A Detailed Guide to Orchid Medications, Part Two: Understanding Stroby

Whenever temperatures rise from low to high and humidity increases along with them, the fungi that harm orchid leaves also begin to become active. Often, more than one kind of fungus harms orchid leaves at the same time; it is just that the severity of the damage and how early they are detected differ. When various harmful fungi attack orchid leaves either simultaneously or in succession, people are often left running around trying to cope, attending to one problem only to neglect another. Because the commonly used medications for controlling leaf surface fungal damage have been in use for a relatively long time, harmful fungi have gradually developed resistance to these medications, making it necessary to increase the concentration and frequency of application to achieve the goal of eliminating the harmful fungi. The harmful fungi may have been eliminated or temporarily brought under control, but at this pointthe orchid plantis under tremendous toxic stress, which affects its normal growth. For controlling fungal damage on orchid leaves, Yaoyuan adopted a green, environmentally friendly, pollution-free biological fungicide - Stroby. The active ingredient, effects and characteristics, target pests and diseases, usage methods, and precautions of Stroby are introduced as follows: Active ingredient: Stroby is synthesized based on strobilurin, a metabolite of the fungus Armillaria on the mucus of larch cones. The chemical structure of this active ingredient was discovered in 1978, and in 1983 it entered the laboratory of the German company BASF, where the active ingredient of Stroby - kresoxim-methyl - was developed and synthesized. Effects and characteristics: Stroby is a bionic fungicide extracted from natural substances with protective, therapeutic, and eradicative effects. It has a novel mechanism of action and can serve as a new effective tool for integrated disease management and resistance management. Its pharmacological action targets the cytochrome complex, blocking the electron transport process in the mitochondrial respiratory chain of pathogens. Its mode of action is completely different from other known fungicides. It has protective activity and serves as both a therapeutic agent and an eradicant. Inhibiting spore invasion is one of the most important steps in preventing disease occurrence. Target pests and diseases: Stroby can be used on cucurbits, legumes, fruits, leafy vegetables, flowers, Chinese medicinal herbs, grain crops, and more to control powdery mildew, anthracnose, scab, rust, gummy stem blight, leaf spot, black spot, ring rot, spotted leaf fall, stem blight on fruits and leaves, and it also has excellent control effects on gray mold and early blight of plants. It is also effective against some lower fungi such as downy mildew and phytophthora blight. After spray treatment, the active ingredient is absorbed by the waxy epidermis of crop leaves and fruits, and because it has a deposition effect, it is resistant to rain washing. The active ingredient is slowly released in a diffusion form, providing a long duration of efficacy. The medication has translaminar movement and leaf surface penetration functions; if only one side has been treated, the active ingredient can penetrate through the leaf, and after a few hours the untreated leaf surface is equally effective. Usage methods: Stroby is an organic fungicide with a completely new mode of action and no cross-resistance with conventional medications. The spray interval is 10-14 days, and there is almost no residue after the pre-harvest interval. It is safe for natural enemies, suitable for integrated pest management, and complies with EPA standards. 40 mm of rainfall has almost no effect on its efficacy. Its active ingredient is a lipophilic substance that can be released over a longer period. The commonly used formulation of Stroby is a 50% dry suspension concentrate. Specific usage methods: when used as a protective agent, spray once every 10-14 days; when used as a therapeutic agent, spray once every 7-10 days. For conventional spraying, dilute 3000-4000 times with water for vegetables and 5000-7000 times for fruit trees; for orchid leaves, it is recommended to spray at a dilution of 2500-3500 times. Precautions: Under normal conditions, Stroby's efficacy is not affected by temperature, and it can be used on crops andorchidsat all growth stages. It can be used on wet leaves and can be mixed with other insecticides, fungicides, acaricides, plant growth regulators, and foliar fertilizers. Rotation and tank mixing are encouraged; do not use it consecutively. It is best to limit use to 3 to 5 times per year. Stroby has low toxicity to bees, beneficial mites, earthworms, and other beneficial organisms, and is relatively safe for the environment. After using Stroby, Yaoyuan felt that it had some effect in controllingorchidleaf blight and shrinkage with scorched tips on leaf surfaces, but note that it should be rotated and not used frequently. (Gao Haiyong)