Fungus gnats (Bradysia spp.) are major insect pests in greenhouses. The adult stage is primarily a nuisance whereas the larval stage is directly responsible for plant injury by feeding on plant roots or tunneling into stems. Insecticides are used to deal with fungus gnat larvae in growing medium, although sometimes with limited success. This study evaluated the potential of using a soil amendment—diatomaceous earth (DE) incorporated into growing media—for controlling the fungus gnat Bradysia sp. nr. coprophila. Two experiments were conducted by testing a series of growing media containing various concentrations of diatomaceous earth, and several without diatomaceous earth. The effects of the growing media containing diatomaceous earth on both the 2nd and 3rd instars of fungus gnat larvae were determined by recording the number of adults captured on yellow sticky cards (2.5 × 2.5 cm). Based on the results obtained from both experiments, the addition of DE to growing medium, at the concentrations tested, did not negatively affect or increase efficacy against both the 2nd and 3rd instars. This suggests that incorporating DE into commercially available growing medium may not be beneficial to greenhouse producers. However, further research is needed to assess whether differential larval susceptibility and moisture content influence the ability of DE to control soil-dwelling arthropods.
Raymond A. Cloyd and Amy Dickinson
Most growing media have a more or less pronounced hydrophobic character in relation to their moisture level ( Michel et al., 2001 ). To remedy this, the addition of mineral materials or wetting agents has been proposed. However, the influence of
John J. Sloan, Raul I. Cabrera, Peter A.Y. Ampim, Steve A. George, and Wayne A. Mackay
diffuse out of those pores when the expanded shale aggregate is again surrounded by water ( Sloan et al., 2000 ). This property could make expanded shale a beneficial ingredient of growing media, especially when combined with decomposable organic materials
Yinping Li, Raymond A. Cloyd, and Nora M. Bello
media, 2) the effect of pyriproxyfen in two growing media on western flower thrips pupae, and 3) the residual activity of pyriproxyfen in growing medium on western flower thrips pupae 3, 5, 7, and 14 d after treatments were applied. Materials and Methods
Hanna Y. Hanna
increase plant yield to gain a fair market share among major producers. Previous research has indicated that perlite growing media can be recycled to save money ( Hanna, 2005 , 2006 ), and precision heating can reduce production costs ( Hanna and Henderson
Nadia Jiménez-Peña, Luis A. Valdez-Aguilar, Ana M. Castillo-González, María T. Colinas-León, Andrew D. Cartmill, and Donita L. Cartmill
nutrients in the media solution and the physical and chemical properties of the growing media may affect the response of plants to a specific substrate and nutrient solution formulation. Tree bark is a traditionally used media for orchid cultivation in
Samuel E. Wortman, Michael S. Douglass, and Jeffrey D. Kindhart
, both of these challenges can be at least partially addressed by growing strawberries in a hydroponic system within high tunnels. Hydroponic production, through the use of nutrient solution or soilless substrates as growing media, eliminates weed
Nathan J. Herrick and Raymond A. Cloyd
). However, there are unsubstantiated allegations made by a manufacturer that certain plant-growing media containing B. pumilus and an arbuscular mycorrhizal fungus, Glomus intraradices , negatively affect the survival of western flower thrips pupae and
Horticultural schools are always looking for fresh material for their classes. The Canadian Sphagnum Peat Moss Association (CSPMA) has developed a lesson plan entitled Growing Media and Soil Amendment that is ideal for horticultural or greenhouse management courses. The teaching plan includes terms and definitions on all types of peatmoss and commonly used terms related to the resource. It discusses characteristics and qualities of world peat resources as well as comparisons of physical, chemical, and biological properties of organic materials used in growth media and as soil amendments. In addition to the research information on peat and other soil amendments, the teaching plan addresses the environmental issues surrounding the use of wetlands, including peatlands and the effects of peat harvesting on the environment. The plan introduces students and instructors to the reclamation and restoration efforts that have been developed and used to preserve the harvested bogs in Canada. The curriculum is divided into two sections: one for the students, which includes handouts and one for the instructor, with more in-depth background information.
Michael Compton and Timothy Zauche
Soilless horticultural growing media are composed of organic matter, coarse aggregates, nutrients, and a wetting agent. Sphagnum peat has been the standard organic addendum to soilles growing media. However, recent shortages, escalating costs, and its acidity make sphagnum peat a sometimes less-than-desirable material. Alternatives such as composted bark dust, coconut coir, composted manure, and crop by-products have been proposed as substitutes for sphagnum peat, but none are a suitable general alternative. Anaerobic digestion-derived biosolids (ADB) has the potential to become a complete or partial substitute for sphagnum peat. ADB is a cellulosic product similar in appearance to sphagnum peat and is a product from the anaerobic digestion of cattle manure for 14 to 25 days at temperatures between 104 °F. and 140 °F. Bacteria from the animal's rumen, present in the manure prior to anaerobic digestion, are used to breakdown excessive nutrients present in the manure. Following anaerobic digestion, the nutrient-rich liquid phase is removed to yield an odorless cellulosic fiber that is sterile, free of weeds, pests, and pathogens, as well as uniform and reproducible. The potential application of ADB to the horticulture industry, most specifically as an organic addendum to soilless media, is immense and will be discussed. Use of anaerobic digester-derived biosolids in horticultural growing media is a protected intellectual property and available for license through the WiSys Technology Foundation.