The Excellent Fungicide – Metalaxyl from Heben

Feb 15, 2023

The most important acyl alanine is the fungicide metalaxyl. Metalaxyl is a phenyl amide fungicide developed by Syngenta in Switzerland and listed in 1977. In China, it was developed and produced by Zhejiang Heben in 1995s. Here we briefly review it in registration, market, function, etc.

What is Metalaxyl?

Metalaxyl is a fungicide that is used to control a wide variety of diseases in crops. It works by inhibiting the growth of fungi, bacteria, and other pathogens. Metalaxyl is typically applied as a foliar spray, but it can also be applied through irrigation systems.

Metalaxyl is a safe and effective fungicide that has been used for many years. It is relatively non-toxic to mammals and birds, and it poses minimal risk to the environment.

Fine Our Technicals

Structure and Chirality

Methyl N-(methoxyacetyl)-N-(2,6-xylyl)-DL-alaninate is an alanine derivative that is methyl alaninate in which one of the hydrogens attached to the nitrogen is substituted by a methoxyacetyl group, while the other is substituted by a 2,6-dimethylphenyl group. It is an alanine derivative, an aromatic amide, a carboxamide, an ether, and a methyl ester.

There is only one chiral carbon in the molecular structure, see figure 1, which makes it have two isomers, namely R-isomer, and S-isomer. Metalaxyl is composed of 50% R-isomer and 50% S-isomer while Metalxyl-M is composed of more than 92% R-isomer. And R-isomer is considered an active ingredient. So metalaxyl-M’s activity is much stronger than metalaxyl.

Figure 1 Molecular structure of Metalaxyl and its chiral carbon
Figure 1 Molecular structure of Metalaxyl and its chiral carbon

Mode of action

Metalaxyl is an organic compound that’s used as a fungicide. It works by interfering with the biosynthesis of ergosterol, which is a major component of fungal cell membranes. As a result, it inhibits the growth of fungi. Metalaxyl can be absorbed by the plant through the leaves, stem, and roots. It also inhibits protein synthesis in fungi by interfering with the synthesis of ribosomal RNA.


Metalaxyl was first registered as a pesticide in the U.S. in 1979, now it has successfully registered nearly all over the world, including the EU, China, India, Brazil, Austria, Russia, etc. And this product is applied in over 150 countries. As one of the biggest suppliers, Heben has a capacity of 2500 tons of metalaxyl and also has registered in many countries. Furthermore, we have 18 ICAMAs related to metalaxyl in China, see the below table 1:

Table 1. ICAMAs relate to metalaxyl and metalaxyl-m from Heben

Products Name ICAMA No. Expiration date
Metalaxyl TC PD20080910 2023/7/14
Metalaxyl 35%DS PD20081579 2023/11/12
Metalaxyl 10% + Mancozeb 48% PD20070444 2027/11/19
Metalaxyl 14% + Thiram32%+ Isoprothiolane4% WP PD20090539 2024/1/13
Metalaxyl 15% + Propamocarb HCL 10%WP PD20092773 2024/3/4
Metalaxyl 8% + Chlorothalonil 64% WP PD20085842 2023/12/29
Metalaxyl 8% + Mancozeb 64% PD20086169 2023/12/30
Metalaxyl 150g/L + Propamocarb HCL 150g/L SC EX20220136 2027/8/30
Metalaxyl 25%WP EX20210104 2026/9/28
Metalaxyl 50%WG EX20220222 2027/12/19
Metalaxyl 50%WP EX20220217 2027/12/19
Metalaxyl-M TC PD20094902 2024/4/13
Metalaxyl-M 350g/L ES PD20200228 2025/4/15
Metalaxyl-M 10g/L + Fludioxonil 25g/L FS PD20181189 2025/3/15
Metalaxyl-M 5% + Copper oxychloride 40%WP PD20140444 2024/2/25
Metalaxyl-M 5%+ Hymexazol 25% SL PD20150015 2025/1/4
Metalaxyl-M12.7% + Cyazofamid7.2%SC PD20220232 2027/10/8
Thiamethoxam 22.2%+Metalaxyl-M1.7%+ Fludioxonil1.1% FS PD20184134 2023/9/25


Which disease Metalaxyl can apply

Metalaxyl can be used to prevent and treat a variety of diseases, including downy mildew, Pythium, and Phytophthora. It is most commonly used on vegetables, fruits, and ornamentals.

Downy mildew

Downy mildew is a type of fungal disease that can affect a wide range of plants. It is most commonly found on leaves, but it can also affect stems, flowers, and fruits. Downy mildew is caused by several different fungi, but the most common is Pseudoperonospora cubensis.

Figure 2 Cucumber downy mildew
Figure 2 Cucumber downy mildew

If you have downy mildew on your plants, you can use Metalaxyl to treat it. Simply use Metalaxyl 25% WP 750x liquid spray that should be applied once every 10-14 days and no more than 3 times per quarter. Be sure to apply Metalaxyl early in the season, before downy mildew has a chance to take hold. Besides 35% metalaxyl DS can be used to prevent Millet downy mildew by mixing 200-300g with every 100kg of seeds.

Figure 3 Millet downy mildew
Figure 3 Millet downy mildew

Tobacco black shank

The black shank of tobacco is a devastating root rot disease caused by the oomycete pathogen Phytophthora nicotianae. Above-ground symptoms of this disease include wilting and yellowing of leaves, as well as dark brown to black areas at the base of the stem. Products formulated by metalaxyl are good solutions for controlling the Black shank of tobacco. When 2-3 days after sowing tobacco, spraying 25% Metalaxyl WP 133g per mu to the soil surface, then 7 days after transplanting, spraying 58%Metalaxyl+MancozebWP 500 times dilution per mu could prevent Tobacco black shank.

Potato Late blight

Late blight of potatoes is caused by a fungus known as Phytophthora infestans, the blight symptoms are found in both potato stem and tuber. The blight is also found in potato leaves. On leaves, late blight symptoms emerge as irregularly shaped dark dots that expand as the illness progresses.

Use 25% Metalaxyl WP 500 times liquid spray per mu of land, spray once every 10-14 days, up to 3 times.

Figure 4 Potato late bligh
Figure 4 Potato late bligh

Precautions while using Metalaxyl

When using Metalaxyl, it is important to follow the directions and take the necessary precautions to ensure your safety. Wear gloves while handling Metalaxyl and avoid contact with skin or eyes. If contact does occur, flush the area with water for 15 minutes. Do not inhale the product and keep it away from children.

Metalaxyl is quite a water-soluble and is translocated readily from roots to the aerial parts of most plants, but its lateral translocation is slight. Because the use of metalaxyl has already resulted in the appearance of strains resistant to it in some pathogens, it is recommended that it be used in combination with other, broad-spectrum fungicides.


If you’re looking for the best Metalaxyl products or any other agrochemical needs, Heben is the perfect solution. Give us a call at 86 (0)577 55882935 or email us at to request free samples today