Today we are talking to Agrii's Mark Glover, product manager for biologicals, adjuvants and micronutrition and Tim Horton, technical manager for combinable crops.

Today we’re going to focus in on OSR and examine some of the early season challenges with some novel solutions.

Early Season Challenges and Solutions for Oilseed Rape: Expert Insights

What are the early season issues affecting oilseed rape crops?

Tim Horton, Technical Manager for Combinable Crops:
This year, crops emerged during warm weather after the August bank holiday, leading to high pressure from cabbage stem flea beetle adults. This caused significant issues with crop establishment. We aim to create a resilient crop capable of withstanding seasonal pressures and supporting viable yields.

How does this season compare with the past 2-3 years?

Tim Horton:
Flea beetle pressure varies annually. While some years have seen lower numbers, there were seasons with exceptionally high levels, making crop establishment a major challenge. High pressure often coincides with late August to early September when temperatures increase, triggering adult beetle activity.

How does stress affect a crop's susceptibility to flea beetle?

Tim Horton:
Cabbage stem flea beetles are more attracted to stressed crops. Reducing plant stress can minimise damage, allowing the crop to establish more robustly. Healthy, unstressed plants are better equipped to grow rapidly and withstand beetle damage.

What are the key stages of cabbage stem flea beetle attack?

Tim Horton:
There are two main stages of susceptibility: during crop establishment (up to the two-leaf stage) when adults can cause significant damage, and later when larvae enter leaf petioles and move into the main stem, restricting yield potential.

What agronomic approaches should be taken to combat early season challenges?

Tim Horton:
Developing a strong root system is essential. The focus should be on solutions that support quick establishment and reduce stress. This helps mitigate the impact of adult damage and enhances overall crop resilience.

What solutions can be applied to support oilseed rape growth?

Mark Glover, Product Manager for Biological Adjuvants and Micronutrients:
Some products in our portfolio, like Nutriphyte PGA, have proven efficacy over time. These products aid in developing a robust root system and healthy crop growth. Nutriphyte PGA, for instance, helps load the plant with phosphate, enabling quicker growth in spring when natural phosphate availability is limited at temperatures below 7°C.

What can be done if the crop structure limits leaf uptake?

Mark Glover:
If foliar uptake is limited, products like Quark, a unique formulation of zinc with nitrogen, can be used to enhance root development through root uptake. Quark promotes root structure without directly impacting nitrogen utilisation or carbon fixation.

When should specific products be applied to maximise effectiveness?

Tim Horton:
A programmed approach ensures the plant is strong throughout different growth stages. Nutriphyte PGA can be used at the cotyledon stage to reduce stress, and subsequent applications can be made to enhance phosphate levels and build resilience as the plant moves into winter and spring.

What are the key differences between products in the Agrii portfolio?

Mark Glover:
Each product serves a unique purpose. Nutriphyte PGA contains specific isomers that optimise plant growth by improving phosphate availability and carbon fixation. Quark, on the other hand, is a zinc acetate formulation that boosts root development. PhysioN is composed of amino acids and methylated urea, which help reduce plant stress and support protein synthesis.

How do you decide which products to apply?

Tim Horton:
The choice depends on factors such as whether seedbed fertiliser was applied. If nutrients were placed with the seed, using products to stimulate root growth can help access those nutrients. If nutrient application was minimal, PhysioN, which reduces stress and supports growth, could be more beneficial.

What are the returns on investment for applying these products?

Mark Glover:
Investing in these products can save a crop. For example, a neighbour's well-established crop last year thrived until winter but was lost due to poor rooting. Ensuring a modest investment in crop support can prevent significant losses and is worthwhile.

How important is timeliness in applying these products?

Tim Horton:
Timeliness is crucial during early establishment. A viable crop must have a strong canopy and stem to withstand larval stages. Applications to build resilience can be made over time, but early interventions are key to getting the crop established.

What patterns have emerged over the past few years regarding flea beetle pressure?

Tim Horton:
High temperatures and low soil moisture in early September often signal high flea beetle pressure. Crops emerging during these conditions are most at risk. Early drilled crops that established well and maintained moisture fared better and were less stressed.

How should farmers approach oilseed rape management each season?

Mark Glover:
Each season presents unique challenges. For example, this year in Hampshire, early-drilled crops benefited from moisture but became top-heavy after a dry spell, highlighting the importance of promoting root development even in well-established crops.

What key messages should listeners take away?

Mark Glover:
Assess the current stage of your crop and anticipate future challenges, such as cabbage stem flea beetle. Focus on achieving an unstressed, well-rooted, well-established crop to mitigate risks.

Tim Horton:
For this year's crop, resilience is key. Ensure plants are strong enough to withstand larval damage and remain viable throughout the season.

Read an article from Agrii's David Leaper, Seed Technical Manager, on an Eight Point Plan for Managing Cabbage Stem Flea Beetle here.