Lowering lodging risk and PGR benefits

Lowering Lodging Risk

Root lodging caused by loss of anchorage of crown roots in the soil is the most damaging and prevalent type of lodging in the UK, often occurring during very wet periods in early summer. Whilst stem lodging often occurs closer to harvest when stem strength can reduce by up to 50% during grain fill in the ear. Good agronomic practices e.g. later drilling date and lower seed rates help produce stronger roots and better anchorage to protect against root lodging, alongside using PGRs which can be vital to prevent stem lodging and help against root lodging as well.

Modes of Action

Gibberellins (natural plant growth hormones) are produced at the nodes to initiate cell elongation below the growing point and PGRs such as chlormequat, prohexadione and trinexapac all act by inhibiting the biosynthesis of gibberellin, whereas ethephon breaks down ethylene to inhibit elongation. Later PGRs applied from GS37 work to shorten and strengthen the upper internodes. PGRs are an integral part of effectively managing lodging risk and growers should carefully monitor crop growth stage to ensure accurate timing application.

PGR Benefits Include;

• Quick, safe and reliable activity
• Shorten and strengthen lower internodes
• Stem thickening, even tillering and improved rooting
• Shorten upper internodes to prevent stem lodging and reduce brackling

The Potential Implications of Lodging 

Reduced yield, lower quality, and increased combining and drying costs, with economic loss greatest when crops lodge early in the season. On average 20% of the UK wheat area is lost to lodging every 3-4 years. In severe cases between 50-75% of field yield can be lost if crops lodge at ear emergence. Later lodging has less effect on yield but will impair quality e.g. Hagberg falling number and often causes harvesting delays which reduce farm profitability.

Make sure to assess lodging risk in your crops this spring! Watch out for wet or waterlogged soils which would put a high proportion of crops at risk of stem or root lodging and ensure crops are assessed for lodging risk routinely every year, so at risk crops can receive careful management early enough to protect yield and quality.

PGR Application Timing Programme

Chlormequat-based products can provide the cornerstone of early PGR programmes around the GS31/GS32 timing, and a platform for PGR application in mid and later timings. If using a split-dose timing, Clayton Proud® can be applied from an early GS32 timing.

Mid to late application timing (GS37 onwards) e.g. Tephon®, Clayton Proud® or prohexadione-based PGRs

This flexible application window targets the shortening and strengthening of upper internodes to prevent stem lodging, protect yield & quality, and reduce ‘brackling’ in barley to improve harvest efficiency.

Preventing or suppressing lodging during the vital later ‘crop heading’ stage allows optimum fertiliser use for maximum yields, and lodging control may be enhanced by using an approved chlormequat product earlier followed by later applied ethephon-based PGRs.