![](https://images.ctfassets.net/l2hapltrg3cz/4PfsZOELhQGHT1FHZrf9l/534cf12c38c81ac04d5611bd39af948d/volunteer_osr_01.jpg?fm=webp&w=1080&q=85)
Volunteer oilseed rape
Brassica napus
Importance
A problem wherever oilseed rape is grown. Can be difficult to control in many situations, especially in vegetable brassicas.
![](https://images.ctfassets.net/l2hapltrg3cz/6Hjh69FbBPhS2hNGcdcdsW/e65d94375aa7c50b6a83e778437c4c0e/volunteer_osr_01.jpg?fm=webp&w=1920&q=85)
1. Kidney-shaped cotyledons usually blue-green in colour, often with a reddish or purplish tinge.
![](https://images.ctfassets.net/l2hapltrg3cz/4JVRpyTzU833SVdSNcGaqQ/9d7e6f34136950a32e8987b2c8a58212/volunteer_osr_02.jpg?fm=webp&w=1920&q=85)
2. First leaves oval in shape with shallow indentations along edges. Later leaves are waxy and long and increasingly notched or irregular.
![](https://images.ctfassets.net/l2hapltrg3cz/1H7g4OafrPwPJS24wNH8wQ/8be283f125c66937ac4c7a039ab08183/volunteer_osr_03.jpg?fm=webp&w=1920&q=85)
3. Mature plant very familiar, particularly when in flower.
![](https://images.ctfassets.net/l2hapltrg3cz/1h0qvud54Zy9GzLekPOd5R/677728ff5c36c4492f44e69e75b97e83/FieldMate_Promo_Mobile.jpg?fm=webp&w=3840&q=85)
![](https://images.ctfassets.net/l2hapltrg3cz/3CvKagUshwoSyxEDqRj52c/bd6e3be09e808d22cf4c4c324b6d4ac7/FieldMate_Promo_Desktop.jpg?fm=webp&w=3840&q=85)
![](https://images.ctfassets.net/l2hapltrg3cz/3CvKagUshwoSyxEDqRj52c/bd6e3be09e808d22cf4c4c324b6d4ac7/FieldMate_Promo_Desktop.jpg?fm=webp&w=3840&q=85)