Uniformity trial of oranges — parker.orange.uniformity • agridat

Uniformity trial of oranges at Riverside, CA, 1921-1927.

data("parker.orange.uniformity")

Format

A data frame with 1364 observations on the following 4 variables.

year: year
row: row
col: column
yield: yield, pounds/tree for plot

Details

An orchard of naval oranges was planted in 1917 at the University of California Citrus Experiment Station at Riverside. The orchard was maintained under uniform conditions for 10 years.

Eight Washington Navel orange trees in a single row constituted a plot. The planting distance is 20 feet between trees within the row and 24 feet between rows. Every other row was a guard row, so row 2 and row 4 were observational units, while row 3 was a guard row. For example, from row 2 to row 4 is 2*24 = 48 feet. Another way to think of this is that each plot was 48 feet wide, but only the middle 24 feet was harvested. At each end of the plot was one guard tree. Including guard trees at the row ends, each row plot was 10 trees * 20 feet = 200 feet long.

Field width (west-east) 10 plots * 200 feet = 2000 feet.

Field length (north-south) 27 plots * 48 feet = 1296 feet.

An investigation into the variability between plots included systematic soil surveys, soil moisture, soil nitrates, and inspection for differences in infestation of the citrus nematode. None of these factors was considered to be the primary cause of the variations in yield.

After the 7 years of uniformity trials, different treatments were applied to the plots.

Parker et al. state that soil heterogeneity is considerable and first-year yields are not predictive of future yields.

Table 25 has mean top volume per tree for each plot in 1926. Table 26 has mean area of trunk cross section.

Source

E. R. Parker & L. D. Batchelor. (1932). Variation in the Yields of Fruit Trees in Relation to the Planning of Future Experiments. Hilgardia, 7(2), 81-161. Tables 3-9. https://doi.org/10.3733/hilg.v07n02p081

References

Batchelor, L. D. (Leon Dexter), b. 1884; Parker, E. R. (Edwin Robert), 1896-1952; McBride, Robert, d. 1927. (1928) Studies preliminary to the establishment of a series of fertilizer trials in a bearing citrus grove. Vol B451. Berkeley, Cal. : Agricultural Experiment Station https://archive.org/details/studiesprelimina451batc

Examples

# \dontrun{

library(agridat)

data(parker.orange.uniformity)
dat <- parker.orange.uniformity

# Parker fig 2, field plan
libs(desplot)
dat$year <- factor(dat$year)
# 27 rows * 48 ft x 10 cols * 200 feet
desplot(dat, yield ~ col*row|year,
        flip = TRUE, aspect = 27*48/(10*200), # true aspect
        main = "parker.orange.uniformity")

# CV across plots in each year. Similar to Parker table 11
cv <- function(x) {
  x <- na.omit(x)
  sd(x)/mean(x)
}
round(100*tapply(dat$yield, dat$year, cv),2)
#>  1921  1922  1923  1924  1925  1926  1927 
#> 38.68 21.09 18.74 14.38 13.81 22.32 13.86 


# Correlation of plot yields across years. Similar to Parker table 15.
# Paker et al may have calculated correlation differently.
libs(reshape2)
libs(corrgram)
dat2 <- acast(dat, row+col ~ year, value.var = 'yield')
round(cor(dat2, use = "pair"),3)
#>        1921  1922  1923   1924  1925   1926   1927
#> 1921  1.000 0.660 0.168 -0.046 0.116 -0.290 -0.046
#> 1922  0.660 1.000 0.177  0.275 0.470  0.025  0.121
#> 1923  0.168 0.177 1.000  0.650 0.422  0.433  0.361
#> 1924 -0.046 0.275 0.650  1.000 0.759  0.681  0.605
#> 1925  0.116 0.470 0.422  0.759 1.000  0.651  0.558
#> 1926 -0.290 0.025 0.433  0.681 0.651  1.000  0.617
#> 1927 -0.046 0.121 0.361  0.605 0.558  0.617  1.000
corrgram(dat2, lower = panel.pts, upper = panel.conf,
         main="parker.orange.uniformity")


# Fertility index. Mean across years (ignoring 1921). Parker table 16
dat3 <- aggregate(yield ~ row+col, data = subset(dat, year !=1921 ),
                  FUN = mean, na.rm = TRUE)
round(acast(dat3, row ~ col, value.var = 'yield'),0)
#>      1   2   3   4   5   6   7   8   9  10
#> 1   87 103  96 103 113  NA  NA  NA 100 121
#> 2   95 106 119 104 120  NA  NA  NA 127 140
#> 3  111 110 109  99 140  NA  NA  NA 116 141
#> 4   78 112  98 114 128  NA  NA  NA 139 137
#> 5   98 113 116 110 122  NA  NA  NA 130 128
#> 6  102 109 122 128 113  NA  NA  NA 140 133
#> 7   93 126 137 128 108 132  NA  NA 132 138
#> 8  100 116 129 119 113 130  NA  NA 100 107
#> 9   92 115 112 119 120 132  NA  NA 124 105
#> 10  98 116 127 135 124 131  NA  NA 116 104
#> 11  98 138 132 137 138 116 120  NA 122 124
#> 12 103  NA 121 119 115 114 123  NA 118 121
#> 13  97 121 104 110 117 115 103  NA  NA 130
#> 14 119 119 129 132 129 138 140  NA  NA 116
#> 15 108 131 148 130 152 153 140  NA  NA 136
#> 16 127 127 135 134 126 129 133 152  NA 139
#> 17 119  NA 140 134 121 139 134 128  NA 128
#> 18 135 146 146 147 150 143 127 138  NA 136
#> 19 120 137 119 124 136 142 148 128  NA 133
#> 20 121 138 135 139 142 150 132 130  NA 122
#> 21 114 128 157 146 144 142 155 153  NA 138
#> 22 107 126 143 134 126  NA 144 165  NA 144
#> 23  NA  NA  NA  NA  NA 126 155 155  NA 146
#> 24  NA  NA  NA  NA  NA 129 150 140  NA 118
#> 25  NA  NA  NA  NA  NA 134 142 131  NA 115
#> 26  NA  NA  NA  NA  NA 114 150 149  NA 122
#> 27  NA  NA  NA  NA  NA 114 136  NA  NA 108

libs(desplot)
desplot(dat3, yield ~ col*row,
        flip = TRUE, aspect = 27*48/(10*200), # true aspect
        main = "parker.orange.uniformity - mean across years")

# }