50% Sulfur·Thiophanate-methyl suspension concentrate, registered for cucumber anthracnose, 150-300 mL/mu, spray.
The dosage range spans a twofold difference, and the source of this flexibility isPlant growth incrementIt is not a disease condition.
I. Formulation Positioning
Sulfur(Inorganic sulfur multi-site protection): Interferes with electron transport in redox systems, with virtually no resistance, and also provides acaricidal activity.
Thiophanate-methyl(Benzimidazole systemic): Converted in vivo to carbendazim, inhibiting spindle formation.
Product performance: "A partially systemic fungicide with a relatively long residual effect, possessing both protective and curative action."
The expression "partially systemic" is very accurate.The systemic action comes from thiophanate-methyl, while sulfur remains only on the surface.
II. Characteristics of cucumber anthracnose
SymptomsNearly circular lesions appear on the leaves, with brown margins, grayish-white centers, and concentric rings; sunken lesions form on the fruit, and pinkish viscous spore masses are produced under humid conditions.
Occurrence conditions请提供需要翻译的中文段落。
High temperature and high humidity (25–28°C, relative humidity above 90%)
Disease incidence is more severe under protected cultivation (high humidity and poor ventilation inside the greenhouse).
Transmission routesThe pathogen overwinters as mycelium or conidia in diseased plant residues and is spread by rain, irrigation water, and farming operations.
III. Why is the range of 150–300 mL/mu so wide?
This interval does not correspond to disease severity, but rather to the plant growth stage:
From seedling stage to early flowering stageFor small plants with a low leaf area index, use about 150 mL.
Peak fruiting stageThe plants are tall, and the leaf area index can reach 3–4 (for greenhouse cucumbers). With multiple overlapping layers of leaves, 300 mL is required to achieve adequate coverage.
This logic applies to all vegetable fungicides.The dosage per mu varies with plant growth rather than being a fixed value. A fixed dosage may result in waste at the seedling stage and prove insufficient during the peak growth stage.
IV. Water Volume Is Key
The registration does not specify the exact water volume, but the conventional water volume per mu for cucumber spraying is45-60 kg(Greenhouse cucumbers can reach 60-75 kg).
Why do cucumbers require so much water?
Large leaves and a high leaf count.
- Tall plants (can reach over 2 meters under trellis cultivation)
The leaves are stacked in multiple layers, so an adequate water volume is essential to "carry" the spray solution down to the lower and inner canopy.
Typical consequences of insufficient water supply: Only the upper leaves are sprayed, while the lower and inner canopy leaves are missed, yet anthracnose is precisely prone to occur in these high-humidity areas.
V. "Spray both the upper and lower leaf surfaces."
Registration particularly emphasizes this point.
Anthracnose infects through stomata and the epidermis.The high stomatal density and humidity on the leaf underside make it the primary entry point for infection. Spraying only the upper leaf surface leaves half the plant unprotected.
Spraying techniquesAdjust the nozzle angle: sweep once from bottom to top (to cover the underside of leaves), then make a supplementary pass from top to bottom (to cover the upper surface of leaves).
6. 7-10 day interval
It is shorter than the 10–15 days of carbendazim. The reason is thatThe residual efficacy of sulfur is greatly affected by environmental conditions.请提供需要翻译的中文段落。
Sulfur film loss due to rain washout
High humidity inside the greenhouse may cause the pesticide film to be dissolved.
New leaves continue to unfold and require protective supplementation.
7. Compatibility of Sulfur with Thiophanate-Methyl
The mixture of these two components is feasible, but there are two points to note:
TemperatureRisk of high-temperature phytotoxicity from sulfur. The temperature inside the cucumber greenhouse may exceed 30°C.Pesticide application should be carried out in the morning or evening., avoiding the high temperatures at noon.
AlkalineThiophanate-methyl decomposes under alkaline conditions. Sulfur itself is slightly acidic, and the two components are compatible, but they must not be mixed with alkaline pesticides (such as Bordeaux mixture).
VIII. Mixing and Other Precautions
Do not mix with mineral oils.(Sulfur + mineral oil = phytotoxicity).
Do not mix with copper-containing formulations.请提供需要翻译的中文段落内容。
Shake well before use.First, dilute it into a stock solution.
Two-stage dilution for pesticide preparation请提供需要翻译的中文段落。
Some cucumber varieties are sensitive to sulfur.(Especially at the seedling stage), a small-scale trial spray is recommended for first-time use.
9. 4-day interval, 2 times per season
Pre-harvest interval: 4 days; maximum 2 applications per season.
Four days is one of the shortest pre-harvest intervals among all registered products.This makes it highly suitable for continuously harvested crops such as cucumber — harvesting can begin just 4 days after application.
But the upper limit of 2 times.This limits the frequency of use. The pesticide must be rotated after two applications.
10. Do not use consecutively with copper-based formulations.
Note: This product must not be mixed or used with copper-based formulations.Continuous use in succession.请提供需要翻译的中文段落内容。
Copper-based fungicides (copper hydroxide) are commonly used on cucumbers to control bacterial angular leaf spot. After applying copper-based products, this product should not be sprayed immediately; an interval (generally 3–5 days) is required.
CausesCopper ion residues + thiophanate-methyl (decomposes under alkaline conditions) = reduced efficacy.
11. Apply pesticides in the morning and evening during high temperatures.
To prevent phytotoxicity, pesticides should be applied in the early morning or late afternoon during seasons with higher temperatures.
The temperature inside the cucumber greenhouse may exceed 30°C, and the risk of sulfur phytotoxicity increases under high temperatures.Apply pesticides in the morning or evening.Avoid midday.
12. Secondary Control Effects and Risks of Sulfur
Sulfur exhibits activity against both spider mites and powdery mildew, two common problems on cucumber, demonstrating clear value for simultaneous control of both pests.
At the same time, attention should be paid to the impact of sulfur on natural enemies, as well as the potential for frequent applications to induce spider mite resurgence.
13. Other Safety Precautions
Wear protective equipment and gloves.
Do not smoke, eat, or drink beverages during application. After work, wash hands and exposed skin.
Avoid contaminating water sources. Burn or bury packaging deeply.
Pregnant and lactating women must avoid contact.
It is recommended to rotate with fungicides having different modes of action to delay the development of resistance.