Soybean field at sunset

Concentrated Disease Protection

January 15, 2024 5:00 p.m.

By Nufarm

Pythium disease prefers cold soil temperatures and excess soil moisture.  This disease can be extremely severe if excessive rainfall occurs immediately after planting and most active with soil temperatures between 59-62 degrees.  Seeds are infected prior to emergence but can continue to be infected once emerged above ground. Seedlings will likely yellow, wilt, and die due to damping-off. Upon examination, the seedlings reveal dark, slimy lesions on the roots. The outer tissue of the root is infected and may peel off, revealing a white stele.  

Phytophthora root and stem rot of soybean can occur when soil conditions are wet and the soil temperature is above 65 degrees. The disease is caused by a soilborne pathogen known as Phytophthora sojae. Symptoms can be observed as wilting of plants, root systems with dark lesions that may be rotted, dark stem lesions extending up from the soil line, and seedlings that have damped-off. Wet soil conditions are required for Phytophthora rot to be severe because the pathogen produces spores (zoospores) that must "swim" through the soil to infect soybean plants. The most severely affected areas in a field are generally those that tend to hold moisture for extended periods (low areas, areas with higher clay content, etc.). Infection can take place throughout the season and adult plants can be killed in severe conditions.  

Nufarm’s Precinct™ is a modern systemic seed treatment fungicide that offers excellent control of select diseases, such as downy mildew, Pythium spp., and Phytophthora spp. The product is quickly absorbed by the seed and spreads through the plant after germination, leading to uniform distribution within the plant and less leaching or loss due to soil binding. This protects the seed and the seedling at an early stage, resulting in fast development and a uniform crop. Precinct is effective in both damp colder conditions ideal for Pythium, and warmer humid conditions ideal for Phytophthora and downy mildew.

Precinct is specially developed for seed treatment and contains 4.1 lbs. of mefenoxam per gallon, the most active isomer of the compound metalaxyl, biologically. Generic metalaxyl seed treatment products include the presence of both the active molecule and the inactive molecules that will lead to competition to bind to the fungal pathogen, reducing the power of the chemistry required to provide plant protection against the pathogen.  Precinct provides a higher level of active molecules to target the pathogenic fungi of pythium, phytophthora, and potential downy mildew.

The loading of Precinct makes it the most concentrated mefenoxam seed treatment formulation on the market today. For example, in soybeans Precinct offers:

• 70% reduction in use rate vs. a 2.65 lb metalaxyl (0.75 fl oz/cwt vs 0.23 fl oz/cwt)

• 50% reduction in use rate vs. a 4.0 lb metalaxyl (0.50 fl oz/cwt vs 0.23 fl oz/cwt)

Precinct is a highly concentrated water-based formulation, which mixes easily with other products and water. This formulation reduces the amount of product to be transported, the storage space required, and the used packaging to be rinsed. Due to the low use rate of Precinct, it is important to apply the product as part of a seed treatment slurry or with a carrier, like colorant, seed treatment polymer, or water to ensure the distribution of the active across the entire seed volume.

One of the primary advantages of Precinct over standard metalaxyl formulations is the formulation stability and longevity. Being highly miscible and stable, Precinct is a great option for custom blend operations to improve the blend quality under variable storage conditions.

Labeled on more than 50 crops and compatible with most standard seed treatment formulations, Precinct offers optimum flexibility for operations treating multiple crops. Precinct also contributes to healthy early season growth by effectively controlling various soil and seed-borne fungi with a small quantity of active ingredient, so it has a very limited environmental impact. 

To learn more about Precinct™ visit