Abstract
The increasing demands for biostimulants in the agricultural market over the last years have posed the problem of regulating this product category by requiring the industry to make available the information about efficacy and safety, including the explanation of mode of action and the definition of bioactive constituents. In the present study, we tested the biostimulant proprieties of a sedimentary shale ore-extracted humic acid (HA) on Micro Tom tomato plants under increasing nutritional stress and investigated the correlation with the chemical features of HA by means of ultra-high resolution FT-ICR MS, FT-ATR, and 13 C-NMR. Humic acid application proved effective in alleviating the nutritional stress by improving nutrient use efficiency, with results comparable to the control treatment supplied with higher NPK nutrition. Increased yield (up to +19%) and fruit quality (in the range +10–24%), higher ascorbic acid content and a better root growth were the main parameters affected by HA application. Molecular-level characterization identified the possible chemical drivers of bioactivity, and included flavonoids, quinones, and alkaloids among the most represented molecules, some of which exhibiting antioxidant, pro-oxidant, and antimicrobial activity. The redox effect was discussed as a determinant of the delicate homeostasis balance, capable of triggering plant defense response and eventually inducing a protective priming effect on the plants.
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Claims 6
Claim · model-written summary
Humic acid improved nutrient use efficiency under nutritional stress.
- Taxon
- tomato
Solanum lycopersicumt0 - Treatment
- Humic acid applicatione0
- Outcome
- nutrient use efficiencye0
- Direction
- improvinge0
- Comparator
- control treatment supplied with higher NPK nutritione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Humic acid application proved effective in alleviating the nutritional stress by improving nutrient use efficiency, with results comparable to the control treatment supplied with higher NPK nutrition.”
t0“tomato”
Claim · model-written summary
Humic acid increased tomato yield by up to 19%.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- HA applicatione0
- Outcome
- yielde0
- Direction
- Increasede0
- Value
- up to +19%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato Plant Yield”
e0“Increased yield (up to +19%) and fruit quality (in the range +10–24%), higher ascorbic acid content and a better root growth were the main parameters affected by HA application.”
Claim · model-written summary
Humic acid increased fruit quality by 10–24%.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- HA applicatione0
- Outcome
- fruit qualitye0
- Direction
- increaseinferrede0
- Value
- in the range +10–24%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato Plant Yield”
e0“Increased yield (up to +19%) and fruit quality (in the range +10–24%), higher ascorbic acid content and a better root growth were the main parameters affected by HA application.”
Claim · model-written summary
Humic acid raised ascorbic acid content.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- HA applicatione0
- Outcome
- ascorbic acid contente0
- Direction
- highere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato Plant Yield”
e0“higher ascorbic acid content and a better root growth were the main parameters affected by HA application.”
Claim · model-written summary
Humic acid improved root growth.
- Taxon
- TomatoSolanum lycopersicumt0
- Treatment
- HA applicatione0
- Outcome
- root growthe0
- Direction
- bettere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato Plant Yield”
e0“higher ascorbic acid content and a better root growth were the main parameters affected by HA application.”
Claim · model-written summary
Molecular characterization identified flavonoids, quinones and alkaloids among prominent humic acid molecules.
- Taxon
- TomatoSolanum lycopersicumt0
- Outcome
- flavonoids, quinones, and alkaloids among the most represented moleculese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Tomato Plant Yield”
e0“Molecular-level characterization identified the possible chemical drivers of bioactivity, and included flavonoids, quinones, and alkaloids among the most represented molecules”
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