Thiodiazole-copper is jointly developed by Longwan Pesticide Research Institute and Longwan Chemical CO., LTD., Wenzhou Zhejiang , P.R. China and granted the invention patent. LONGKEJUN is a kind of thiazole organic copper fungicide and highly effective, low-toxic, very safe, and commonly used to control bacterial leaf spot and leaf blight of rice, canker and scab of citrus.

Name and Property

Common name: thiodiazole-copper
Trade name: LONGKEJUN
Chemical name: 2-Amino-5-thiol-1,3,4-thiodiazole-copper
Expirical formula: C₄H₄N₆S₄Cu

Physical and chemical properties: The appearance of the technical grade is yellow-green powdery crystals. Its specific gravity and melting point are 1.94 and 300 centigrade respectively. It is indissoluble in water and most of organic solvents, and slightly dissolves in dim ethyl form amide. The appearance of the formulated product – LONGKEJUN 20% SC is yellow-green thick liquid with 1.16-1.20 of the specific gravity and 4-8μm of the fineness. Its pH value is 5.5-8.5 and suspensibility is greater than 90%. LONGKEJUN 20% SC is stable at the temperature of 54 ± 2 ℃ for 14 days or in 0 ℃ for 7 days. It is also very stable in the acid conditions but easily decomposes in strong alkalinity.

Product Characteristics

Highly effective and broad-spectrum: LONGKEJUN 20% SC is highly effective to both bacterial and fungus diseases.
Systemic and low toxicity: LONGKEJUN 20% SC is a very systemic and low-toxic fungicide.
Supper fine and good suspensibility: LONGKEJUN 20%SC is very fine with good suspensibility.
Prevention and Cure: LONGKEJUN 20% SC has both preventive and cured effects.
Application safety: LONGKEJUN 20% SC is safe to crops, fishes, birds, honeybee, silkworms, human beings, animals and beneficial insects. LONGKEJUN 20% SC is no pollution to the environment.
Special action mode: The thiazole group has special effect on bacteria and the ionic copper has a good control efficacy on fungi and bacterial.

Efficacy

LONGKEJUN 20% SC is widely used to control more than 60 kinds of bacterial and fungi diseases. The main target pests are follows.
Bacterial diseases: bacterial leaf spot and leaf blight of rice, root rot of rice plant, canker of citrus, canker of shaddock. Angular leaf spot of melon, angular leaf spot of legume, soft rot of cabbage.
Fungus diseases: scab of citrus, scab of shaddock, leaf spot of banana, leaf spot of Logan, leaf spot of peanut, wilt of watermelon, anthracnose, damping-off and ring rot of crops.

Toxicity

(1) Acute toxicity: The oral LD₅₀ of the technical grade to female rat is 2, 150mg/kg. The oral LD₅₀ of the formulated product to rat is greater than 5050mg/kg. The dermal LD₅₀ of the technical grade and the formulated product to rat is both greater than 2000mg/kg.
(2) No mutagenic effect to germinal cells has been observed in studies at different dosages of the technical grade.
(3) Ames test of the technical grade is negative.
(4) No mutagenic effect to micronucleus has been observed in studies at different dosages of the technical grade.
(5)The no effect level of the subchronic oral toxicity is 20.16mg/kg per day.
(6)Technical grade has no irritation to skin and slight to eye.
(7)The formulated product has slight irritation to skin and eye.
(8)The formulated product has slight sensitization to skin.

Action Mode

LONGKEJUN 20% SC has two active groups which show fungicidal effect. One is thiazole group, which has no inhibiting effect on bacteria outside of plants. It is presents highly effective inhibition inside the plant. The active ingredient of LONGKEJUN 20% SC taken up by the plant causes severe damage to bacteria and results in the cell skin of bacteria thinning to die. The other is copper ion, which has strong inhibiting effect both on fungi and bacteria. After exchanged with positive ions such as H, K on the cell surface of disease- producing germs, copper ions of product bring on protein of cell membrane curdled and killed germs. Some copper ions, penetrated into cell of disease-producing germs and combined with some kinds of enzyme, affect the energy of cells of disease-producing germs and result in enginery maladjustment. A s a result, the disease-producing germs die because of crock up. Under the combination action of those two active groups, LONGKEJUN 20% SC, in a word, can provide perfect fungicidal effect on different target.