Desempenho agronômico e heterose de genótipos de cebola

Abstract

Agronomic performance and heterosis of onion genotypesThe use of onion hybrids in Brazil is still recent, with little information regarding the gains from heterosis. However, the first step to exploit the heterosis is the evaluation of available germplasm. Due to the need for genotypes adapted to the climatic conditions of South-Central region of Paraná state, Brazil, this study aimed to evaluate the agronomic performance of 19 hybrids and 50 inbred lines of onion, as well as the heterotic gain of six of these hybrids. The experimental design was randomized blocks with three replications. The evaluated traits were yield, average weight of the bulbs, commercial classification of bulbs, waxy of the leaves and cycle. In general the hybrids were superior to the lineages in yield and average bulb weight and had lower cycle. The heterotic gain in hybrids was evident, indicating the viability of hybrids for cultivation in the region. Hybrids 2572, 2573 and 2578 are promising due their high yield, earliness cycle and better classification of the bulbs. The lineages 2507-1 and 2983 provided the highest heterotic gain for the yield of the hybrid 2857, which was classified in the group of earliest genotypes, showing an inverse correlation between these two characters.

Agronomic performance of onion hybrids in Baraúna, in the semi-arid region of Brazil

“…The Serena F1 hybrid was the most productive (78,670 kg ha -1 ) and did not significantly differ from the Mata Hari cultivar, which produced 76,290 kg ha -1 (Table 2). Despite achieving high yields as a result of the level of technology adopted, these values are consistent with those observed by Faria et al (2012) and Baier et al (2009) Souza et al (2008), who assert that the cultivars of IPA, Alfa San Francisco and Alfa Tropical series should be recommended for the northeast.…”

“…According to Faria et al (2012), the consumption of onions in Brazil in recent years is practically steady at between 750,000 and 850,000 tonnes per year. Of this total, the country has imported between 75,000 and 330,000 tonnes annually, a volume that varies according to the reduction in domestic supply, whether due to adverse climatic conditions or to being less competitive in the market due to the low classification and standardisation of the Brazilian onion.…”

“…However, the use of hybrids in the domestic market is still new, with little information concerning the agronomic response of the hybrids and strains to be used in crossings (FARIA et al, 2012).…”

Adaptabilidade e estabilidade fenotípica de genótipos de cebola em regiões produtoras do Estado de São Paulo

“…Se as condições não satisfizerem as exigências da cultura podem haver perdas na produtividade, redução da bulbificação, emissão precoce do pendão floral, formação de "charutos" e de bulbos pequenos [20]. Segundo Kopsell & Randle (1997) [15], citado por Faria et al (2012) [9], além destes fatores, cuidados com a adubação, época de plantio, colheita, irrigação e escolha da cultivar devem ser tomados.…”

“…A avaliação da interação genótipos x ambientes e das técnicas para sua análise vêm sendo utilizadas em várias oleráceas [9]. Em cebola, esta avaliação é de grande interesse, uma vez que a adaptação ao local de cultivo irá garantir uma maior produtividade.…”