Submitted to: Journal of American Pomological Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 15, 2012
Publication Date: January 1, 2013
Citation: Tarara, J.M. 2013. Micrometeorological principles of protected cultivation. Journal of American Pomological Society. 67:2-6. Interpretive Summary: Fruit growers often use techniques to modify the environment, or microclimate, around their crops to achieve better quality or yields for their fruit. The principles of what is referred to as "microclimate modification" were detailed in this paper. These principles entail how practices like mulching the ground beneath the plants, or erecting greenhouses will change how heat moves in the crop. Because plant growth and development respond to temperature, influencing heat movement is critical to growing fruit where the climate is thought to be marginal for a particular crop. For example, cold spring temperatures can limit locations that produce cherries unless a "protected cultivation" intervention is used by the grower. Likewise, northern states may grow plants like spring flowers by using greenhouses or similar heated structures. Microclimate modification has been used by farmers for centuries, but it is only within the past few decades that technological advances have increased growers' options and the efficiency of those interventions.
Technical Abstract: Protected cultivation is a broad term commonly used among producers of specialty crops. Techniques can range from complex fixed structures to field site selection, to straightforward cultural practices in the field. This introduction to the ASHS workshop "Protected cultivation for fruit crops" considers techniques of protected cultivation in the broad sense. The text presents the physical principles associated with protected cultivation, namely heat transfer to and from the crop as expressed by the surface energy balance concept. Common terminology is introduced with respect to spatial and temporal scales. The four modes of heat transfer are discussed via the energy balance equation: radiation, convection, conduction, and latent heat fluxes. Illustrative examples of current practices in protected cultivation are provided in the context of the aforementioned physical principles.