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performance, and rates necessary for maximum efficacy made the treatment costly. Additionally, sprayer configuration was reported to be an important consideration to ensure maximum efficacy, with high sprayer output volume necessary to ensure adequate spray

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Abstract

The radiant fractions of four currently available orchard heaters (spot, large cone, return stack and auto clean stack) were determined under orchard conditions using observed surface temperatures, emissivity and the Stefan-Boltzmann Law. The contribution of the flame extending above the spot heater stack to its total radiant output was determined. Stack surface temperatures increased with burning rate on the large cone, return stack and auto clean stack heaters but decreased on the spot heater. The position of the highest temperature was near the bottom of the large cone, return stack and auto clean stack heaters and near the top of the spot heater. Surface temperatures were lower in general on the spot heater than on the other three heaters. The radiant fractions of the large cone, return stack and auto clean stack heaters were greater than 20% and relatively constant with burning rate. Even though the flame contribution is purposely overestimated the radiant fraction of the spot heater was less than 16%. For low wind speeds under which most orchard heating occurs the effect of wind speed on the radiant fraction was negligible.

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-level sales or cash receipts, this summary only presents those studies that attempted to evaluate the postfarm gate economic impacts, including total employment and payroll associated with green industry sectors. Total output impacts estimated in these

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study for 2002, Florida's green industry had total employment impacts of 147,795 jobs, output impacts of $10.0 billion (B), and value-added impacts of $7.1 B ( Hall et al., 2006 ). These results represented significant increases in Florida since previous

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Abstract

The objective of this study was to examine the effects of pollen competition on offspring quality in the common zucchini squash (Cucurbita pepo L.). In a controlled field study, we compared the performance of seeds that were produced under conditions of pollen competition (high pollen loads) to seeds produced under conditions of little or no pollen competition (low pollen loads). We found that seeds from high pollen loads were more likely to emerge and emerge more rapidly than seeds from low pollen loads. The high pollen load seedlings also tended to produce more flowers and fruits than the low pollen load seedlings. On a per-plant basis, the high pollen load progeny had significantly greater fruit volume, seed numbers, and total seed weight than the low pollen load progeny. We conclude that in zucchini, seeds produced under conditions of pollen competition are “superior” to seeds produced when pollen competition is minimal or absent. The significance of these results is considered in light of a previous study revealing nonrandom patterns of fruit abortion in this species.

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turfgrass industry of each state in terms of output values, value added, and employment. We first survey homeowners to estimate their preferences for the proposed new varieties and then we calculate the potential shares of the turfgrass market that the

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, which facilitates generating a specific (sometimes adjustable) spectral output, 2) LEDs produce less radiant heat per photon, 3) LEDs can have a longer operating life, 4) individual LEDs are low power and small in size, allowing for small, low

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evaluated for space flight applications in the 1990s. LED technology has developed rapidly over the past decade with increasing flux output becoming available at decreasing prices. As the price of LEDs has decreased, there has been a renewed interest in the

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Solid-state lighting using light-emitting diodes (LEDs) represents a fundamentally different technology from the gaseous discharge-type lamps currently used in horticulture. Capabilities like spectral composition control and high light output with

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economic contributions of the industry in 2002 given as 1.96 million full-time and part-time jobs, $147.8 B in industry output, and $95.1 B in value added or GDP, expressed in 2004 dollars. In a follow-up study for 2007–08, the total national contributions

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