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An observational study was conducted to explore the relationship between seed production and plant characteristics in rye-grass. Between 17 and 24 samples were collected at each of four study sites (Site: C, L, P, and W). For each sample point, the total number of seeds per square meter (TotalSeed), the average head length in millimeters (HLength), and the average number of spikelets per head (Spikelets) were measured. This dataset facilitates analysis of how head length and spikelet count may influence seed yield across multiple field sites.

Usage

weedseed

Format

A data frame with 5 variables: Sample, Site, HLength, Spikelets, TotalSeed.

Sample

Factor. Unique identifier for each sample point.

Site

Factor. Study site where the sample was collected (levels: "C", "L", "P", "W").

HLength

Numeric. Average head length of rye-grass plants at the sampling point (in millimeters, mm).

Spikelets

Numeric. Average number of spikelets per head at the sampling point.

TotalSeed

Integer. Total number of seeds per square meter at the sampling point.

Source

Welham, S. J., Gezan, S. A., Clark, S. J., and Mead, A. (2015) Statistical Methods in Biology: Design and analysis of experiments and regression

Examples

anova(lm(log10(TotalSeed) ~ Site * (HLength + Spikelets) , data = weedseed))
#> Analysis of Variance Table
#> 
#> Response: log10(TotalSeed)
#>                Df  Sum Sq Mean Sq  F value  Pr(>F)    
#> Site            3 13.2175  4.4058 108.2169 < 2e-16 ***
#> HLength         1  0.2905  0.2905   7.1363 0.00926 ** 
#> Spikelets       1  0.1554  0.1554   3.8170 0.05446 .  
#> Site:HLength    3  0.2092  0.0697   1.7127 0.17162    
#> Site:Spikelets  3  0.0797  0.0266   0.6524 0.58392    
#> Residuals      75  3.0535  0.0407                     
#> ---
#> Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1