Comprehensive information on Nitrogen Use Efficiency for cereal crop production, N use Efficiency

 

Research Methods in Agriculture

Stability Analysis

Stability Analysis (treatment by environment interactions)

Stability Analysis (Plant Breeding, Dr. Klatt, Sarah) 

Contribution of Breeding to Yield Advances in Maize (Don Duvick)

Magruder excel file
Use of Stability Analysis for Long-Term Soil Fertility Experiments (pdf, Agron J. 85:159-167)
Stability Analysis (excel) (Step by Step)

1. Sarah Stability Analysis (Genotype by Environment interactions, plant Breeding)

2. Stability Analysis (excel) (Treatment by environment interactions, N Rate Example)

(example for agronomic experiments, Use of Stability Analysis for Long-Term Soil Fertility Experiments.  Agron J. 85:159-167)

3. Magruder excel file

Transpose Function, OUTPUT DATA (2 examples)

data one;
input yr trt yield;
cards;
88        1          1000
88        2          2000
88        3          2400
89        1          4000
89        2          3200
89        3          3500
92        1          6000
92        2          7200
92        3          8800
data two; set one;
proc sort; by trt yr;
proc transpose data = two out = three prefix = y ;
id yr;
var yield;
by trt;
proc print;
run;

data one;
input YR TRT BUAC;
cards;
1893	1	10.5
1893	2	10.5
1894	1	20.9
1894	2	20.9
data two; set one;
if trt <3 then delete;
if trt >4 then delete;
data three; set two;
proc sort; by yr trt;
proc means noprint; by yr trt; var buac;
output out = new mean = ybuac;
data new1; set new; proc sort; by yr;
proc transpose data = new1 out = three prefix = trt;
by yr;
id trt;
var ybuac;
proc print;
run;

 

Procedure for Determining Differences in Population Means
data one; input sample time $ ph P oc k;
cards;
1          A         6.17    21.47  0.924  150
2          A         6.27    18.69  0.939  139
3          B         6.16    21.20  1.042  142
4          B         5.65    41.74  1.054  144
proc ttest;
class time;
var ph oc;
run;

A.  Proc Corr (r values)   (see added proc procedures that go with this data set)

data one;
input ndvi buac gn ph sn sp;
cards;

0.6205 34.42627 2.5107 6.39 0.10469 32.80725
0.294 18.51818 2.59762 5.54 0.0788 2.52685
0.429 24.41195 2.2206 5.40 0.0756 42.48705
0.4335 35.67636 2.6788 5.00 0.09356 28.1535
0.413 37.01768 2.8313 4.79 0.08893 44.907
0.5675 39.72107 2.8135 4.99 0.09549 35.04105
0.62347 19.14847 2.2536 6.48 0.08441 35.6701
0.290535 6.427076 2.1697 5.43 0.0715 6.8042
0.31301 8.449443 1.9589 5.44 0.06613 46.92191
0.684435 23.14757 2.5939 4.86 0.08623 50.63324
0.713725 23.81803 2.5314 4.75 0.07685 56.93661
0.7247 24.93252 2.8309 5.14 0.07576 46.68627
0.736 39.52 1.9444 6.55 0.08145 43.52569
0.286 15.22 1.7883 5.40 0.052864 7.91341
0.389 19.41 1.5578 5.32 0.05636 68.54739
0.661 44.37 1.7588 4.72 0.08549 56.56025
0.666 46.67 1.7828 4.64 0.06896 51.67229
0.740 44.76 1.9573 5.18 0.07717 43.06017
0.490 42.56 1.791567 6.19 0.096 81.34
0.227 15.32 1.674467 5.3 0.063 10.47
0.302 22.68 1.562867 5.18 0.073 76.86
0.417 52.08 1.670433 4.75 0.098 79.98
0.392 49.43 1.608467 4.57 0.095 88.72
0.441 53.15 1.674 5.12 0.101 73.85
0.44595 33.38476 . 6.61 0.146 104.96
0.24467 17.2852 . 5.56 0.123 21.45
0.29489 17.78717 . 5.39 0.136 119.75
0.33835 32.95005 . 4.91 0.16085 99.12
0.31672 31.94973 . 4.74 0.18162 88.43
0.38775 35.20741 . 5.44 0.16518 110.3

proc corr;
var ndvi buac gn ph sn sp;
run;


