Abstract
In short-term experiments (10 days), urea applied foliarly as the sole N source promoted growth of `T-5' tomato ( Lycopersicon esculentum Mill.) seedlings. The optimum urea concentration in the spray solution was 0.2% (w/w), and the best application frequency was once a day. Higher urea concentrations suppressed growth, producing severe leaf damage. The growth observed with foliar urea was less than that observed when inorganic N was supplied to the nutrient solution. Tomato seedlings absorbed 75% of the foliar applied urea within 12 hours and 99% within 24 hours after application. Urea concentrations in the plant tissues increased rapidly after foliar application. The maximum concentration was obtained in shoots at 12 hours and in roots at 24 hours after application. After that, concentration in the tissue declined to its original value within 48 hours. Tissue ammonium concentrations also increased after foliar application of urea. Shoot and root ammonium concentrations reached a maximum after 12 hours and stayed constant for the remainder of the 48-hour observation period. In the long-term experiment (5 weeks), the growth obtained with daily foliar applications of urea as the sole N source was only 10% of that when mineral N was available in the nutrient solution. Ammonium concentrations in the tissues of urea-treated plants were higher than those of plants treated with mineral N in the nutrient solution. Although urea concentrations were initially higher in plants treated with mineral N, after 2 weeks urea concentrations declined in these plants and increased in the shoots of plants receiving foliar applications of urea. These results indicate 1) that urea applied foliarly can supply at least part of the N required to sustain growth; 2) that urea is absorbed and assimilated fast enough to alleviate N deprivation; and 3) that failure to promote rapid growth with foliar urea is probably due to phytotoxicity and not to N deprivation.
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Claims 20
Claim · model-written summary
Foliar urea as the sole nitrogen source promoted T-5 tomato seedling growth over 10 days.
- Taxon
- tomato
Solanum lycopersicume0 - Material
- T-5e0
- Treatment
- urea applied foliarly as the sole N sourcee0
- Outcome
- growthe0
- Direction
- promotede0
- Qualifier
- 10 dayse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In short-term experiments (10 days), urea applied foliarly as the sole N source promoted growth of `T-5' tomato ( Lycopersicon esculentum Mill.) seedlings”
Claim · model-written summary
The optimal foliar urea spray concentration was 0.2% (w/w).
- Taxon
- TomatoSolanum lycopersicumt0
- Outcome
- optimum urea concentratione0
- Value
- 0.2% (w/w)e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The optimum urea concentration in the spray solution was 0.2% (w/w)”
t0“Tomato”
Claim · model-written summary
The best foliar application frequency was once a day.
- Taxon
- TomatoSolanum lycopersicumt0
- Outcome
- best application frequencye0
- Value
- once a daye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the best application frequency was once a day”
t0“Tomato”
Claim · model-written summary
Higher urea concentrations suppressed tomato seedling growth.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- Higher urea concentrationse0
- Outcome
- growthe0
- Direction
- suppressede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Higher urea concentrations suppressed growth”
t0“Tomato”
Claim · model-written summary
Higher urea concentrations produced severe leaf damage.
- Taxon
- TomatoSolanum lycopersicumt0
- Organ / stage
- leafe0
- Treatment
- Higher urea concentrationse0
- Outcome
- severe leaf damagee0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Higher urea concentrations suppressed growth, producing severe leaf damage”
t0“Tomato”
Claim · model-written summary
Foliar urea produced less growth than inorganic nitrogen supplied in nutrient solution.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- foliar ureae0
- Outcome
- growthe0
- Direction
- less thane0
- Comparator
- inorganic N was supplied to the nutrient solutione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The growth observed with foliar urea was less than that observed when inorganic N was supplied to the nutrient solution”
t0“Tomato”
Claim · model-written summary
Tomato seedlings absorbed 75% of foliar urea within 12 hours.
- Taxon
- TomatoSolanum lycopersicume0
- Outcome
- absorbede0
- Value
- 75%e0
- Qualifier
- within 12 hourse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Tomato seedlings absorbed 75% of the foliar applied urea within 12 hours”
Claim · model-written summary
Tomato seedlings absorbed 99% of foliar urea within 24 hours.
