There seems to be a mountain of research literature published on the topic of Salicylic Acid, Jasmonic Acid, SAR, various pathogens and the efficacy of various strategies in inducing these healing states in different plants. Personally, I came upon the concept of SAR while informally studying Pseudomonas siringae and the effect of UV light for a post on this forum and have come to understand that there is a great deal of highly specialized knowledge and interactive complexity which rears itself immediately upon diving into this topic.
I wonder if there is something of a divide in need of bridging between the people doing this research and the agriculturalist. In my mind, having free access to research publications is a tremendous asset and serves to partially erase the divide if the right questions are asked. I have been finding that each question leads to numerous others and one can begin to sense a phantasmic model of how things tend to interrelate and operate.
To the topic of willow water: I came across this forum topic outside of the site in the course of searching for and reading about the apparent consensus on the effectiveness of exogenic (originating from outside) applications of Salicylic Acid in inducing a SAR state.
As the article above states, willow (Salix sp.) is a potent source of Salicylic Acid and a tea of branch cuttings has long been used as a very effective rooting hormone. I am interested in the use of SA as a supplemental input in compost teas, root drenches, and as a potential foliar spray additive to create a kind of latent SAR boost. The article gives the appropriate ratio for a foliar spray as 1/10,000 which is formulated as 3 aspirin dissolved in 4 gallons of water. Personally, I may even go with an even greater dilution for a weaker and more subtle supplemental effect as a tea ingredient or as a constituent in an ongoing spray regimen on healthy trees and plants...
Generally speaking, a plant will respond to a microbial pathogen by triggering something called a Hypersensitive Response (HR). If I understand this correctly, the HR trigger results in localized cell death, the production of what are known as reactive oxygen species (peroxides, superoxide, hydroxyl radical, and singlet oxygen), and the production of antimicrobial compounds at the infection site. This is interesting when one observes the visual symptoms of Pseudomonas Siringae, as it seems that certain aspects of the disease symptoms are potentially the results of the plants healing response (sunken dead patches in bark). The HR state is accompanied by a secondary resistance response, SAR. SAR is triggered by endogenic hormonal Salicylic Acid in uninfected tissues and establishes persistent resistance to a wide range of subsequent pathogens.
There is another topic on this forum called
"Green Immune Function" exploring all of this and I may copy, paste, edit, and reorganize this posting into a new one in that thread which outlines some of the stuff I have been reading about within this realm of inquiry and would like to discuss.
Karn Piana
Zone 7 Semi-Arid Steppe
Northern New Mexico
Edited 6 time(s). Last edit at 07/17/2018 09:42AM by Karn Piana.