Question: Are pesticides more effective under acidic or alkaline conditions?

Answer: Commonly used pesticide pH stability table is as follows :

• Paraquat: It is stable under the condition of pH value 3 and decomposes quickly under the alkaline medium.
• Glyphosate: Under acidic conditions, it is more stable than alkaline medium.
• Trichlorfon: Degradation time:510d (pH4)，46h (pH7), < 30min (pH9)
• 2，4-D Amine: More stable under acidic conditions.
• Chlorothalonil: More stable under acidic conditions, unstable in neutral and alkaline conditions.
• Benomyl: Degradation time:PH7, 1h; pH5-6, >30h.
• Chlorpyriphos: With the pH increasing, the degradation speed increases.
• Propargite: Degradation time:1h(pH9), 331h(pH6).
• Acephate: Degradation time:pH9 (16hrs), pH3 (710hrs), pH5 activity.
• Beta-cyfluthrin: Degradation time:25d(pH4); 11d(pH7); 5d(pH9).
• Bifenthrin: Stable under acidic media.
• Dimethoate:1.2d (pH9) Stable between pH 2-7.
• Endosulfan:In the acidic condition, it is more stable than the alkali condition.
• Chlorsulfuron: Stable under pH5.5-7 conditions.
• Chlorimuron-ethyl :More stable under pH5 conditions.
• Cypermethrin:Stability of drug efficacy between pH 3-5.
• Deltamethrin:Under the conditions of acidity, it is more stable than under the conditions of alkalinity.
• Ethephon: it's stable under<pH5.
• Rimsulfuron:Degradation time:0.3d(pH9),4.6d(pH5).
• acillus thuringiensis: pH4-7 stable; pH7 easy to decompose, pH>10 only 1h100% dissociation.

In summary, we can draw a conclusion that most pesticides are more stable under acidic conditions and have better results. The optimal pH condition range is 4-6.