نتایج جستجو برای: greenhouses
تعداد نتایج: 2040 فیلتر نتایج به سال:
To enhance biological control of insect pests in greenhouses, facilities and procedures for mass production of the parasitoids, Eretmocerus sp., Encarsia formosa, and Trichogramma brassicae, and the predator, Aphidoletes aphidimyza were successfully developed in Hengshui, Hebei province, China. Mass production of the aphelinid wasps was achieved by using different plant varieties and host insec...
Soils at depths of 0 cm to 10 cm, 10 cm to 20 cm, and 20 cm to 40 cm from 37 vegetable greenhouses in Shandong Peninsula, East China, were collected, and 16 phthalic acid esters (PAEs) were detected using gas chromatography-mass spectrometry (GC-MS). All 16 PAEs could be detected in soils from vegetable greenhouses. The total of 16 PAEs (Σ16PAEs) ranged from 1.939 mg/kg to 35.442 mg/kg, with an...
The pollination effectiveness of the stingless bee Melipona quadrifasciata and the honey bee Apis mellifera was tested in tomato plots. The experiment was conducted in four greenhouses as well as in an external open plot in Ribeirão Preto, SP, Brazil. The tomato plants were exposed to visits by M. quadrifasciata in one greenhouse and to A. mellifera in another; two greenhouses were maintained w...
This paper applied a non-parametric (Data Envelopment Analysis) method to analyze the efficiency of farmers, discriminate efficient farmers from inefficient ones and to identify wasteful uses of energy in order to optimize the energy inputs for greenhouse cucumber production in Lorestan province of Iran. Data were collected from 27 cucumber producers by using a face-to-face questionnaire.DEA cr...
With the rapid development of greenhouses, indoor air quality, particularly airborne microorganisms, is closely related to health farmers and needs more attention. In this study, concentrations fungi at seedling, fruiting harvesting stages in typical tomatoes greenhouses were tested. Temperature, relative humidity microbial analysed. It was found that dominant fungal genera are Aspergillus Clad...
Two natural enemy species are frequently released simultaneously to control one pest species in augmentative biological control in greenhouses. Intraguild predation (IGP) and interspecific competition between natural enemies might affect the biological control. IGP occurs between two parasitoids, between one parasitoid and one predator, and between two predators. Although unidirectional IGP has...
In this paper, it is proposed an irrigation control system able to use in an efficient way the water in greenhouses of heterogeneous plants without sacrificing the good condition of them, to accomplish this, firstly it is proposed a clustering of plants based on the irrigation needs and secondly implementation of a genetic algorithm that establishes the optimum watering times and waiting betwee...
Introduction Growing tomatoes in greenhouses allows producers to grow plants at a time when it would be impossible to grow outside because of the weather. The sole purpose of a greenhouse is to maintain an environment that promotes optimum production. Solar energy from the sun provides both sunlight and heat, but growers must provide a system that maintains the optimum growing environment in th...
ODC 164.5: 161(485j[-174.7 Pinus sylvestris + 174.7 Picea abies] The influence of growing conditions upon the pignzentation in needles from xeedlings o f Scots pine and Norway spruce has been studied. The plant material was grown either in the open or in plastic greenhouses. The greenhouses were covered with plastic during the vegetation periods from May to August, and during the rest of the ye...
The present work has developed a methodology based on thermography and sonic anemometry for studying the microclimate in Mediterranean greenhouses equipped with air heaters and polyethylene distribution ducts to distribute the warm air. Sonic anemometry allows us to identify the airflow pattern generated by the heaters and to analyze the temperature distribution inside the greenhouse, while the...
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