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Breeding and Selection for Drought Resistance traditional , late-flowering cowpea varieties from West Africa still need to be evaluated.
Hall, A.E.; Patel, P.N. Breeding for resistance to drought and heat . In : Cowpea research, production and utilization edited by S.R. Singh and K.O. Rachie. 137-151 . Chichester, England, John Wiley. 1985.
143 Yadava, R.B.R. ; PaW, B.D. Screening of cowpea (Vigna unguiculata L.) var ieties for drought tolerance . Journal of Plant Breeding, 93(3): 259-262 . 1984.
Drought and high temperatures often occur together in the sem i-arid zones where cowpeas are grown and they have interactive adverse eff ects on plant growth and development. Studies on cowpea responses to temperature showed that high temperatures at night can be much more damaging to grain yield of cowpeas than high temperatures during the day. Crosses have been made to transfer heat tolerance from one cultivar to another. It has been observed that several cowpea strains developed by empirical breeding procedures in one of the hottest cowpea-production regions of the world have some tolerance to high night temperatures . But the heat tolerance of
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Eight varieties of cowpea (Vigna unguiculata L) were screened for drought tolerance. HFC-42 -1 and IGFRI -450 showed lower CSI values under drought in comparison to other tested varieties, but the values of relative water content (RWC) and diffusion pressure deficit (DPD) were higher. These indices allow us to consider that of the varieties tested HFC-42-1, lGFRI-450 and IGFRI-457 are the comparatively more drought tolerance varieties of cowpea. There was direct relationship between chlorophyll stability index (CSI) and reduction in yield.
Breeding and Selection for Insect Resistance Bosque-Perez, N.A.; Leigh, T.F.; FQster, K.W.; Duffey, S.S. Nymph growth and development, ov iposition, and seed damage on cowpea by Lygus hesperus (Heteroptera: Miridae). Journal of Economic Entomology 78(6) : 1254-1258. 1985.
Blackeye 5' (CBS). The two genotypes exerting greatest reduction on nymph growth were PI 170861 and PI 148674. Oviposition by Iygus bugs was Significantly lower on 'KR78 -3-2' and PI 367925 than on 'CBS'. Mean numbers of seeds damaged by Iygus bugs were Significantly lower for the cowpea acquisitions 'New Era', PI 227829. and 'CR 17-1 -13' than for 'CBS' in both free-choice and no-choice experiments. Several of these cowpea acquisitions appear to be good genetic sources for developing improved varieties with resistance to Iygus bugs.
I
Twenty cowpea genotypes were tested for resistance to Lygus hesperus. During 1982, the effect of these genotypes on nymph survival and growth, and ov ipositional preference was measured. Susceptibility of the 20 genotypes to Lygus -induced seed damage was also measured in both natural field and caged adult female fnfestatiOl.s. Nymph growth and seed damage were evaluated again in 1983_ Significant reductions in nymph growth were measured on 8 of the 20 entries when compared with the susceptible standard 'California
145 Caswell, G.H. The value of the pod in protecting cowpea seed from attack by bruchid beetles. Samaru Journal of Agricultural Research, 2(112): 4955. 1984
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