Types of Common Herbicides

Simazine (CAS 122-34-9) is a highly efficient and selective herbicide of the triazine class, commonly used to control annual and perennial broadleaf weeds and most monocotyledonous weeds propagated by seeds in crops such as corn, sorghum, sugarcane, tea gardens, orchards, etc. It can also be used for non-selective weed control on railways, highways and oil fields. Simazine has significant effects on controlling weeds such as morning glory, barnyard grass, crabgrass, goosegrass, pigweed, purslane and amaranth. Structurally similar to Atrazine (CAS 1912-24-9), it inhibits photosynthesis.

Diuron is a systemic urea herbicide with some contact killing effects. It can replace other urea herbicides and is mainly used on crops such as cotton, soybeans, tomatoes, tobacco, strawberries, grapes, orchards and rubber plantations to control annual grass weeds like barnyardgrass, goosegrass, dogtail grass and amaranth. When absorbed by the roots or leaves of plants it inhibits photosynthesis causing leaf discoloration and loss of green color in the tips and edges. Diuron can be used at low doses for selective weed control through differential timing or at high doses as a non-selective herbicide.

Effects of Weather on Herbicides

Herbicides come in two types: liquid and granular. Liquid herbicide is best for controlling heavy weed growth, while granular herbicide is more effective for preventing weed growth during planting. Although the preventive effect of granular herbicide is not immediate, it lasts longer.

However, if herbicides are used on rainy days, the rain may dilute the concentration of the herbicide and even wash away the herbicide on weeds, resulting in a decrease in its effectiveness or inability to achieve weed control. If it is a liquid herbicide, it is best to spray it on a sunny day and let it dry for about 6 hours under sunlight. Spraying herbicides after rain is also a good time. When using granular herbicides, if it rained the day before and the ground is moist, the medicine will be more easily absorbed and have better effects.

Some growers may ask, “Should herbicides be reapplied after rainfall?”

To avoid crop damage, it’s not recommended to reapply herbicides in situations where rain may affect their concentration. Instead, wait for two or three days after the initial application to see if the weeds show signs of poisoning. If they do, no further spraying is necessary; if not, spraying can be done at a reduced concentration as needed. Additionally, it’s best to avoid direct spraying on crop seedlings during application.

Application of herbicide adjuvants

Adjuvants are crucial in enhancing herbicidal efficacy, crop safety, reducing herbicide dosage, minimizing environmental pollution and increasing economic benefits. They can be added to the spray solution through mixing tanks to affect various properties such as viscosity, sediment coverage area, physical form, water content, solubility and volatility. Additionally, adjuvants reduce surface tension of spray solutions which improves herbicide retention and wetting ability while also increasing diffusion capacity and rain fastness. Furthermore, they enhance resistance to photodegradation.

PINEYE™ EC emulsion is a new type of rain-resistant additive with environmentally friendly characteristics of bio-based products. It has similar lipophilic properties to oil, a wide range of molecular weights, and nonlinear molecular structures, which can increase the retention of the agent on plants that are difficult to wet.

PINEYE™ EC emulsion is an adjuvant emulsion made from biobased ingredients. It forms a flexible film on crop surfaces when applied one hour before rain, which slows down the penetration rate of rainwater into the cuticle layer. This prevents growers from having to reapply herbicides after rainy days, as excessive concentrations can cause phytotoxicity.

The sedimentation rate of PINEYE™ EC emulsion in performance testing is 6.6623 mg/cm2. When combined with herbicide during spraying, the pine resin polymer within the emulsion can expand the area covered by the herbicides on the ground surface. Within an hour of application, the emulsion dries and creates a flexible film that encases chemicals in microcapsules, safeguarding them from being washed away by rainwater or other additives.

PINEYE™ EC emulsion contains a bio-based polymer that is naturally beneficial to crops, flowers, and fruits. Its tested contact angle of 44.50° outperforms the organic-based competitor’s contact angle of 55.48°, making it a superior additive for dispersing purposes due to its better wetting effect.

PINEYE™ EC emulsion can form an elastic coating on crops, providing film-forming properties. This coating offers sun protection and anti-transpiration effects to prevent sunburn on fruits and vegetables.