Mechanical management of weeds - Ecological Management of Agricultural Weeds - page 185

Figure 4.18 Rubber-finger weeder.
from properly set tools will be no more than a few percent, and is often negli-
gible. Cultivation late on a sunny day when crop stems are less turgid reduces
mortality. Several studies have examined spinners in conjunction with other
in-row and near-row tools (Schweizer, Westra & Lybecker, 1994; VanGessel et
al ., 1995 b ; Mohler, Frisch & Mt. Pleasant, 1997), but so far, controlled investi-
gations of these tools have been minimal.
Rubber-finger weeders consist of two pairs of ground-driven wheels
equipped with rubber fingers that stir the surface soil in the row, but bend
around well-rooted crop plants. These are followed by wire baskets that
aggressively stir the area adjacent to the row (Figure 4.18).The rubber fingers
are stiff, so weeding in the row requires that crop stems be tough and well
rooted.The implement is commonly used to weed nursery stock.
Rotary hoes, weeding harrows, and some in-row tools commonly reduce
crop density by several percent (Rasmussen, 1991, 1992 a ; Buhler, Gunsolus &
Ralston, 1992; Mulder & Doll, 1993; Rydberg, 1994; Mohler, Frisch & Mt.