An Analysis of the Problems of Phytotoxicity, Pesticide Resistance and Pollution from Pesticide Use on Succulents
Foreword
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Thanks to the author [Super Fan] for theoriginal submissionsharing
Submission date: 2018-06-28
Edited and compiled by: Encyclopedia Jun
Location: Weifang City, Shandong Province
After my humble article "The High-Concentration Pesticide Saturation Spraying Method for Rapid Pest Elimination" was published on Succulent Plant Encyclopedia, it sparked lively discussion among many succulent enthusiasts, with some questioning, some affirming, and some left bewildered. On this platform, my impression of Liu Guofeng is no less deep than that of Encyclopedia Jun, and in my mind I have long considered him a kindred spirit. But after all, no one's knowledge can encompass everything, so I will conduct the following in-depth analysis of some of the viewpoints in the comments by Mr. Liu and several others, with the aim of seeking truth and spreading knowledge.
Netizen "Liu Guofeng" commented: "Overdose of pesticide can not only burn succulents and leave aftereffects, but can also cause succulents to develop pesticide resistance, so it really needs attention!"
My analysis is:
1. The phytotoxicity of pesticides to plants is not plant poisoning, but is mostly physical (blocking stomata) and chemical (corrosion) damage. Pesticides and their solvents and adjuvants are all organic substances, and after adding water they form a suspension in water (generally not a solution). After the pesticide is sprayed onto the plant surface, because of dilution by water, whether in terms of pH or osmotic pressure, it is relatively moderate and will not cause damage to the plant. When the water gradually evaporates, the concentration of organic substances gradually increases, and finally they adhere to the plant surface, and only then do they cause harm to the plant, which is the so-called phytotoxicity. However, in three to five minutes the water has not yet completely evaporated, and even if it has already evaporated, because the time is too short and the plant is then rinsed with clean water, it will not cause damage to the plant. Pests, on the other hand, are poisoned by the pesticide; the more pesticide the pests contact, the faster and deeper the poisoning, and the pests will quickly die of poisoning. "High concentration" plus "saturation spraying" is the key to rapid pest elimination.
2. "Succulents developing pesticide resistance" is something we could only wish for, because once succulents are resistant to the pesticide, we can use it freely without worrying about phytotoxicity. But I believe Mr. Liu actually meant that pests develop pesticide resistance, not that "succulents develop pesticide resistance."
What is the mechanism by which pests develop pesticide resistance? There are two factors.
1. Let me use an analogy first: no matter how virulent an infectious disease is, although it can kill most individuals of a species, it will never make that species extinct. For example, in a sufficiently large chicken farm, after a severe outbreak of avian influenza, although large numbers die, there will always be some that stubbornly survive. It turns out that among the individuals of any species there are always some with natural resistance. The same is true of pests: some individuals are born with pesticide resistance.
But pest pesticide resistance differs somewhat from biological resistance to infection by infectious diseases, in that as long as the pesticide dose reaches a certain level, all pests will perish, and no individuals will survive. However, if the dose used is insufficient or the spraying is not thorough, it may kill most pests, while some resistant pests only suffer a serious illness and ultimately pull through. In the offspring of these pests that escaped death, the proportion of resistant individuals will greatly increase. After several repetitions, there will be more and more resistant individuals in the population, and using low-concentration pesticide or even the recommended concentration will no longer produce the expected effect. But this kind of resistance is unstable and reversible; if the pesticide is not used for a long time, the pest population will return to its original sensitive state.
2. After pesticide use, among those pests that escaped death, a few individuals undergo gene mutation due to the stimulation of the pesticide, producing resistance genes. Once a resistance gene appears, this gene will be stably inherited, making their offspring pests that possess the resistance gene. Although this situation is rare, once it forms, it will be stably inherited generation after generation, spreading and running rampant, and using the same pesticide will then only achieve half the result with twice the effort.
What method can prevent pests from developing resistance? That is to completely eliminate the pests, because only dead insects will not develop resistance. Some people advocate mixing the pesticide at a lower concentration when using pesticides to kill pests, which is completely wrong. Killing pests with low-concentration pesticide will only temporarily control the pest population; not only can it not thoroughly eliminate the pests, it is also a breeding ground for cultivating resistant pests, and repeated use of pesticide will actually result in a greater total amount used.
To thoroughly eliminate pests, the pesticide dose must be increased (high concentration is not suitable for large sites such as farmland and gardens; this method is suitable for pest elimination in small areas, and is most suitable for balcony growers). But increasing the pesticide dose will cause phytotoxicity to plants, which creates a contradiction. To resolve this contradiction, my article "The High-Concentration Pesticide Saturation Spraying Method for Rapid Pest Elimination" is a summary of my years of experience and is worth a try.
