
nitrogen · quality: general · Lactuca sativa (garden lettuce)Positive and negative results
6 papers in the same direction as this paper · 2 in the opposite direction
- no effect
- negative
- positive
5 papers more in this group
See all 9 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.