Prickly lettuce

A hardy weed that can cope with very dry conditions, prickly lettuce has become a significant weed in the last few years. Resistance to Group B chemistry (ALS inhibitor herbicides) was first detected in South Australia in the mid-nineties, so chemical control options are limited.

Description

Prickly lettuce plants can grow up to two metres high, with stiffy erect stems and bluish-green spiny leaves (margins and midribs). The early leaves that form the base and grow on the lower stem tend towards an oblong shape. Prickly lettuce flowers are pale yellow.

Control

Potato weed is spread via seed, producing several generations in one year that can remain dormant for some time. It is a very competitive plant that can form a dense mat, outcompeting newly germinating crop seedlings. It is best controlled by cultivation or herbicides.

Prickly lettuce should be included in an integrated weed management program that encompasses non-chemical practices as well herbicides. By using Velocity and Precept as part of your post-emergent herbicide rotation within that program, you can control prickly lettuce with developed resistance to older modes of action.