Michael E. Wisniewski and Charles L. Wilson
Charles L. Wilson, Michael E. Wisniewski and Bruce L. Upchurch
An apparatus was designed and built to deliver micronized dust particles to the foliage of mature orchard trees under a mobile canopy. The dust is propelled by compressed air (about 1120 kPa), which is pulsed through sand-blast guns using the Bernoulli effect. The canopy consists of steel pipes that support the cover and serve as a conduit for compressed air that flows to the guns. Quick-coupling fittings on the canopy pipes allow for easy attachment and removal of multiple guns at various, optional positions. The support structure for the canopy is attached to a mobile trailer, which transports it over mature orchard trees while the dust is being applied. The canopy reduces drift and enhances the coverage of dusts while they are being applied. This innovative apparatus can be used to apply pesticides, growth promoters and regulators, fertilizers, and biocontrol agents in powdered form. The distribution of corn starch on apple foliage is assessed using this invention.
Charles L. Wilson, Jose M. Solar, Ahmed El Ghaouth and Deborah R. Fravel
An apparatus was developed for the rapid and facile evaluation of soil fumigants in a controlled manner using small volumes of soil. The apparatus consisted of a manifold to which were attached six canisters containing a loamy sand soil (adjusted to –100 kPa soil water potential). The soil was infested with either conidia of Fusarium oxysporum or Trichoderma harzianum; sclerotia of Sclerotinia minor; ascospores of Talaromyces flavus; vermiculite colonized with Pythium aphanidermatum; or beet (Beta vulgaris L., cv. Detroit Red) seed colonized with Rhizoctonia solani. Using nitrogen gas (N2) as a carrier gas, either N2 or N2 plus benzaldehyde was passed continuously through the soil for 24, 48, or 72 hours. At all three exposure times, benzaldehyde + N2 reduced viability of R. solani and S. minor, and reduced populations of P. aphanidermatum and T. harzianum. Populations of F. oxysporum were reduced after 48 and 72 hours of exposure to benzaldehyde, whereas populations of T. flavus were reduced only after 72 hours of exposure. Fumigation with benzaldehyde + N2 for 24 hours did not affect soil pH 1 week after exposure, but fumigation for 48 or 72 hours temporarily lowered pH from an average of 6.86 to 5.57 and 5.32, respectively. The biocontrol fungus, T. flavus, was less sensitive to benzaldehyde than the pathogens or the biocontrol fungus, T. harzianum. Thus, combining T. flavus with benzaldehyde to enhance biocontrol may be possible.