- Taxon
- TomatoSolanum lycopersicumt0
- Outcome
- after applicatione0
- Value
- 99%e0
- Qualifier
- within 24 hourse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“99% within 24 hours after application”
t0“Tomato”
Claim · model-written summary
Tissue urea concentration rose rapidly after foliar application.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- foliar applicatione0
- Outcome
- Urea concentrations in the plant tissuese0
- Direction
- increased rapidlye0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Urea concentrations in the plant tissues increased rapidly after foliar application”
t0“Tomato”
Claim · model-written summary
Shoot urea concentration peaked at 12 hours after application.
- Taxon
- TomatoSolanum lycopersicumt0
- Organ / stage
- shootse0
- Outcome
- maximum concentratione0
- Direction
- maximume0
- Value
- 12 hourse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The maximum concentration was obtained in shoots at 12 hours”
t0“Tomato”
Claim · model-written summary
Root urea concentration peaked at 24 hours after application.
- Taxon
- TomatoSolanum lycopersicumt0
- Organ / stage
- rootse0
- Outcome
- rootse0
- Value
- 24 hourse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in roots at 24 hours after application”
t0“Tomato”
Claim · model-written summary
Tissue urea concentration returned to its original value within 48 hours.
- Taxon
- TomatoSolanum lycopersicumt0
- Outcome
- concentration in the tissuee0
- Direction
- declinede0
- Value
- 48 hourse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“concentration in the tissue declined to its original value within 48 hours”
t0“Tomato”
Claim · model-written summary
Foliar urea application increased tissue ammonium concentrations.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- foliar application of ureae0
- Outcome
- Tissue ammonium concentrationse0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Tissue ammonium concentrations also increased after foliar application of urea”
t0“Tomato”
Claim · model-written summary
Shoot and root ammonium concentrations peaked at 12 hours and remained constant through 48 hours.
- Taxon
- TomatoSolanum lycopersicumt0
- Outcome
- Shoot and root ammonium concentrationse0
- Direction
- maximume0
- Value
- 12 hourse0
- Qualifier
- stayed constant for the remainder of the 48-hour observation periode0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Shoot and root ammonium concentrations reached a maximum after 12 hours and stayed constant for the remainder of the 48-hour observation period”
t0“Tomato”
Claim · model-written summary
After five weeks, daily foliar urea supported only 10% of growth achieved with mineral nitrogen in solution.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- daily foliar applications of urea as the sole N sourcee0
- Outcome
- growthe0
- Direction
- onlye0
- Value
- 10%e0
- Comparator
- mineral N was available in the nutrient solutione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In the long-term experiment (5 weeks), the growth obtained with daily foliar applications of urea as the sole N source was only 10% of that when mineral N was available in the nutrient solution”
t0“Tomato”
Claim · model-written summary
Urea-treated plants had higher tissue ammonium concentrations than mineral nitrogen-treated plants.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- urea-treated plantse0
- Outcome
- Ammonium concentrations in the tissuese0
- Direction
- highere0
- Comparator
- plants treated with mineral N in the nutrient solutione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Ammonium concentrations in the tissues of urea-treated plants were higher than those of plants treated with mineral N in the nutrient solution”
t0“Tomato”
Claim · model-written summary
Plants treated with mineral nitrogen initially had higher urea concentrations.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- mineral Ne0
- Outcome
- urea concentrationse0
- Direction
- highere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“urea concentrations were initially higher in plants treated with mineral N”
t0“Tomato”
Claim · model-written summary
After two weeks, urea concentration declined in plants receiving mineral nitrogen.
- Taxon
- TomatoSolanum lycopersicumt0
- Outcome
- urea concentrationse0
- Direction
- declinede0
- Qualifier
- after 2 weekse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“after 2 weeks urea concentrations declined in these plants”
t0“Tomato”
Claim · model-written summary
After two weeks, shoot urea concentration increased in foliar-urea plants.
- Taxon
- TomatoSolanum lycopersicumt0
- Organ / stage
- shootse0
- Treatment
- foliar applications of ureae0
- Outcome
- ureae0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased in the shoots of plants receiving foliar applications of urea”
t0“Tomato”
Claim · model-written summary
The authors infer that poor growth with foliar urea is probably due to phytotoxicity rather than nitrogen deprivation.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- foliar ureae0
- Outcome
- failure to promote rapid growthe0
- Qualifier
- probably due to phytotoxicity and not to N deprivatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“failure to promote rapid growth with foliar urea is probably due to phytotoxicity and not to N deprivation”
t0“Tomato”
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See all 253 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.