“Pests and diseases have caused significant problems since the domestication of crops, resulting in economic loss and hunger. To overcome these problems, synthetic pesticides were developed to control pests; however, there are significant detrimental side effects of synthetic pesticides on the environment and human health. There is an urgent need to develop safer and more sustainable pesticides.
Industrial hemp is a reservoir of compounds that could potentially replace some synthetic bactericides, fungicides, and insecticides.
We determined the efficacy of industrial hemp extracts against Pseudomonas syringae pv. tabaci (PSTA), Pseudomonas syringae pv. tomato (PSTO), and Erwinia carotovora (EC).
The study revealed a minimum inhibitory concentration (MIC) of 2.05 mg/mL and a non-inhibitory concentration (NIC) of 1.2 mg/mL for PSTA, an MIC of 5.7 mg/mL and NIC of 0.66 mg/mL for PSTO, and an MIC of 12.04 mg/mL and NIC of 5.4 mg/mL for EC. Time-kill assays indicated the regrowth of E. carotovora at 4 × MIC after 15 h and P. syringae pv. tomato at 2 × MIC after 20 h; however, P. syringae pv. tabaci had no regrowth. The susceptibility of test bacteria to hemp extract can be ordered from the most susceptible to the least susceptible, as follows: P. syringae pv. tabaci > P. syringae pv. tomato > E. carotovora.
Overall, the data indicate hemp extract is a potential source of sustainable and safe biopesticides against these major plant pathogens.”
https://pubmed.ncbi.nlm.nih.gov/39769990/
“The data show the susceptibility of the test bacteria to hemp extract, ordered from the most susceptible to the least susceptible, as follows: P. syringae pv. tabaci > P. syringae pv. tomato > E. carotovora.
This study indicates that hemp extract is effective in controlling E. carotovora, P. syringae pv. tabaci, and P. syringae pv. tomato. However, the hemp extract is more effective against both Pseudomonas spp. than E. carotovora. The difference could be due to their difference in cell wall structure, resistance mechanisms, and metabolic pathways.
More studies are needed to determine how hemp extract causes stress to bacteria such as interference with quorum sensing, biofilm formation, and oxidative stress. Moreover, to ensure sustainable agricultural practices that are safe and affordable for low-income farmers, synergistic effect studies are needed between hemp compounds in the extract and, more importantly, between hemp extracts and other plant extracts.”