Common Poppy [Papaver rhoeas]

Poppy control is becoming increasingly difficult due to resistance to certain herbicides. That, along with a huge seed return where seeds remain viable in the soil for several years has seen an increase in Poppy populations across the UK.

Common poppy is an annual weed, ca. 20 – 80cm tall.

About the pest

About the weed

It is an upright, hairy annual 20-80cm tall. The stems are bristly and sometimes spreading. The dull green leaves at the base form a rosette with divided segments. The broken stem bleeds a white sap. The large flowers have four petals sometimes with a large black spot at the centre. The ovary is short and smooth.

Key features

Fruit: The seed head is short and smooth.

Biology

Common poppy occurs particularly in winter cereals and oilseed rape where it is competitive, but is also found in spring crops, fallows and more rarely vegetables and clover crops. Autumn-germinating seedlings can overwinter. Plants flower in midsummer, but there may be a second flush of flowers once the wheat crop has been harvested. The plant reproduces entirely by seed. The very long seed persistence means that poppy appears in newly cultivated land.

Symptoms & Diagnosis

Life Cycle

Seed longevity: Up to 100 years
Germination depth: 0.5 cm
Seed weight: 0.09 mg
Seeds/flower: 1360
Seeds/plant: 20000

Treatment

Management

The best control method is to stimulate germination through cultivation before spraying with glyphosate. Common poppy is controlled by a wide range of herbicides in cereals and legumes, but control is more difficult in brassicae crops. Sulfonylurea resistance has been confirmed in the UK.