• The Journal of Natural Sciences
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• v.11 no.1
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• pp.137-142
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• 1999

JC Raulston Arboretum of the North Carolina State University houses 113 species of Korean native landscape woody plants. Styrax japonicus 'Emerald Pagoda'[formerly 'Sohuksan'] is native to Korea, China, and Japan. 'Emerald pagoda' is a special cultivar found by DR. J.C. Raulston during the United States National Arboretum plant collection expedition of the island of Sohuksan at the Western end of the Korea in 1985. Incredible, thick, glossy, large-leafed form of this beautiful white flowering tree found in Korea in 1985. It was probably the most outstanding ornamental plant to come from the expedition after his trip to Sohuksan and Chindo in the harsh perilous islands of the coast of Korea. He brought this one back in his suitcase. Viburnum awabuki 'Chindo' is and evergreen broadleaf shrub. It is for screening and as fire resistant trees in the southern region of Korea, because of its compact, leathery leaves. 'Chindo' was discovered on the island of Chindo by the U.S. National arboretum plant exploration team including J.C. Raulston during its 1985 Korean trip. Cuttings were taken from this plant, and liners were produced over subsequent years. These liners are now being evaluated for hardiness and fruit production throughout the Southeast of USA.

• Journal of Biosystems Engineering
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• v.36 no.1
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• pp.15-22
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• 2011

An experimental variable rate nursery sprayer was developed to adjust application rates for canopy volume in real time. The sprayer consisted of two vertical booms integrated with ultrasonic sensors, and variable rate nozzles coupled with pulse width modulation (PMW) based solenoid valves. A custom-designed microcontroller instructed the sensors to detect canopy size and occurrence and then controlled nozzles to achieve variable application rates. A spray delivery system, which consisted of diaphragm pump, pressure regulator and 4-cycle gasoline engine, offered the spray discharge function. Spray delay time, time adjustment in spray trigger for the leading distance of the sensor, was measured with a high-speed camera, and it was from 50 to 140 ms earlier than the desired time (398 ms) at 3.2 km/h under indoor conditions. Consequently, the sprayer triggered 4.5 to 12.5 cm prior to detected targets. Duty cycles of the sprayer were from 20 to 34 ms for senor-to-canopy (STC) distance from 0.30 to 0.76 m. Outdoor test confirmed that the nozzles were triggered from 290 to 380 ms after detecting tree canopy at 3.2 km/h. The spray rate of the new sprayer was 58.4 to 85.2% of the constant application rate (935 L/ha). Spray coverage was collected at four areas of evergreen canopy by water sensitive papers (WSP), and ranged from 1.9 to 41.1% and 1.8 to 34.7% for variable and constant rate applications, respectively. One WSP area had significant (P < 0.05) difference in mean spray coverage between two application conditions.