Puncturevine control can be a long process


Diligence needed to get rid of potentially harmful weed that thrives in dry soils.


By Susan McIver P


uncturevine is distinguished by its spiny seedpods that can damage the feet of humans, wildlife and domestic animals. If ingested by animals, injury to the mouth, stomach or intestinal linings can occur — and the pods also can puncture the tires on bicycles and other small vehicles. Lisa Scott and Ken Sapsford teamed up at this year’s viticulture and enology conference to talk about puncturevine and preliminary results from control trials.


Never leaving


land bare is another important component of control.


“Do competitive


planting,” Scott said.


She and Sapsford used a grass mix consisting of 85 per cent Creeping Fescue, five per cent Canada Bluegrass and Kentucky


Bluegrass, three per cent Single Cut Red Clover and two per cent Yarrow in test plots.


SUSAN MCIVER


Lisa Scott and Ken Sapsford hold samples of puncturevine.


attached to tires and the bottom of boots.


Scott is the program manager for the Okanagan and Similkameen Invasive Species Society and Sapsford is a pesticide consultant for the B.C. Ministry of Agriculture. Originally introduced from the Mediterranean, puncturevine was first recorded in California in 1903.


Also known as bullhead or goathead, puncturevine made its way north, with its first sighting in Canada in Osoyoos during the early 1970s.


“In B.C., it occurs only in the Okanagan Valley as far north as Vernon, and in the lower Similkameen region,” Scott said. The plant itself is an annual, forming dense mats on dry, sandy or gravely soils such as occur on roadsides, parking lots and beaches.


“Puncturevine can be found in gravel pits from the South Okanagan all the way to Vernon,” Scott said. Agricultural areas commonly infested include vineyards, pastures and lands used for growing ground crops. “Puncturevine requires less water than most plants,” Scott


said.


Several approaches are needed to eliminate this noxious weed from infested areas and to prevent its further spread. “Small infestations can effectively be controlled by hand- pulling or digging before flowering and seed production,” she said.


New plants usually appear in late May, but this year some were spotted as early as April, Scott reported. “It’s necessary to check your property every three weeks until frost, because new plants continue to germinate throughout the summer,” Scott said.


Vigilance is required for several years to ensure that the seed bank in the soil is depleted.


Large infestations can be tilled before seed production, but farmers must be quick because seeds can be formed within a month after the plant begins to grow.


British Columbia FRUIT GROWER • Fall 2016 11


Jeff Martin of LaFrenz Winery spoke of his frustration with water meter readers who bring seedpods into his Oliver


Puncturevine can be spread in a variety of ways, including the


seedpods becoming


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