Cereal PGRs

Cereal plant growth regulators (PGRs) are often likened to an insurance policy for your crop, reducing the risk of lodging and the subsequent, potentially devastating yield, quality and time losses.

Some PGRs such as Canopy and Medax Max have also been proven to enhance rooting.

Three key lodging risk factors

Crop variety: Varieties with a resistance to lodging score of 7 or less on the AHDB Recommended List should be considered at risk of lodging.

Yield potential: A higher yielding crop will produce heavier ears, putting greater weight on the stem and increasing the lodging risk. For winter wheat, it has been estimated that each tonne per hectare above 9 t/ha, reduces the resistance to lodging score by 0.5 points.

Spring canopy size: Sowing date, establishment, available nitrogen and over winter temperatures all affect the size of the crop canopy and can be measured by its Green Area Index (GAI), the amount of green tissue per m2 of ground.

Winter cereals lodging risk

Expanding on the lodging risk factors outlined above, ADAS’ Winter Cereal Lodging Model looked at factors influencing lodging resistance scores and found that for every week winter cereals are sown earlier, the variety lodging resistance score is reduced by 0.5 points. Ultimately, earlier drilled crops are thicker with higher yield potential and require robust PGR management.

Robust, multi-active PGRs such as Canopy and Medax Max contain two complementary active ingredients for improved speed of uptake and more consistent results, along with benefits beyond height reduction

Canopy rate reminder

Avoiding lodging and brackling in spring barley

Lodging in spring barley has become more common in recent years, driven by increased yields and moderate to low lodging resistance scores.

Early severe lodging can reduce yield by up to 50% and even late brackling has been shown in ADAS trials to reduce yield by up to 1.4 t/ha.

Based on recent trials, ADAS have put together a comprehensive guide to help assess and manage lodging risk in spring barley.

Spring barley lodging guide

Spring barley lodging calculator

ADAS have also produced a simple, spring barley lodging calculator to help assess spring barley lodging risk, after adjusting for crop management.

Canopy, Medax Max and Terpal are all robust and chlormequat-free PGR options for use in spring barley.

Spring barley lodging calculator

PGRs in spring oats

Our Agronomy Manager, Andrew Clune had the pleasure to present an overview of PGRs as part of AHDB’s spring oat forum webinar in January 2022.

Andrew’s presentation on PGRs in spring oats can be seen from 59:00 in the webinar.

AHDB oats webinar

Dr Pete Berry discusses when to apply PGRs and the main benefits they offer.

How to get the most out of your PGR application

PGRs act by inhibiting cell growth making the plant shorter. PGRs work best when the crop is actively growing, although Canopy and Medax Max will work at lower temperatures due to benefits of combined active ingredients

To manage growth throughout the plant's entire lifecycle, a split dose, up to GS30 and GS31-32 will bring better results and if there is a high lodging risk, any applications may have to be followed up at GS37-39.

Scroll through the below images for more information on when to apply a reliable and flexible PGR such as Canopy or Medax Max, and the benefits they offer.

Canopy® is a plant growth regulator for reduction of crop height, which can lead to lodging control and yield protection in all varieties of winter wheat, winter and spring barley, winter and spring oats, winter rye and winter triticale.

Medax® Max is a plant growth regulator for the reduction of crop height which can lead to the control of lodging in winter and spring wheat, durum wheat, winter and spring barley, winter and spring oats, winter rye and winter triticale.

A plant growth regulator for late season use in winter wheat, winter and spring barley, triticale and winter rye. Terpal® is the tried and tested industry standard, delivering stem and root lodging resistance, and is an invaluable tool for protecting yield and quality.