Why should growers use adjuvants with pre-em herbicides?

Pre-emergent herbicides and adjuvants

As an early harvest comes to an end, growers’ attention will now turn to drilling winter cereals and OSR as soon as there has been enough rainfall and the soil holds sufficient moisture; but why should growers consider including an adjuvant such as Adhere with their pre-emergence herbicides? Using the information below, you can make an informed decision.

What is an adjuvant?

Typically used alongside crop protection products, adjuvants are designed to enhance spray efficacy. They can help by:

Reducing spray drift and ensuring even deposition over the target
Increasing coverage
Adhering products to the plant or soil surface, reducing run off
Slowing drying time to increase uptake
Reducing UV degradation

IntraCrop developed Adhere specifically as a partner to residual herbicides to optimise their efficacy.

What is Adhere?

Adhere is a unique, biodegradable, non-hazardous adjuvant for use with residual herbicides pre- and post-emergence. It contains a blend of fatty acid methyl esters combined with rosin and resin esters and emulsifiers, delivering strong adhesion and improved herbicide retention where it’s most needed.

How does Adhere work?

Adhere works by:

Reducing spay droplets under 100 microns decreasing spray drift and ensuring even deposition over the soil surface
Tackifiers (rosin and resin esters) bind herbicide to soil particles, reducing leaching
Keeps herbicide in the upper soil layer where weeds germinate, giving maximum control
Derived from renewable resources, it is less toxic to soil biota than paraffinic oil alternatives

What makes Adhere different?

Adhere represents a new classification of adjuvant. Its rosin and resin esters are low molecular weight compounds derived from pine resin that provide exceptional adhesion. With 98% renewable sourcing and a clean label, Adhere is a more sustainable choice for integrated weed management.

Adhere in grassweed management

The theory of marginal gains applies well to pre-emergence herbicide efficacy: seedbed preparation, application technology, product choice and weather all contribute. Adhere offers another gain, improving residual herbicide performance, especially under sub-optimal conditions.

How Has Adhere performed in trials?

Across 18 UK trials (2020–2025), adding Adhere (0.2 L/ha) to Luxinum® Plus + PDM + DFF consistently improved blackgrass control by an average of 4%.

In practice, a 4% improvement means:

8 fewer blackgrass heads/m² when the untreated background population is 200 heads/m²
Preventing ~800 seeds/m² from returning to the seedbank (each head producing ~100 seeds), reducing long-term weed pressure

Given that 97% control is needed in non-inversion tillage systems to prevent blackgrass populations from increasing, this improvement can be critical to sustainable management.

Why use Adhere?

Proven UK trial performance in increasing grassweed control
Improved crop safety under high rainfall conditions post-application
Biodegradable and derived from renewable resources
Simple to use. Apply at 0.2 L/ha, adding to the spray tank last