Multi-environment trial of early white food corn — ars.earlywhitecorn96 • agridat

Multi-environment trial of early white food corn for 60 white hybrids.

Format

A data frame with 540 observations on the following 9 variables.

loc: location, 9 levels
gen: gen, 60 levels
yield: yield, bu/ac
stand: stand, percent
rootlodge: root lodging, percent
stalklodge: stalk lodging, percent
earht: ear height, inches
flower: days to flower
moisture: moisture, percent

Details

Data are the average of 3 replications.

Yields were measured for each plot and converted to bushels / acre and adjusted to 15.5 percent moisture.

Stand is expressed as a percentage of the optimum plant stand.

Lodging is expressed as a percentage of the total plants for each hybrid.

Ear height was measured from soil level to the top ear leaf collar. Heights are expressed in inches.

Days to flowering is the number of days from planting to mid-tassel or mid-silk.

Moisture of the grain was measured at harvest.

Source

L. Darrah, R. Lundquist, D. West, C. Poneleit, B. Barry, B. Zehr, A. Bockholt, L. Maddux, K. Ziegler, and P. Martin. (1996). White Food Corn 1996 Performance Tests. Agricultural Research Service Special Report 502.

Examples

# \dontrun{
  
  library(agridat)
  
  data(ars.earlywhitecorn96)
  dat <- ars.earlywhitecorn96

  libs(lattice)
  # These views emphasize differences between locations
  dotplot(gen~yield, dat, group=loc, auto.key=list(columns=3),
          main="ars.earlywhitecorn96")
  ## dotplot(gen~stalklodge, dat, group=loc, auto.key=list(columns=3),
  ##         main="ars.earlywhitecorn96")
  splom(~dat[,3:9], group=dat$loc, auto.key=list(columns=3),
        main="ars.earlywhitecorn96")
  
  # MANOVA
  m1 <- manova(cbind(yield,earht,moisture) ~ gen + loc, dat)
  m1
#> Call:
#>    manova(cbind(yield, earht, moisture) ~ gen + loc, dat)
#> 
#> Terms:
#>                      gen      loc Residuals
#> yield            19200.2 378467.7   51875.0
#> earht             4782.2   4750.6    1652.1
#> moisture           446.1   6430.5     258.5
#> Deg. of Freedom       59        4       236
#> 
#> Residual standard errors: 14.82596 2.645798 1.046639
#> Estimated effects may be unbalanced
#> 240 observations deleted due to missingness
  summary(m1)
#>            Df Pillai approx F num Df den Df    Pr(>F)    
#> gen        59 1.6158    4.669    177    708 < 2.2e-16 ***
#> loc         4 2.1686  153.898     12    708 < 2.2e-16 ***
#> Residuals 236                                            
#> ---
#> Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
  
# }