Submitted to: Washington State Weed Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: September 1, 1994
Publication Date: N/A
Interpretive Summary: Puncturevine is a serious weed problem in many irrigated horticultural crops in the Pacific Northwest. The high level of dormancy in the seed allows puncturevine to escape many control practices. Several strategies for successful control of puncturevine include: 1) Continuous field scouting season long; 2) Proper timing and selection of herbicides that prevent new seed production; 3) Introduction of biological control agents; 4) Deep burial of the seed; and 5) Establishment of a competitive crop.
Technical Abstract: Puncturevine is a serious weed problem in irrigated crops grown in the Pacific Northwest. Puncturevine emerges from early April through September and has a high level of dormancy. Puncturevine seedlings continued to emerge for four consecutive years following on initial planting. Puncturevine was unable to emerge from depths much greater than 5 cm. Seed production was greatest from plants emerging in May, June, and July, and least in plants emerging in mid August. Numerous herbicides are active on puncturevine but often fail to control the weed due to late season emergence of seedlings. Two weevils have successfully reduced puncturevine populations in southern United States, but have not overwintered in Washington State.