Grain Yield and Path Analysis in the Evaluation of Cowpea Landraces

Abstract

Cowpea is a staple food in the Northeast of Brazil, thus, genetic improvement of this species is important. Samples of cowpea landraces were collected in the State of Rio Grande do Norte, Brazil, and the most promising ones were evaluated in the present study. The objective was to identify the most productive varieties and the characteristics that have greater direct effect on grain yield, for breeding purposes. Twelve landraces were evaluated using a randomized block design with five replications, in two experiments-one in the dry season, and other in the rainy season. However, water irrigation was used in both experiments, due to the almost total absence of rainfall in the rainy season. The Baraúna, and Carnaubais cowpea varieties were the most productive in both experiments. Campo Grande was the best variety found in the experiment carried out in the dry season. José da Penha, Lagoa de Pedra, Umarizal, and Upanema were the best varieties in the experiment carried out in the rainy season. The number of pods per plant was the characteristic that had greater direct effect on grain yield. RENDIMENTOS DE GRÃOS E ANÁLISE DETRILHA NA AVALIAÇÃO DE VARIEDADES TRADICIONAIS DE FEIJÃO-CAUPI RESUMO -O feijão-caupi é uma das principais culturas alimentícias do Nordeste brasileiro e, por essa razão, existe interesse em melhorá-la geneticamente. Foram coletadas variedades tradicionais dessa cultura no Estado do Rio Grande do Norte e as mais promissoras foram avaliadas no presente trabalho. Objetivou-se identificar as mais produtivas e distinguir, entre as características avaliadas, a que possui o maior efeito direto sobre o rendimento de grãos, para fins de melhoramento. Doze variedades foram avaliadas em blocos ao acaso com cinco repetições em dois experimentos. Um dos experimentos foi irrigado. O outro experimento foi realizado na época das chuvas, mas requereu irrigação devido à ausência quase que total de chuvas. As variedades Baraúna e Carnaubais foram as mais produtivas nos dois experimentos. No experimento realizado com irrigação foi destaque a variedade Campo Grande. Sob condições de sequeiro (com chuvas) destacaram-se também as variedades José da Penha, Lagoa de Pedra, Umarizal e Upanema. O número de vagens por planta foi o principal caráter a influenciar o rendimento de grãos. Palavras-chave: Vigna unguiculata. Variedades crioulas. Feijão-de-corda. Feijão macassar. Componentes do rendimento.

Evaluation of Cowpea Landraces under a Mediterranean Climate

“…The average seed yield achieved during our study ranged from 0.39-1.05 t ha −1 and was therefore lower than the average seed yield reported for Greek conditions. The observed seed yield values were also lower than the average seed yield of cowpea landraces reported in other countries, such as in Ethiopia (2.05 t ha −1 ) and Brazil (1.05 t ha −1 ) [75,76]. Statistically significant differences have been recorded for cowpea landraces originated from Southern European countries regarding their seed yield, which ranged from 0.66 g m −2 to 3.12 g m −2 among three experimental locations and two experimental years [1].…”

Association Mapping for Drought Tolerance and Yield-Related Traits in Cowpea Accessions

“…From the study chromosomes 1, 2, 3, 5, 6, 7, 8, 9, 10 and 11 have the most important genetic information and traits with regards to drought tolerance at seedling stage in the screen houses. (19). Thus the PWT trait was more pronounced in the glasshouse with more chromosomes exhibiting the trait than in the greenhouse.…”

Cowpea Constraints and Breeding in Europe

“…Cowpea yield is strongly affected by environment (E) and genotype x environment interaction (G × E) [ 193 , 296 , 297 , 298 , 299 , 300 ] ( Table 6 ). Identification of high-seed-yielding genotypes with broad adaptability and therefore yield stability [ 301 ] is considered one of the primary improvement goals [ 302 ] in Europe as in the rest of the world.…”

“…Numerous landraces have been screened for their seed and fresh pod yield performance under adverse environments [ 296 , 330 , 331 , 332 , 333 ]. Among landraces evaluated, some were proved to yield similarly to improved genotypes, such as the “Akidi Ala” local variety from Nigeria and “Chimponogo” local variety from Zambia [ 334 , 335 ].…”