Ordinal regression model for pea seed mass

Figures & Tables

Model component	Variable level	Estimate	Standard error	Wald	df	Significance	95% Confidence interval

							Lower bound	Upper bound
Threshold	[1] < 200 mg	−0.824	0.054	232.6	1	<0.001	−0.930	−0.718
	[2] 200–240 mg	−0.303	0.051	35.2	1	<0.001	−0.403	−0.203
	[3] 240–270 mg	0.232	0.052	19.6	1	<0.001	0.129	0.335
	[4] 270–300 mg	1.045	0.059	311.1	1	<0.001	0.929	1.161

Location	[Seeds per pod]	0.056	0.008	50.9	1	<0.001	0.041	0.072
	[Pods per plant]	0.048	0.010	22.2	1	<0.001	0.028	0.068
	[Seeds per plant]	−0.006	0.002	9.7	1	<0.002	−0.010	−0.002
	[Year = 2010]	−0.849	0.030	796.2	1	<0.001	−0.908	−0.790
	[Year = 2011]	0.000	.	.	0	.	.	.
	[Cultivar = Klif]	−0.727	0.028	691. 7	1	<0.001	−0.781	−0.673
	[Cultivar = Tarchalska]	0.000	.	.	0	.	.	.
	[IUNG = 1]	0.081	0.022	13.7	1	<0.001	0.038	0.125
	[Nitragina = 2]	0.038	0.023	2.9	1	0.088	−0.006	0.083
	[Control = 3]	0.000	.	.	0	.	.	.

Scale	[Cultivar = Klif ]	−0.621	0.029	448.2	1	<0.001	−0.678	−0.563
	[Cultivar = Tarchalska]	0.000	.	.	0	.	.	.
	[Year = 2010]	−0.492	0.031	246.6	1	<0.001	−0.553	−0.430
	[Year = 2011]	0.000	.	.	0	.	.	.

	Years	April	May	June	July	August
Temperature (°C)	2010	7.5	11.7	16.7	20.4	18.5
	2011	9.7	13.2	17.4	17.3	18.9
	Long-term mean	8.1	13.7	16.5	18.2	17.9
Rainfall (mm)	2010	66.5	193.2	103.5	208.5	95.1
	2011	29.2	71.5	99.5	167.5	73.2
	Long-term mean	50.2	65.3	80.0	74.9	78.5

	Seed mass	Seeds	Pods	Seeds
	(mg)	(per pod)	(per plant)	(per plant)
Year
2010	210^b	2.45^b	6.82^b	28.3^b
2011	270^a	2.88^a	7.18^a	33.5^a
Cultivar
Tarchalska	270^a	2.55^b	6.50^b	27.4^b
Klif	220^b	2.76^a	7.42^a	33.9^a
Inoculant
IUNG	250^a	2.87^a	7.30^a	33.2^a
Nitragina	240^a	2.69^b	6.86^b	30.6^b
Control	260^a	2.45^c	6.85^b	29.1^c

Model	−2 Log likelihood	Chi-square	df	Significance
Intercept only	10,564.1
Final model	7,338.1	3,226.0	9	0.000