In trial 1, S. riobrave were applied at 0, 11, 22, and
54 IJs/cm2 and H. bacteriophora and H. indica at 11
and 22 IJs/cm2 on June 2 and 4, 1998. Sponge-formulated
heterorhabditid nematodes were released into a
pail containing 15 liters of water prior to tank mixing.
The suspension of nematodes was then added to the
spray tank in 378.5 liters of well water with a pH of ;7
during sprayer pump agitation. Nematodes were applied
using a tractor-mounted herbicide applicator
with twin 1.5-m booms in approximately 153 liters of
water/ha at a ground speed of 2.4 kmph. Each boom
configuration had four fan nozzles (No. 10) located 30
cm apart to allow for coverage of the soil from the edge
of the tree canopy to the trunk and one flood jet nozzle
(No. 8-OC) mounted on the tip of each boom to cover
the area (0.8-m strip) extending from the tree trunk
toward the outer (opposite to applicator) margin of the
tree. The filters were removed from all spray nozzles
during application. The liquid formulation of S. riobrave
was poured directly into the sprayer holding