Profitability of positive selection technique for seed yam production in Ghana and Nigeria

Figures & data

Figure 1. Map of Ghana showing the study area.

Figure 2. Map of Nigeria showing the study area.

Table 1. Frequency distribution of farmer characteristics

Variable^2	Ghana				Nigeria				ALL
	PS^†		Non-PS^††		PS		Non-PS		PS		Non-PS
	Freq	%	Freq	%	Freq	%	Freq	%	Freq	%	Freq	%
Sex
Male	58	66.7	51	64.6	57	71.3	50	59.5	115	68.9	101	62
Female	29	33.3	28	35.4	23	28.8	34	40.5	52	31.1	62	38
Level of Education
None	41	47.1	49	62	18	22.5	10	11.9	59	35.3	59	36.2
Basic	37	42.5	22	27.8	29	36.3	36	42.9	66	39.5	58	35.6
Quranic	0	0	0	0	1	1.3	1	1.2	1	0.6	1	0.6
Secondary	7	8	7	8.9	22	27.5	25	29.8	29	17.4	32	19.6
Tertiary	2	2.3	1	1.3	10	12.5	12	14.3	12	7.2	13	8
Primary Occupation
Farmer	87	100	79	100	68	85	70	83.3	155	92.8	149	91.4
Traders	0	0	0	0	3	3.8	7	8.3	3	1.8	7	4.3
Civil Servants	0	0	0	0	4	5	3	3.6	4	2.4	3	1.8
Craft	0	0	0	0	5	6.3	4	4.8	5	3	4	2.5
Nativity
Natives	46	52.9	57	72.2	67	83.8	75	89.3	113	67.7	132	81
Non-natives	41	47.1	22	27.8	13	16.3	9	10.7	54	32.3	31	19

Source: Field survey, 2018

Table 2. Descriptive statistics on farmer characteristics

Variable^3	Ghana				Nigeria				ALL
	PS^†		Non-PS^††		PS		Non-PS		PS		Non-PS
	Mean	SD^œ	Mean	SD	Mean	SD	Mean	SD	Mean	SD	Mean	SD
Education (years)	3	4.59	4	4.82	7	5.04	8	4.96	5	5.14	6	5.25
Household size (Number)	8	4.18	9	4.95	9	6.09	8	5.26	9	5.19	9	5.10
Experience (years)	18	12.54	19	13.28	19	11.99	19	11.36	19	12.27	19	12.29
Ware yam farm size (ha)	0.74	0.50	0.59	0.35	1.53	1.24	1.15	0.85	1.12	1.01	0.88	0.71
Extension contact (Number)	7	5.34	7	4.138	8	7.119	8	8.036	8	6.26	7	6.44

Source: Field survey, 2018

Table 3. Average output(t/ha) for treatment⁴

Location		N	Minimum	Maximum	Mean	SD^œ
GHANA	PS^†	87	2.88	7.27	5.12	0.98
	Non-PS^††	79	1.33	7.11	4.43	1.04
NIGERIA	PS	80	3.76	7.50	5.56	0.99
	Non-PS	84	1.13	6.70	4.41	1.02
ALL	PS	167	2.88	7.50	5.33	1.01
	Non-PS	163	1.13	7.11	4.42	1.02

Source: Field Survey, 2018.

Table 4. Seed yam total variable costs (US$/ha)

Cost Item^5	Ghana		Nigeria		ALL
	PS^†	Non-PS^††	PS	Non-PS	PS	Non-PS
Seed	502.72	519.79	511.32	505.91	506.84	512.64
Insecticide	20.41	20.67	23.38	22.86	21.83	21.79
Fungicide	22.47	22.78	34.28	35.01	28.13	29.08
Neem powder	157.97	170.15	439.24	424.53	292.71	301.24
Labor	4945.99	5210.16	5271.90	4863.88	5102.11	5031.71
Total variable Costs (TVC)	5649.55^NS	5943.55	6280.11 ^NS	5852.18	5951.62 ^NS	5896.46

Source: Field Survey, 2018.

