Seedling Responses to Organically-Derived Plant Growth Promoters: An Effects-Based Approach

Organically-derived biofertilizers and biostimulants, developed from harvested materials such as seaweed and waste from animal and fish processing, are currently the subject of much fundamental and applied research. These products have significant potential in reducing synthetic fertilizer inputs to horticultural, arable, and pasture-based agricultural systems, although there is frequently some ambiguity over the magnitude and consistency of any positive effects these products may have on plant performance. This study examined the effects of organically-derived plant growth promoters (PGPs) available in New Zealand on the early vegetative growth of 16 plant species maintained under glasshouse conditions. When applied as a root drench to low nutrient potting mix, the effects of the PGPs on seedling shoot growth were strongly related to the NPK contents of the applied solutions. Any positive effects on shoot growth were, on average, reduced when the seedlings were maintained in higher nutrient growing media. Applying the PGPs at concentrations twice, and four times, the recommended concentration, only caused further growth responses when the PGPs contained high levels of nutrients. Applying the PGPs as a foliar spray had negligible effects on shoot growth. Overall, the results of these trials suggest that the positive effects of applying some organically-derived PGPs on seedling growth are a function of the PGP nutrient content, and not due to any indirect effects related to phytohormone pathways or modification of rhizosphere microorganisms.

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Foliar Spray of Natural and Synthetic Plant Growth Promoters Accelerates Growth and Yield of Cotton by Modulating Photosynthetic Pigments

International Journal of Plant Production ◽

10.1007/s42106-021-00158-0 ◽

2021 ◽

Author(s):

Muhammad Shaukat ◽

Ashfaq Ahmad ◽

Tasneem Khaliq ◽

Irfan Afzal ◽

Sher Muhammad ◽

...

Keyword(s):

Plant Growth ◽

Photosynthetic Pigments ◽

Foliar Spray ◽

Growth And Yield ◽

Growth Promoters ◽

Plant Growth Promoters ◽

Natural And Synthetic

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Trichoderma Secondary Metabolites that Affect Plant Metabolism

Natural Product Communications ◽

10.1177/1934578x1200701133 ◽

2012 ◽

Vol 7 (11) ◽

pp. 1934578X1200701 ◽

Cited By ~ 8

Author(s):

Francesco Vinale ◽

Krishnapillai Sivasithamparam ◽

Emilio L. Ghisalberti ◽

Michelina Ruocco ◽

Sheridan Woo ◽

...

Keyword(s):

Secondary Metabolites ◽

Plant Growth ◽

Biological Activities ◽

Plant Metabolism ◽

Growth Promoters ◽

Plant Host ◽

Trichoderma Spp ◽

Positive Effects ◽

Complex Interactions ◽

Plant Growth Promoters

Recently, there have been many exciting new developments relating to the use of Trichoderma spp. as agents for biocontrol of pathogens and as plant growth promoters. Several mechanisms have been proposed to explain the positive effects of these microorganisms on the plant host. One factor that contributes to their beneficial biological activities is related to the wide variety of metabolites that they produce. These metabolites have been found not only to directly inhibit the growth and pathogenic activities of the parasites, but also to increase disease resistance by triggering the system of defence in the plant host. In addition, these metabolites are also capable of enhancing plant growth, which enables the plant to counteract the disease with compensatory vegetative growth by the augmented production of root and shoot systems. This review takes into account the Trichoderma secondary metabolites that affect plant metabolism and that may play an important role in the complex interactions of this biocontrol agent with the plant and pathogens.

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Seaweeds’ carbohydrate polymers as plant growth promoters

Carbohydrate Polymer Technologies and Applications ◽

10.1016/j.carpta.2021.100097 ◽

2021 ◽

pp. 100097

Author(s):

Diana Pacheco ◽

João Cotas ◽

Carolina P. Rocha ◽

Glacio S. Araújo ◽

Artur Figueirinha ◽

...

Keyword(s):

Plant Growth ◽

Growth Promoters ◽

Carbohydrate Polymers ◽

Plant Growth Promoters

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Wheat seeds harbour bacterial endophytes with potential as plant growth promoters and biocontrol agents of Fusarium graminearum

Microbiological Research ◽

10.1016/j.micres.2016.03.002 ◽

2016 ◽

Vol 186-187 ◽

pp. 37-43 ◽

Cited By ~ 78

Author(s):

Silvana Díaz Herrera ◽

Cecilia Grossi ◽

Myriam Zawoznik ◽

María Daniela Groppa

Keyword(s):

Plant Growth ◽

Fusarium Graminearum ◽

Biocontrol Agents ◽

Bacterial Endophytes ◽

Growth Promoters ◽

Plant Growth Promoters ◽

Wheat Seeds

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Growth responses of Leymus chinensis (Trin.) Tzvelev to sheep saliva after defoliation

The Rangeland Journal ◽

10.1071/rj09061 ◽

2010 ◽

Vol 32 (4) ◽

pp. 419 ◽

Cited By ~ 5

Author(s):

Xing Teng ◽

Lei Ba ◽

Deli Wang ◽

Ling Wang ◽

Jushan Liu

Keyword(s):

Plant Growth ◽

Aboveground Biomass ◽

Field Experiments ◽

Perennial Grass ◽

Leaf Length ◽

Leymus Chinensis ◽

Growth Responses ◽

Time Duration ◽

Positive Effects ◽

Leaf Weight

Many studies indicated that saliva from herbivores might be involved in plant growth responses when plants have been grazed. However, there is currently no general agreement on whether saliva can affect plant growth. Our aims were to determine the growth response of plants to sheep saliva after defoliation under diverse environmental conditions (different sward structures), and whether the effect of saliva is influenced by time (duration) after its application. We conducted field experiments with clipping treatments and the application of sheep saliva to the damaged parts of tillers to simulate sheep grazing on the perennial grass Leymus chinensis (Trin.) Tzvelev during the early growing seasons. Results demonstrated that clipping with saliva application significantly increased tiller numbers 8 weeks after treatments in comparison with clipping alone. A key finding is that the effect of sheep saliva on plant growth was short-lived. Clipping with saliva application increased leaf weight in the second week, while clipping alone had no effect. Moreover, clipping with saliva application promoted the elongation of new leaves (not the old ones) in the first week whereas clipping alone was ineffective. Results also showed that there were no differences between clipping with saliva application and clipping alone for relative height growth rate and aboveground biomass. Therefore, we concluded that saliva application to clipping treatment would produce an additional effect compared to clipping alone for the plant and the positive effects are time dependent. The additional effects primarily embodied in the individual level of plant, such as the changes of leaf weight and leaf length. Beyond the level, the effects of saliva only produced many more tiller numbers rather than the accumulation of aboveground biomass.

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