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

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Francis Kusi ◽  
Jerry A. Nboyine ◽  
Patrick Attamah ◽  
Justice F. Awuku ◽  
Issa Sugri ◽  
...  
Keyword(s):  
Yield Loss ◽  
Aphis Craccivora ◽  
Seedling Stage ◽  
Yield Losses ◽  
Sources Of Resistance ◽  
Aphid Infestation ◽  
Resistant Cultivars ◽  
Cowpea Aphid ◽  
Aphis Craccivora Koch ◽  
The Stability

Aphids (Aphis craccivora Koch) are an important vegetative stage pest of cowpea in Africa. The use of resistant cultivars is among the best management option for this pest, but the success of this strategy is influenced by the stability of the resistant genotype to the cowpea aphid biotypes present in the major cowpea growing areas in a country. This work, therefore, aimed at identifying cultivars/genotypes with stable resistance to aphid infestation across different cowpea growing ecologies in Ghana and estimating yield loss due to aphid infestation at the seedling stage. To ascertain the stability of aphid-resistant cultivars/genotypes, four cultivars/genotypes (SARC1-57-2, SARC1-91-1, IT97K-499-35, and Zaayura) and a susceptible check (Apagbaala) were tested across 18 locations in Ghana. An on-station experiment was used to quantify yield losses due to aphid attack at the seedling stage in the five cultivars/genotypes mentioned above together with 5 additional cultivars/genotypes [i.e., IT99K-573-3-2-1, IT99K-573-1-1, Padituya, Resistant BC4F3 (Zaayura//(Zaayura × SARC1-57-2)), and Susceptible BC4F3 (Zaayura//(Zaayura × SARC1-57-2))]. The results showed that SARC1-57-2 was stable in all ecologies, in terms of its resistance to aphids; it had high vigour score (3.8 ± 0.03) and low plant mortality (3.7 ± 0.22%) compared to the susceptible genotypes. The number of days to flowering and maturity were significantly higher in aphid-infested plants than in the uninfested ones. Grain yield loss was estimated to range between 3.8 and 32.8%. Except for SARC1-57-2, Resistant BC4F3, and Padituya, the remaining cultivars/genotypes sustained significant yield losses under aphid infestation. Thus, the aphid-resistance gene in SARC1-57-2 is stable against aphids. This resistance genotype can be incorporated into cowpea improvement programmes to breed for aphid-resistant cultivars. Also, the cultivation of such improved cultivars will reduce pesticide usage in cowpea production.

scholarly journals Relative Abundance and Yield Loss Assessment of Lentil Aphid, Aphis craccivora Koch in Relation to Different Sowing Dates

1970 ◽  
Vol 4 (1) ◽  
pp. 101-106 ◽  
Author(s):  
Md. Altaf Hossain ◽  
Jannatul Ferdous ◽  
MMR Salim
Keyword(s):  
Relative Abundance ◽  
Yield Loss ◽  
Aphis Craccivora ◽  
Aphid Population ◽  
Loss Assessment ◽  
Protection Measures ◽  
Aphid Infestation ◽  
Yield Loss Assessment ◽  
Sowing Dates ◽  
Aphis Craccivora Koch

Relative abundance of lentil aphid, Aphis craccivora Koch were investigated and yield loss assessment at different sowing dates during rabi season of 1999-2000 and 2000-2001 at Ishurdi Bangladesh. Lentil aphid appeared in field in the first week of January. The maximum aphid population (15.82/twig) was recorded in the first week of February 2000-2001, but the population reached to the peak was in the last week of January in 1999-2000, subsequently rainfall caused a sudden reduction of aphid population in latter dates. Aphid population and infestation increased with the delayed dates of sowing. The crop sown in November received less aphid infestation and consequently produced higher yield than the crop sown in December. During 1999-2000, the avoidable yield loss due to aphid infestation was recorded 0.90 to 6.78% and in 2000-2001 it was 2.65 to 9.00% depending on the different dates of sowing. Avoidable yield loss was less in November sowing crop than the crop sown in December. On the other hand, yield increased by 0.91 to 7.27% and 2.72 to 9.89% in 1999-2000 and 2000-2001 respectively, due to protection measures taken against aphids and this was also depend on different dates of sowing. Key words: Lentil aphid, delayed sowing, infestation, yield.

Resistance to Hessian fly (Diptera: Cecidomyiidae) in a Canadian spring wheat cultivar

2006 ◽  
Vol 138 (5) ◽  
pp. 638-646 ◽  
Author(s):  
Ian L. Wise ◽  
Robert J. Lamb ◽  
Ronald I.H. McKenzie ◽  
Jay W. Whistlecraft
Keyword(s):  
Spring Wheat ◽  
Partial Resistance ◽  
Yield Loss ◽  
Wheat Cultivar ◽  
Hessian Fly ◽  
Seedling Stage ◽  
Susceptible Cultivar ◽  
Wheat Cultivars ◽  
Yield Losses ◽  
Spring Wheat Cultivar

AbstractThe Canadian spring wheat (Triticum aestivum L.; Poaceae) cultivar ‘Superb’ was less susceptible to damage by Hessian fly, Mayetiola destructor (Say), than the spring wheat cultivars ‘AC Barrie’, ‘AC Foremost’, ‘McKenzie’, ‘AC Domain’, and ‘Glenlea’ in Manitoba. The partial resistance of ‘Superb’ was similar, at the seedling stage, to that of ‘Guard’, which possesses the resistance gene H18. Females laid eggs readily on all cultivars, providing no evidence for antixenosis, but few larvae developed on seedlings of ‘Superb’ and ‘Guard’, showing that antibiosis against larvae is the mechanism of resistance in these seedlings. In the field, where infestation of spring wheat takes place about 4 weeks after the seedling stage, ‘Guard’ continued to show high levels of resistance, but ‘Superb’ was less resistant, although still more resistant than highly susceptible cultivars. Infested stems of ‘Superb’ and ‘Nordic’ were less likely to break than infested stems of other cultivars, showing that these two cultivars are partially tolerant to infestation. Infested stems of ‘Guard’ and other cultivars showed high levels of stem breakage and are intolerant. Yield losses due to infestation by Hessian fly were mostly caused by the breakage and falling over of infested stems, which prevented the seeds on these stems from being harvested. Infested stems of all susceptible cultivars that remained standing at harvest had lower seed masses and fewer seeds per spike than uninfested stems, which contributed to yield loss. ‘Grandin’, a parent of ‘Superb’, is the probable source of resistance in ‘Superb’, but the pedigree of ‘Grandin’ provides no clue as to the gene(s) involved. The partial antibiosis and tolerance expressed by ‘Superb’ is sufficient to reduce losses to Hessian fly by 65% in comparison with a susceptible cultivar such as ‘AC Barrie’. ‘Superb’ is the first Canadian spring wheat cultivar identified to have an agronomically useful level of resistance to Hessian fly.

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