How to Identify Fake and Substandard Pesticides: A Practical Guide for Agricultural Production
What are fake and substandard pesticides?
1. The following pesticides are fake pesticides: (1) those that use non-pesticides to pass off as pesticides, or use one type of pesticide to pass off as another type of pesticide; (2) those whose types and names of active ingredients do not match the types and names of the pesticide active ingredients stated on the product label or instructions.
2. The following pesticides are substandard pesticides: (1) those that do not meet pesticide product quality standards; (2) those that have lost their efficacy; (3) those mixed with harmful components that cause phytotoxicity or other harm.
How to identify whether pesticides are genuine or fake?
1. Inquiry of registration certificate numbers: (1) Log on to the "China Pesticide Information Network", click on the online inquiry system, and enter the registration certificate number to find out whether the registration certificate number is authentic and to access the electronic version of the label filed with the Ministry of Agriculture; (2) Search the "Compilation of Pesticide Management Information";
In addition to label verification and instrument testing, whether a pesticide product is genuine, that is, qualified, or fake and substandard, that is, unqualified, can be identified by visual inspection through the following two intuitive and simple methods:
2. Identification from the physical form of the pesticide
(1) Observation of physical form
(1) Powders and wettable powders should be loose powder without lumps. If there is caking or a noticeably granular feel, it indicates that the product has absorbed moisture; not only does the fineness of the product fail to meet requirements, but the content of its active ingredients may also have changed. If the product color is uneven, this also indicates that there may be quality problems.
(2) Emulsifiable concentrates should be homogeneous liquids, with no deep sediment or suspended matter. If layering and turbidity occur, or if the emulsion after dilution with water is uneven or has floating oil or sediment, this all indicates that the product quality may have problems.
(3) Suspension concentrates and suspoemulsions should be flowable suspensions without caking. After long-term storage, layering may occur, but after shaking they should be able to return to their original state. If after shaking the product cannot return to its original state or still has caking, this indicates that the product has quality problems.
(4) If tablets used for fumigation have turned into powder, this indicates that they have lost efficacy.
(5) Aqueous solutions should be homogeneous liquids, with no sediment or suspended matter, and generally should not show turbidity or sediment after dilution with water.
(6) Granule products should be uniform in particle size and should not contain much powder.
(2) Examination of physical and chemical properties
(1) Wettable powder: Take a transparent glass bottle and fill it with water, wait until the water surface is still, take half a spoonful of the pesticide, and pour it into the water at one time from a height of 1-2 cm above the water surface. A qualified wettable powder should be able to gradually wet and disperse in the water relatively quickly, and the total wetting time generally will not exceed 2 minutes. An excellent wettable powder, after being put into water, can form a relatively good suspension without stirring. If the bottle is shaken evenly and left to stand for 1 hour, there should be relatively little solid sediment at the bottom.
(2) Emulsifiable concentrate: Fill a transparent glass with water, use a dropper or glass rod to transfer the sample, and drop it onto the still water surface. A qualified emulsifiable concentrate (or one with good emulsifying performance) should quickly spread downward and outward, and after slight stirring form a white milk-like emulsion. After standing for half an hour, there should be no visible oil droplets or sediment.
(3) Water-soluble emulsifiable concentrate: It can dissolve mutually with water and does not form a milky white color.
(4) Dry suspension concentrate: After dilution with water, it can disperse spontaneously, and the technical material disperses in the water as particles with a diameter of 1-5 micrometers, forming a relatively stable suspension.