Netizen "PP" commented: Pesticide flushed directly into the sewer is very likely to cause environmental pollution.
My analysis is:
"Pesticide flushed into the sewer will also cause environmental pollution" is an undeniably true statement, but it is also a meaningless platitude. All pesticides cause pollution; everyone on Earth knows that. But pesticides are still used in large quantities, and factories still produce them in large quantities, because the harm pests cause to humans is more important than pollution. Under current conditions, if modern agriculture were separated from pesticides, it would cause shortages of grain, vegetables, meat, and so on; this is absolutely not alarmist talk. No one wants to return to the primitive society of slash-and-burn farming. Thousands upon thousands of people die in car accidents, and car exhaust is an important source of air pollution, yet no one suggests stopping car production; building aircraft carriers and missiles consumes enormous wealth, and if not for enemies eyeing us covetously, who would not prefer to use it to raise the people's standard of living?
Therefore, we must look at problems in two ways and distinguish the primary from the secondary. It is not that pesticides cannot be used; our goal is to let pesticides play the greatest role and reduce their harm to the minimum. Current pesticides have a residual effect period of about one week; letting them decompose and become ineffective in the sewer, by the time they enter the natural environment they are basically harmless, and less harmful than remaining on the ground. Although pesticide pollution should not be underestimated, the amount of pesticide we balcony growers use is only a trace amount compared with the total, and can be completely ignored.
Netizen "Baoba" commented: Phytotoxicity is fiercer than pest damage; it is just that the visual effect of pest damage looks a bit more frightening.
Regarding the harm of pesticides, most people treat it scientifically, and some say they do not care, but there is also a group of people who turn pale at the mention of pesticides.
Some lawless people abuse pesticides for profit, causing poisoning accidents, and some irresponsible media, chasing rumors and ignoring facts, mislead people, causing some people to develop a mistaken understanding. Such people are overly cautious in life and fear pesticides like tigers, and over time this forms a paranoid mentality, with some even developing into mental illness.
It is true that some pesticides in the past were highly toxic and had long residual effect periods, causing long-term impacts on the ecology (such as organochlorines), but these types have gradually been phased out. The pesticides now approved for production by the state are safe as long as they are applied according to standards. Pesticide pollution cannot be ignored, but most of this pollution comes from abuse. Therefore, we should treat pesticides correctly, and there is no need to turn pale at the mention of them.
Because there are pests, we use pesticides; the key to using pesticide lies in standardization and reasonableness. Weapons are inauspicious instruments; the gentleman uses them only when he has no choice.
The succulents I grow have been free of pests for more than a year now, so I have also not used pesticide for a long time. Some friends have some doubts about my "high concentration," so now I will take a few succulents and do an experiment. This experiment only verifies its safety.
Experimental materials:
Pesticide: beta-cypermethrin and malathion mixture, containing the organophosphate malathion and cypermethrin, with a recommended concentration of 1500-2000 times dilution.
Containers: spray bottle, plastic bucket, plastic basin, syringe.
Succulents: Graptoveria 'Titubans' (white peony), Graptopetalum paraguayense (ghost plant), Echeveria 'Allen', Graptoveria 'Silver Star', and Cremnosedum 'Little Gem' (or a similar white lotus variety).
Add 1000 ml of water to the spray bottle.
Draw 5 ml of pesticide with the syringe.
Add the pesticide to the water and mix in the plastic bucket. This ratio is 200 times dilution, and the concentration is 7.5-10 times the recommended concentration.
Place the succulents into the pesticide solution and start timing.
Put an appropriate amount of clean water in the plastic basin.
After 5 minutes, take the succulents out and place them in the plastic basin, rinse them clean, and then take them out.
Photo taken at the time.
Photo taken the next day, no damage.
Photo taken one week later, completely intact.
Conclusion: Organophosphate pesticides are among the varieties relatively prone to causing phytotoxicity, and this experiment confirms that "The High-Concentration Pesticide Saturation Spraying Method for Rapid Pest Elimination" is safe.
Encyclopedia Jun's chit-chat:Here I thank the author for his "nitpicking" spirit, and I hope more people, like the author, regardless of whether the viewpoint is right or wrong, will personally conduct some experiments after seeing the experiences shared by others. There is a saying in the circle: "There is no great master of Sedum," and only after others' experience and methods have been verified by yourself are they the most accurate experience suitable for you! Finally, one more thing: it just so happens that the movie "Dying to Survive" is quite popular recently, and as soon as I saw this article I changed the title a bit, which also counts as riding a hot topic.
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