Stability of Sources of Resistance to Cowpea Aphid (Aphis craccivora Koch, Hemiptera: Aphididae) across Major Cowpea Production Zones in Ghana

Table 6

Effect of aphid infestation on grain yield of cowpea cultivars/genotypes.

Cultivar/genotype	Grain yield (kg)/ha			95% CI of mean difference (infested–uninfested)
	Uninfested	Infested	% yield loss
Apagbaala	897 ± 250.62	625 ± 152.54	30.3	−423.8–120.7
SARC1-57-2	850 ± 70.27	808 ± 129.10	4.9	−101.0–17.7 ns
SARC1-91-1	850 ± 237.39	767 ± 149.17	9.8	−141.9–24.8
IT97K-499-35 (Songotra)	814 ± 231.70	675 ± 132.80	17.1	−227.8–49.93
Zaayura	775 ± 100.62	569 ± 432.73	26.6	−277.8–133.3
Resistant BC4F3 (Zaayura//(Zaayura × SARC1-57-2))	936 ± 185.71	900 ± 208.24	3.8	−104.7–32.5 ns
Susceptible BC4F3 (Zaayura//(Zaayura × SARC1-57-2))	806 ± 66.90	542 ± 199.15	32.8	−396.8–131.0
IT99K-573-1-1	806 ± 102.42	547 ± 90.44	32.1	−461.3–55.3
IT99K-573-3-2-1	803 ± 221.68	586 ± 119.15	27.0	−305.2–128.2
Padituya	1086 ± 440.72	911 ± 284.16	16.1	−400.0–50.0 ns
Mean	862.3	693

Note. Data are means ± standard error of means; CI = confidence interval. CI of mean difference is significant at 5% probability threshold level (i.e., mean differences that do not include zero are significantly different).