B.  coefficient of determination (R2), correlation coefficient (R)
proc glm;
model buac = ndvi;
run;

C.  r versus R (simple regression versus multiple regression)

proc glm;
model buac = ndvi ph sn;
run;


R2  (percent of the variability in y explained by x)



Applied Procedures
    Proc Plot (proc plot; plot y * x = "*";
    Proc Means (var statement)  
    Proc corr (var statement)

RCBD vs CRD
Contrasts (orthogonal contrast coefficients)
Contrasts for Unequal Treatment Spacing


Covariance and Autocorrelation

Regression Analysis

Proc Mixed Example Using 502 Data

(PPT file, WEB analysis of Proc Mixed)

Added Class Program

data one;
input year rep trt buac;
cards;
2011  1     1     29.13
2011  1     2     22.44
2011  1     3     37.07
2011  1     4     34.88
2011  1     5     38.15
2011  1     6     35.15
2011  1     7     34.83
2011  1     8     48.58
2011  1     9     35.77
2011  1     10    37.86
2011  1     11    47.26
2011  1     12    48.48
2011  1     13    47.89
2011  1     14    38.62
2011  2     1     25.52
2011  2     2     29.42
2011  2     3     30.32
2011  2     4     41.71
2011  2     5     45.88
2011  2     6     47.45
2011  2     7     48.13
2011  2     8     41.68
2011  2     9     49.90
2011  2     10    42.09
2011  2     11    47.43
2011  2     12    50.31
2011  2     13    46.97
2011  2     14    47.57
2011  3     1     33.32
2011  3     2     29.50
2011  3     3     24.72
2011  3     4     41.12
2011  3     5     23.69
2011  3     6     50.76
2011  3     7     54.57
2011  3     8     45.64
2011  3     9     24.64
2011  3     10    48.06
2011  3     11    53.34
2011  3     12    21.19
2011  3     13    17.13
2011  3     14    46.13
2011  4     1     29.12
2011  4     2     28.70
2011  4     3     29.06
2011  4     4     27.45
2011  4     5     33.33
2011  4     6     28.41
2011  4     7     41.24
2011  4     8     44.58
2011  4     9     48.67
2011  4     10    31.52
2011  4     11    46.24
2011  4     12    40.51
2011  4     13    33.24
2011  4     14    46.06
2012  1     1     23.96
2012  1     2     18.55
2012  1     3     37.45
2012  1     4     43.08
2012  1     5     54.32
2012  1     6     57.85
2012  1     7     63.22
2012  1     8     50.38
2012  1     9     49.44
2012  1     10    49.20
2012  1     11    62.95
2012  1     12    62.23
2012  1     13    61.34
2012  1     14    52.85
2012  2     1     22.94
2012  2     2     28.51
2012  2     3     31.36
2012  2     4     49.26
2012  2     5     57.01
2012  2     6     60.81
2012  2     7     56.56
2012  2     8     53.39
2012  2     9     55.71
2012  2     10    57.79
2012  2     11    57.23
2012  2     12    63.18
2012  2     13    59.13
2012  2     14    63.15
2012  3     1     27.02
2012  3     2     28.27
2012  3     3     39.78
2012  3     4     47.45
2012  3     5     61.44
2012  3     6     62.07
2012  3     7     62.97
2012  3     8     59.45
2012  3     9     60.86
2012  3     10    52.64
2012  3     11    56.36
2012  3     12    61.55
2012  3     13    64.25
2012  3     14    53.68
2012  4     1     29.34
2012  4     2     32.97
2012  4     3     32.03
2012  4     4     53.80
2012  4     5     48.77
2012  4     6     61.87
2012  4     7     62.15
2012  4     8     47.33
2012  4     9     53.83
2012  4     10    60.89
2012  4     11    57.85
data two; set one;
proc sort; by year;
proc glm; by year;
  class rep trt;
  model buac = rep trt;
  means trt/duncan;
proc glm;
  class year rep trt;
  model buac = year rep(year) trt year*trt;
  test h = year e = rep(year);
means year trt year*trt;
run;

data four; set one;  proc sort; by year rep trt;
data five; set three; proc sort; by year rep trt;

data six; merge four five; by year rep trt;
proc print;

502 Update Program (excel file) go to Mean_SD

Site from 2001  (added programs)