This report describes standardized data for “Cowpea Yield Evaluation Trials - Gummel, 1992 - 1995”. These data were standardized on 2024-09-20 by Robert Hijmans with this R script. The original data have a CC-BY license. Here you can download the standardized data.

This is the full citation of the data set:

Boukar, Ousmane; Christian Fatokun (1991). Cowpea Yield Evaluation Trials - Gummel, 1992 - 1995. International Institute of Tropical Agriculture (IITA). Not versioned. doi:10.25502/20180817/1124/BO

The dataset has 2412 records and 21 variables for cowpea in Nigeria. The dataset has 1 treatment(s): variety.


These are the first 25 records:

records
trial_id planting_date harvest_date on_farm is_survey rep crop variety yield_part yield N_fertilizer P_fertilizer K_fertilizer irrigated country location longitude latitude geo_from_source
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 1 cowpea IT92KD-404-1 seed 31.25 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 1 cowpea IT89KD-391 seed 62.50 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 1 cowpea IT92KD-372-1-2 seed 250.00 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 1 cowpea IT88DM-363 seed 390.63 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 1 cowpea IT88D-365 seed 406.25 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 1 cowpea IT90K-277-2 seed 109.38 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 1 cowpea IT94K-2332-5 seed 31.25 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 1 cowpea IT89KD-374 seed 250.00 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 1 cowpea DANILA seed 62.50 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 1 cowpea IT90K-109 seed 187.50 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 2 cowpea IT88DM-363 seed 62.50 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 2 cowpea IT90K-109 seed 93.75 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 2 cowpea IT92KD-404-1 seed 31.25 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 2 cowpea IT89KD-391 seed 156.25 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 2 cowpea IT92KD-372-1-2 seed 62.50 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 2 cowpea IT88D-365 seed 93.75 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 2 cowpea IT94K-2332-5 seed 93.75 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 2 cowpea IT89KD-374 seed 156.25 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 2 cowpea DANILA seed 93.75 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 2 cowpea IT90K-277-2 seed 31.25 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 3 cowpea IT89KD-374 seed 187.50 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 3 cowpea DANILA seed 125.00 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 3 cowpea IT90K-277-2 seed 93.75 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 3 cowpea IT94K-2332-5 seed 62.50 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE
AD1295GUMEL 1992-05-15 1995-09-30 FALSE FALSE 3 cowpea IT89KD-391 seed 125.00 NA NA NA NA Nigeria Gummel 9.38396 12.62261 TRUE


The observations are for 1 locations, for which we have 1 unique mapped locations.


The standardization script emits the following non-compliance warnings.

message
2412 harvest_date more than 366 days after planting_date

The overall quality of the dataset, given the completeness of required variables was 5.6 on a scale of 10. See the table below

variable completeness (%)
planting_date 100
harvest_date 100
N_fertilizer 0
P_fertilizer 0
K_fertilizer 0
irrigated 0
latitude 100
longitude 100
location 100


The data are further summarized in the table below.

Variable Stats / Values Freqs (% of Valid) Graph Missing
trial_id [character]
1. STUDY 715
2. PM392GM
3. STUDY 706
4. STUDY 735
5. AD192GMB
6. AD194GUMEL
7. AD195GUMEL
8. AD294GUMEL
9. AD395GUMEL
10. AD495GUMEL
[ 27 others ]
150(6.2%)
120(5.0%)
90(3.7%)
88(3.6%)
80(3.3%)
80(3.3%)
80(3.3%)
80(3.3%)
80(3.3%)
80(3.3%)
1484(61.5%)
 0 (0.0%)
planting_date [character] 1. 1992-05-15
2412(100.0%)
 0 (0.0%)
harvest_date [character] 1. 1995-09-30
2412(100.0%)
 0 (0.0%)
on_farm [logical] 1. FALSE
2412(100.0%)
 0 (0.0%)
is_survey [logical] 1. FALSE
2412(100.0%)
 0 (0.0%)
rep [integer]
Mean (sd) : 1.8 (1.7)
min ≤ med ≤ max:
-3 ≤ 2 ≤ 4
IQR (CV) : 2 (1)
-3:92(4.1%)
-2:104(4.6%)
-1:84(3.7%)
1:560(24.9%)
2:559(24.8%)
3:559(24.8%)
4:293(13.0%)
 161 (6.7%)
crop [character] 1. cowpea
2412(100.0%)
 0 (0.0%)
variety [character]
1. DANILA
2. IT91K-118-20
3. IT90K-109
4. KANANNADO
5. IT90K-284-2
6. IT89KD-288
7. IT89KD-391
8. IT90K-277-2
9. IT89KD-374-57
10. IT84S-2246-4
[ 514 others ]
41(1.7%)
32(1.3%)
29(1.2%)
29(1.2%)
28(1.2%)
27(1.1%)
27(1.1%)
27(1.1%)
26(1.1%)
25(1.0%)
2121(87.9%)
 0 (0.0%)
yield_part [character] 1. seed
2412(100.0%)
 0 (0.0%)
yield [numeric]
Mean (sd) : 703 (583.3)
min ≤ med ≤ max:
0 ≤ 601.2 ≤ 3674
IQR (CV) : 835.8 (0.8)
 1096 distinct values 135 (5.6%)
N_fertilizer [logical]
All NA's
 2412 (100.0%)
P_fertilizer [logical]
All NA's
 2412 (100.0%)
K_fertilizer [logical]
All NA's
 2412 (100.0%)
irrigated [logical]
All NA's
 2412 (100.0%)
country [character] 1. Nigeria
2412(100.0%)
 0 (0.0%)
location [character] 1. Gummel
2412(100.0%)
 0 (0.0%)
geo_from_source [logical] 1. TRUE
2412(100.0%)
 0 (0.0%)