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treatment. On the other end of the spectrum, ethylene production and respiration are expected to be directly linked to 1-MCP application and they were generally reported to be affected. However, because ethylene production and respiration are not quality

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have similar attributes. GIS systems involve visualizing and comparing many of these layers together in the form of a map. For example, a GIS system may have one layer containing spatial soil data and another layer containing GDD spatial data. Layers

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deposition and pesticides were considered to be negligible because of the close system in the greenhouse and the low-rate application of pesticides ( Table 3 ). Nitrogen outputs in aboveground plant parts were calculated from the N concentration in each

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Apple orchards are highly diversified and complex ecological and economic systems. Production is affected by a wide range of insects, diseases, weeds, and mammalian pests. The incidence of these pests is often dependant upon climatological effects; and the microclimate within orchards. An expert system, a form of artificial intelligence, has been developed and commercially released to apple growers that utilizes weather data to make recommendations regarding production decisions. Users of the system are instructed on how to establish a weather station, and to collect, and input weather data from the farm. The information is utilized to calculate disease infection periods and pesticide residues to arrive at a control recommendation. Other weather dependant modules include the scheduling of trickle irrigation as well as water application rates during a frost. An interactive demonstration of the system will be presented to the group.

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application of 10 tons/acre can return from $7850/acre for tomatoes to $17,760/acre for zucchini ( Table 5 ). Vegetable-cropping systems without the addition of external green waste or livestock manure are possible and profitable ( Schmutz et al., 2007

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New technologies such as differential global positioning systems (DGPS) and geographical information systems (GIS) are making it possible to manage variability in soil properties and the microenvironment within a field. By providing information about where variability occurs and the patterns that exist in crop and soil properties, DGPS and GIS technologies have the potential of improving crop management practices. Yield monitoring systems linked to DGPS receivers are available for several types of horticultural crops and can be used in variety selection and/or improving crop management. Precision soil sampling and remote sensing technologies can be used to scout for infestations of insects, diseases, or weeds, to determine the distribution of soil nutrients, and to monitor produce quality by measuring crop vigor. Combined with variable rate application systems, precision soil sampling and remote sensing can help direct fertilizer, herbicide, pesticide, and/or fungicide applications to only those regions of the field that require soil amendments or are above threshold levels. This could result in less chemical use and improved crop performance. As with any information driven system, the data must be accurate, inexpensive to collect, and, most importantly, must become part of a decision process that results in improvements in crop yield, productivity, and/or environmental stewardship.

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flower abscission in floricultural commodities, and, in some instances, fruit decay have been reduced by postharvest 1-MCP application. 1-MCP is odorless, colorless, effective at low concentrations, and persistent in its effects in many crops

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Ebb-and-flow systems can be used to apply systemic pesticides to greenhouse crops without worker exposure or runoff. However, there is little information on the efficacy of pesticides applied with ebb-and-flow systems. We are using silverleaf whitefly (Bemisia argentifolii) control on poinsettia (Euphorbia pulcherrima) with imidacloprid as a model system to study pesticide efficacy in ebb-and-flow systems. The objective of this study was to determine the effect of the amount of insecticide taken up by the pot on the efficacy of whitefly control. Different amounts of imidacloprid uptake were obtained by not watering the plants for 0, 1, 2, or 4 days before the imidacloprid application. The imidacloprid (132 g·L–1) was applied once when the roots of the cuttings had reached the side of the pots. These treatments were compared to an untreated control on ebb-and-flow and a standard drench application (100 mL) to hand-watered plants. Pots in the different subirrigation treatments absorbed 12 to 175 mL of imidacloprid solution. Four days after the application, leaf tissue of the hand-watered plants contained 8 to 20 times more imidacloprid than the subirrigated plants. Efficacy was determined from the percentage of surviving mature whiteflies after 2 days on the plants and by counting the number of immatures after 2 weeks. Surprisingly, imidacloprid efficacy was better in the subirrigated imidacloprid treatments than in the hand-watered treatment. Whitefly control in all subirrigated imidacloprid treatments was excellent, irrespective of the amount of imidacloprid solution taken up by the pots.

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Abstract

A 4-channel, microcomputer-based counting system for one method of seed vigor analysis is described. The system consists of a display/interface module and a hand-held probe/switch assembly. The instrument contains 4 count displays and has 2 serial output interfaces to allow recording of the count data. The operator manipulates seeds with the hand-held probe and enters the visually selected seed vigor rating by pressing the appropriate switch on the probe handle. Audible feedback of different pitch for each channel is provided to confirm that the correct switch was depressed. The instrument greatly reduces the amount of labor required to obtain and analyze these data as compared to completely manual methods. Although designed for seed vigor analysis, the instrument could also be used in other applications where counting of items in a mixed sample is necessary.

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system OP did not practically reduce the uniformity of water application, although certain drip tape type may show greater variations in emitter flow. Table 2. Emitter flow variation ( q var ), coefficient of variation ( cv ), and uniformity coefficient

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