25% sulfur·carbendazim wettable powder, registered for only one target: rice blast, at 320–480 g/mu, by spraying.
This dosage is noteworthy—320–480 g/mu, which is among the higher per-mu application rates of all registered products.Although they are both carbendazim-based products, the control of rice blast typically uses 100–200 g/mu. Why does this one require 320–480 g?
The total content is only 25%.(total sulfur + carbendazim), half that of 50% carbendazim wettable powder.
The active ingredient content is low, so achieving the same effective field concentration requires a larger formulation dosage. 320–480 g ÷ 2 = 160–240 g (equivalent to the dosage of a 50% formulation), which aligns with the application rates of other carbendazim products.
This is a simple conversion issue, not a special formulation.
SulfurInorganic sulfur-based protectant fungicides interfere with pathogen metabolism at multiple sites in a non-specific manner. They rarely induce resistance and also possess acaricidal activity.
Carbendazim: A systemic therapeutic agent of the benzimidazole class, it interferes with the formation of the spindle apparatus during mitotic division of the pathogen.
The logic of the combination: sulfur establishes a barrier on the surface and dilutes resistance pressure, while carbendazim acts on mycelium that has already invaded the tissue.
However, it should be noted that at a total content of 25%, the respective proportions of the two components are both relatively low.This formulation is positioned more toward routine protection combined with mild curative activity., rather than intensive treatment.
Rice blast, caused by Pyricularia oryzae, is one of the most important diseases of rice.
Two key stages请提供需要翻译的中文段落。
Leaf blastAround the tillering stage, spindle-shaped lesions appear on the leaves (grayish-white centers with brown margins). In severe cases of leaf blast, leaves wither and die, impairing photosynthesis.
Rice neck blastAt the heading stage, the pathogen infects the neck of the panicle (the junction between the panicle and the stem), causing white heads and shriveled grains.Once neck blast occurs, it is basically impossible to remedy.This is the primary form of yield loss caused by rice blast.
Prevention and control window请提供需要翻译的中文段落。
Leaf blast: at the early stage of disease onset (when lesions first appear in the field)
- Neck blast:3-5 days before the booting stageThis is the most critical pass.
The expression "early stage of disease onset" needs to be understood separately for rice blast.The "early stage" of leaf blast refers to the early phase when visible lesions appear; the "early stage" of neck blast actually occurs before symptoms manifest (at the boot-splitting stage)—once white heads are observed, it is already too late.
Application rate range: 320–480 g/mu, a span of 50%. Adjustment basis:
320 gWhen the disease is mild, prevention is the main approach, and plants are relatively small.
480 gramsDuring the rising phase of disease incidence, at the critical stage for controlling rice neck blast, and when plant density is high.
For this application against rice neck blast, it is recommended to use the upper limit (480 g/mu).Reason: The pesticide deposition on the panicle neck is inherently lower than that on the leaves (the panicle has a small surface area, and by the time of spraying, the rice plants are already tall, making it difficult for the spray to reach the target), thus requiring a higher concentration for compensation.
Water volumeRice spraying typically uses 30–45 kg of water per mu. For the application targeting rice neck blast, an adequate water volume is essential to ensure that the spray solution reaches the neck node of the panicle.
Plant part请提供需要翻译的中文段落。
- Leaf blast: entire plant leaves, with emphasis on new leaves.
- Neck blast:Panicle and panicle neckWhen spraying, the nozzles should be directed upward or horizontally, and should not only be swept downward.
Both the upper and lower surfaces of rice leaves should be sprayed.Rice blast infects through stomata and the epidermis; spraying the abaxial leaf surface is equally important.
Registration: once every 7-10 days.
This interval is shorter than the 10–15 days for carbendazim alone. The reason is the relatively short residual activity of the sulfur component—the spray film formed by sulfur on the leaf surface is washed off by rain and degraded by ultraviolet light, with 7–10 days being the practical duration for maintaining protection.
Rice paddies have high humidity and frequent rainfall.Sulfur has a faster loss of residual efficacy, so the application interval should be shortened.
Temperature is a risk factor for sulfur.Applying pesticides when the temperature exceeds 30°C may easily cause phytotoxicity. For rice pest control during the high-temperature summer period, pesticide application should be scheduled in the early morning or late afternoon.
Do not mix with mineral oils or certain organophosphorus pesticides.(Mixing sulfur with these may cause phytotoxicity.)
Carbendazim should not be mixed with copper-based formulations or strongly alkaline pesticides.
Some rice varieties are sensitive to sulfur.For first-time use, small-area trial spraying is recommended.
Pre-harvest interval: 30 days; maximum 3 applications per season.Rice is a food crop, and the 30-day interval requirement means that the last pesticide application must be completed more than 30 days before harvest.
It typically takes 30–45 days from the booting stage to harvest in rice. If the final spray is applied at the booting stage (for control of neck blast), the interval to harvest falls right at the edge of 30 days.Therefore, the timing of this application must be calculated accurately — it is better to apply earlier than later.
Three applications: one at the leaf blast stage, one at the boot-breaking stage, and if disease conditions warrant, one supplementary application at the early grain-filling stage.
The precautions state that it "cannot be mixed with substances such as copper, mercury, and alkaline pesticides."Tank mixing or sequential application请提供需要翻译的中文段落内容。
The four characters "前后连续使用" (used consecutively before and after) are easily overlooked. Their meaning is:After applying copper-based fungicides (such as copper hydroxide) or alkaline agents (such as Bordeaux mixture), do not immediately apply this product.Please provide the Chinese paragraph you would like me to translate.
The reason is that copper ions and alkaline substances remaining on equipment and leaf surfaces can react with carbendazim and sulfur, resulting in reduced efficacy or even phytotoxicity.
In practice,If a copper-based formulation was applied the previous day, do not apply this product the next day; allow an interval of at least 3–5 days.
Apply pesticides in the early morning and evening when temperatures are high.This point addresses the sulfur component — the risk of sulfur phytotoxicity increases at high temperatures.
Avoid direct entry of the spray solution into fish ponds and other water bodies.Sulfur is toxic to aquatic organisms.
Incineration and deep burial of packaging materialsand must not be discarded at will or used for other purposes.
Pregnant and lactating women must avoid contact.
