Abstract
1. Effects of potassium deficiency were studied in sunflower plants grown in sand cultures. The first symptom observed was a deeper-green color of the leaves. Later, lower leaves became chlorotic, the decrease in chlorophyll starting at the tips and edges and then extending inward and toward the base. Chlorosis was followed by necrosis of the tissue. Minus-potassium plants were stunted, with small leaves and short, thin stems. No difference in hardness of stems of the two sets of plants was noticed. Potassium deficiency affected tops more than roots, and growth of stems was limited more than that of leaves. Thus, top-root ratios of minus-potassium plants were lower and leaf-stem ratios were higher than those of plus-potassium plants. 2. Potassium-starved leaves and stems tended to be lower in water content than those with complete nutrient. In general, total nitrogen, soluble nitrogen, and nitrates were higher in leaves and stems of the latter than of the former. In the middle and lower stems of the third harvest, however, both total nitrogen and soluble nitrogen were higher in the former plants. Ammonia and amides accumulated in minus-potassium leaves and stems, although the amide percentages were rather low. Their accumulation at early stages in the deficiency may have resulted mainly from interference with protein synthesis at the amide stage; at late stages, proteolysis was probably an additional important factor. 3. Total sugars and reducing sugars were high in minus-potassium leaves throughout the experiment. This was true also of stems of the first harvest, but differences lessened as the deficiency developed and at the third harvest were in favor of the plus-potassium stems, owing to the low reducing sugar content of potassium-starved stems. Sucrose was uniformly higher in minus-potassium leaves and stems than in plus-potassium ones. Starch did not vary much in the two groups of plants. When all carbohydrates were included and calculated for either tops or stems, the no-potassium plants were high in carbohydrates in comparison with those on complete nutrient at the first harvest but low at the final harvest. Accumulation of carbohydrates early in the deficiency may have resulted both from the interference with protein synthesis at the amide stage and from the greater leaf-stem ratio. The low carbohydrate content at late stages may have been a consequence of reduced photosynthesis and increased respiration. 4. At the final harvest potassium could be detected only in leaves and upper stems of the minus-potassium plants. It was well distributed throughout tops of the plus-potassium plants at all times, being even more concentrated in middle and lower stems than in upper. Most of the potassium in the leaves and stems of each set of plants was removed by seven extractions with 70% alcohol. Potassium seemed to be readily translocated in potassium-starved plants as indicated by its differential distribution in the two sets of stems and by the fact that plants grown for 66 days with a minus-potassium solution developed small flower heads.
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 20
Claim · model-written summary
Potassium-deficient leaves first became deeper green, then chlorotic and necrotic.
- Taxon
- Sunflower
Helianthus annuust0 - Treatment
- potassium deficiencyt0
- Outcome
- deeper-green color of the leavese0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The first symptom observed was a deeper-green color of the leaves. Later, lower leaves became chlorotic, the decrease in chlorophyll starting at the tips and edges and then extending inward and toward the base. Chlorosis was followed by necrosis of the tissue.”
t0“Effects of Potassium Deficiency on Growth and Metabolism of Sunflower Plants.”
Claim · model-written summary
Potassium-deficient sunflower plants were stunted with small leaves and short thin stems.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- Minus-potassiume1
- Outcome
- stunted, with small leaves and short, thin stemse1
- Direction
- stuntede1
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Minus-potassium plants were stunted, with small leaves and short, thin stems.”
t0“Sunflower Plants”
Claim · model-written summary
Stem hardness showed no difference between potassium treatments.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- Potassium Deficiencyt0
- Outcome
- hardness of stemse2
- Direction
- No differencee2
- Comparator
- two sets of plantse2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“No difference in hardness of stems of the two sets of plants was noticed.”
t0“Effects of Potassium Deficiency on Growth and Metabolism of Sunflower Plants.”
Claim · model-written summary
Potassium deficiency affected tops more than roots and stem growth more than leaf growth.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- Potassium deficiencye3
- Outcome
- topse3
- Direction
- more thane3
- Comparator
- rootse3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e3“Potassium deficiency affected tops more than roots, and growth of stems was limited more than that of leaves.”
t0“Sunflower Plants”
Claim · model-written summary
Minus-potassium plants had lower top-root ratios and higher leaf-stem ratios.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- minus-potassiume4
- Outcome
- top-root ratiose4
- Direction
- lowere4
- Comparator
- plus-potassium plantse4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“top-root ratios of minus-potassium plants were lower and leaf-stem ratios were higher than those of plus-potassium plants.”
t0“Sunflower Plants”
Claim · model-written summary
Minus-potassium plants had higher leaf-stem ratios.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- minus-potassium plantse6
- Outcome
- leaf-stem ratiose5
- Direction
- highere5
- Comparator
- plus-potassium plantse5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e5“leaf-stem ratios were higher than those of plus-potassium plants.”
t0“Sunflower Plants”
e6“top-root ratios of minus-potassium plants”
Claim · model-written summary
Potassium-starved leaves and stems tended toward lower water content.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- Potassium-starvede7
- Outcome
- water contente7
- Direction
- lowere7
- Comparator
- complete nutriente7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“Potassium-starved leaves and stems tended to be lower in water content than those with complete nutrient.”