Table 5. Percentage distribution of TVC^§

Variable Input^6	GHANA		NIGERIA		ALL
	PS^†	Non-PS^††	PS	Non-PS	PS	Non-PS
Seed	8.90	8.75	8.14	8.64	8.52	8.69
Insecticide	0.36	0.35	0.37	0.39	0.37	0.37
Fungicide	0.40	0.38	0.55	0.60	0.47	0.49
Neem leaf	2.80	2.86	6.99	7.25	4.92	5.11
Labor	87.55	87.66	83.95	83.11	85.73	85.33
TVC	100		100	100	100	100

Source: Field Survey, 2018

Table 6. TFC⁷ (US $) for seed yam production

	GHANA		NIGERIA		ALL
Fixed Input	PS	Non-PS	PS	Non-PS	PS	Non-PS
Land	42.29	43.39	40.39	40.57	41.38	41.94
Cutlass	10.27	12.21	8.66	8.17	8.87	9.40
Hoe	7.63	8.82	24.42	23.75	15.68	16.51
TFC	60.18^NS	64.42	73.47^NS	72.48	65.93^NS	67.85

Source: Field Survey, 2018.

Table 7. Profitability of seed yam production in Ghana and Nigeria⁸

	GHANA		NIGERIA		ALL
	PS^†	Non-PS^††	PS	Non-PS	PS	Non-PS
Revenue
Output (t/ha)	5.12	4.43	5.56	4.41	5.3306	4.42
Price/t (US$)	1740.55	1778.02	1802.17	1734.27	1770.069	1755.47
Total Revenue (TR)	8909.35*	7875.57	10,021.88***	7651.42	9435.53***	7759.90
Variable Cost (VC)
Seed	502.72	519.79	511.32	505.91	506.84	512.64
Insect	20.41	20.67	23.38	22.8589	21.8329	21.79
Fungi	22.47	22.77	34.277	35.01	28.13	29.08
Neem	157.967	170.153	439.237	424.53	292.71	301.24
Labor	4945.99	5210.16	5271.9	4863.88	5102.11	5031.70
TVC	5649.55	5943.55	6280.11	5852.18	5951.62	5896.46
Gross Margin (GM)	3259.79*	1932.01	3741.77***	1799.25	3483.91***	1863.44
Fixed Cost
Land	42.29	43.39	40.39	40.57	41.38	41.94
Cutlass	10.27	12.21	8.66	8.17	8.87	9.40
Hoe	7.63	8.82	24.48	23.74	15.68	16.51
TFC	60.18	64.43	73.48	72.48	65.92	67.85
Total Cost (TC)	5709.74	6007.98	6353.59	5924.67	6017.55	5964.31
Net Return (NR)	3199.61*	1867.59	3668.29***	1726.77	3417.98***	1795.58
Benefit Cost Ratio (BCR)	1.56	1.31	1.58	1.29	1.57	1.30
Return on Investment (ROI)	56.04	31.09	57.74	29.15	56.80	30.11

Source: Field Survey, 2018.

*.**, and ***, indicate significance at the 10%, 5%, and 1% levels, respectively.

Table 8. Determinants of profitability in quality seed yam production

Variable	Ghana		Nigeria		ALL
	Coefficient	SE	Coefficient	SE	Coefficient	SE
Sex	0.101***	0.043	0.220***	0.022	0.253***	0.091
Experience	0.248**	0.033	0.422***	0.090	0.373**	0.221
Edu	0.449**	0.053	0.710**	0.202	0.229***	0.019
Native	0.621	0.075	0.401**	0.053	0.346**	0.056
Ext	0.304**	0.066	0.307***	0.055	0.841***	0.068
Household labor	0.960	0.507	0.453	0.608	0.394	0.840
Off farm Income	0.134***	0.040	0.533***	0.030	0.728***	0.045
Positive Selection	0.087***	0.022	0.529***	0.060	0.194***	0.067
Constant	0.788*	0.091	0.572	0.528	0.881	0.577
N	166		164			330
F-Stat	5.82***		5.01***			5.41
R^2	67.5		65.2			66.3

Source: Field Survey, 2018. SE denotes standard errors. The asterisks, ^{*, **,} and ***, indicate significance at the 10%, 5% and 1%