In conventional greenhouse systems, recent innovations have contributed to increased production levels, and at the same time, to the decreased ecological footprint in terms of the reduction of water use, nutrients and CO2 emissions. Several examples of application of standard and innovative technologies to improve production, optimize utilization of solar energy and increase efficiency of energ...

objective: sweet potato whitefly, bemisia tabaci gen. (b. tabaci), is one of the most important pests of various greenhouse crops in iran. nowadays, chemical insecticides are broadly used for control of the pests that causes risk to consumer's health. for the first time, contact toxicity of pelargonium roseum andrews and artemisia sieberi besser essential oils on b. tabaci and its possible...

the greenhouse whitefly, trialeurodes vaporariorum westwood (hem.: aleyrodidae) is a polyphagous and key pest that causes damaging to wide range of crops. the parasitoid wasp, eretmocerus delhiensis mani (hym.: aphelinidae) is a syn-ovigenic and thelytokous species that parasitizing greenhouse whitefly nymphs. in order to evaluation parasitoid wasp, eretmocerus delhiensis mani (hym.: aphelinida...

Differences in soil nitrous oxide (N2 O) fluxes among ecosystems are often difficult to evaluate and predict due to high spatial and temporal variabilities and few direct experimental comparisons. For 20 years, we measured N2 O fluxes in 11 ecosystems in southwest Michigan USA: four annual grain crops (corn-soybean-wheat rotations) managed with conventional, no-till, reduced input, or biologica...

Perennial bioenergy crops have significant potential to reduce greenhouse gas (GHG) emissions and contribute to climate change mitigation by substituting for fossil fuels; yet delivering significant GHG savings will require substantial land-use change, globally. Over the last decade, research has delivered improved understanding of the environmental benefits and risks of this transition to pere...

In this work we present an application developed in Derive 6 to compose counterpoints for a given melody (“cantus firmus”). The result is non deterministic, so different counterpoints can be generated for a fixed melody, all of them obeying classical rules of counterpoint. It is also possible that the counterpoint could not be generated, in this case, backtracking techniques have been implement...

Musical scores are some of the most important learning tools for musicians’ acquisition of musical knowledge. However, despite their educational relevance, very little is known about how music students conceive of these cultural external representations. Given that these conceptions might act as mediators of students’ learning approaches, the importance of knowing these conceptions seems eviden...

to study the root allelopathic effects of cool season crops on germination and early growth of three crops (sorghum, corn, and soybean), an experiment was conducted in seed research laboratory and greenhouse of college of agriculture, university of tehran. the experiment consisted of four cool season crops (wheat, barley, rye and pea) and control as the main plots, three spring-crops (corn, soy...