t0“Sunflower Plants”
Claim · model-written summary
Total nitrogen, soluble nitrogen and nitrates were generally higher with complete nutrient than under potassium starvation.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- Potassium-starvede1
- Outcome
- total nitrogen, soluble nitrogen, and nitratese0
- Direction
- highere0
- Comparator
- complete nutriente1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In general, total nitrogen, soluble nitrogen, and nitrates were higher in leaves and stems of the latter than of the former.”
e1“Potassium-starved leaves and stems tended to be lower in water content than those with complete nutrient.”
t0“Sunflower Plants”
Claim · model-written summary
At the third harvest, total and soluble nitrogen were higher in potassium-starved middle and lower stems.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- Potassium-starvede3
- Outcome
- total nitrogen and soluble nitrogene2
- Direction
- highere2
- Qualifier
- third harveste2
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“In the middle and lower stems of the third harvest, however, both total nitrogen and soluble nitrogen were higher in the former plants.”
e3“Potassium-starved leaves and stems”
t0“Sunflower Plants”
Claim · model-written summary
Ammonia and amides accumulated in potassium-deficient leaves and stems.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- minus-potassiume4
- Outcome
- Ammonia and amidese4
- Direction
- accumulatede4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“Ammonia and amides accumulated in minus-potassium leaves and stems, although the amide percentages were rather low.”
t0“Sunflower Plants”
Claim · model-written summary
Total and reducing sugars were high in deficient leaves throughout the experiment.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- minus-potassiume5
- Outcome
- Total sugars and reducing sugarse5
- Direction
- highe5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e5“Total sugars and reducing sugars were high in minus-potassium leaves throughout the experiment.”
t0“Sunflower Plants”
Claim · model-written summary
Stems initially had high sugars under potassium deficiency, but by the third harvest potassium-starved stems had low reducing sugar.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- potassium-starvede6
- Outcome
- reducing sugar contente6
- Direction
- lowe6
- Qualifier
- third harveste6
- Comparator
- plus-potassium stemse6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e6“This was true also of stems of the first harvest, but differences lessened as the deficiency developed and at the third harvest were in favor of the plus-potassium stems, owing to the low reducing sugar content of potassium-starved stems.”
t0“Sunflower Plants”
Claim · model-written summary
Sucrose was higher in deficient leaves and stems.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- minus-potassiume7
- Outcome
- Sucrosee7
- Direction
- highere7
- Comparator
- plus-potassium onese7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“Sucrose was uniformly higher in minus-potassium leaves and stems than in plus-potassium ones.”
t0“Sunflower Plants”
Claim · model-written summary
Starch varied little between potassium treatments.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- Potassium Deficiencyt0
- Outcome
- Starche0
- Direction
- did not vary muche0
- Comparator
- two groups of plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Starch did not vary much in the two groups of plants.”
t0“Effects of Potassium Deficiency on Growth and Metabolism of Sunflower Plants.”
Claim · model-written summary
Total carbohydrates in deficient tops or stems were high at first harvest.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- no-potassiume1
- Outcome
- carbohydratese1
- Direction
- highe1
- Qualifier
- first harveste1
- Comparator
- complete nutriente1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“the no-potassium plants were high in carbohydrates in comparison with those on complete nutrient at the first harvest but low at the final harvest.”
t0“Sunflower Plants”
Claim · model-written summary
Total carbohydrates in deficient tops or stems were low at final harvest.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- no-potassiume2
- Outcome
- carbohydratese2
- Direction
- lowe2
- Qualifier
- final harveste2
- Comparator
- complete nutriente2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e2“the no-potassium plants were high in carbohydrates in comparison with those on complete nutrient at the first harvest but low at the final harvest.”
t0“Sunflower Plants”
Claim · model-written summary
At final harvest potassium was detectable only in deficient leaves and upper stems.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- minus-potassiume3
- Outcome
- potassium could be detected only in leaves and upper stemse3
- Qualifier
- final harveste3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e3“At the final harvest potassium could be detected only in leaves and upper stems of the minus-potassium plants.”
t0“Sunflower Plants”
Claim · model-written summary
Potassium was distributed throughout plus-potassium tops, with more in middle and lower stems than upper stems.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- plus-potassiume4
- Outcome
- well distributed throughout topse4
- Direction
- more concentratede4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“It was well distributed throughout tops of the plus-potassium plants at all times, being even more concentrated in middle and lower stems than in upper.”
e5“potassium could be detected”
t0“Sunflower Plants”
Claim · model-written summary
Seven 70% alcohol extractions removed most potassium from leaves and stems.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- seven extractions with 70% alcohole6
- Outcome
- potassium in the leaves and stemse6
- Direction
- removede6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e6“Most of the potassium in the leaves and stems of each set of plants was removed by seven extractions with 70% alcohol.”
t0“Sunflower Plants”
Claim · model-written summary
Potassium-starved plants developed small flower heads after 66 days, suggesting potassium translocation.
- Taxon
- SunflowerHelianthus annuust0
- Treatment
- minus-potassium solutione7
- Outcome
- small flower headse7
- Qualifier
- 66 dayse7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“Potassium seemed to be readily translocated in potassium-starved plants as indicated by its differential distribution in the two sets of stems and by the fact that plants grown for 66 days with a minus-potassium solution developed small flower heads.”
t0“Sunflower Plants”
The same questions in other papers
potassium · soil: physics · Helianthus annuus (common sunflower)Positive and negative results
1 in the opposite direction
- positive
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.