7 Planting Dates (May 7, 16, 22, 29, June 11, 18 and July 2) 3 Plant Populations (25,000, 50,000 and 75,000 plants per hectare) 2 Soil Types (Chalmers, "darker" and Fincastle, "lighter")A split plot design with two replications was used. Spectral measurements, along with agronomic characterizations of the canopies and surface soil, were made at approximately weekly intervals throughout the growing season.
The spectral reflectance measurements were made with a Landsat band radiometer (Exotech Model 100). Radiant temperatures and overhead color photographs of the canopies were obtained simultaneously with the reflectance measurements.
The major agronomic measurements of the plots included growth stage, percent soil cover, height, leaf area index, biomass, and surface soil moisture and condition. Grain yields were measured at harvest time.
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Factor Level
Code Description Code Description
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1: Planting Date 0: Bare soil
1: May 7, 1980
2: May 16,1980
3: May 22,1980
4: May 29,1980
5: June 11,1980
6: June 18,1980
7: July 2,1980
2: Plant Population 0: Bare soil
1: 25,000 plants/ha
2: 50,000 plants/ha
3: 75,000 plants/ha
3: Soil 1: Chalmers silty clay loam -
"darker soil"
2: Fincastle silty loam -
"lighter soil"
4: Block or Replication 1: First block
2: Second block
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Experiment parameter 10: Radiant temperature as measured by a precision radiation thermometer (PRT-5) obliquely viewing the top surface of the canopy in Celsius degrees.