Snap beans for organic farming and evaluation of resistance to the common bacterial blight

Abstract

Snap beans have been widely used in organic farming as a good income source and an alternative to diversify production, with increasing use in crop rotation. This work reports the evaluation of 25 bush-type snap beans accessions for their suitability to integrate a breeding program for organic farming, as well as for their resistance to the common bacterial blight (CBB). Agronomic performance was assessed in two field experiments (September-December, 2013; April-June, 2014), in complete blocks at random, while resistance to CBB was assessed in greenhouse, in a completely randomized trial. Plants were challenged with two isolates, one from Xanthomonas axonopodis pv. phaseoli and another from X. fuscans subsp. fuscans. Accessions UEL 402, UEL 405, UEL 407, UEL 408, UEL 412, UEL 417 and UEL 420 were highly productive in both seasons (averages of 10.3, 8.7, 9.5, 9.2, 8.9, 9.3 and 9.2 t/ha, respectively), and are promising for use both as cultivars by organic farmers in the region of Londrina and also as germplasm in breeding programs for developing cultivars adapted to the region. Although all accessions were moderately susceptible to CBB, accessions UEL 407, UEL 409, UEL 411, UEL 412, UEL 424 and UEL 431 presented the lowest values for the area under CBB progress curve for both isolates.

Bush Snap Bean Genotypes Under Conventional and Organic Cultivation

“…Brunner et al (2014) analyzed eight bush snap bean genotypes, in an organic system, in Puerto Rico and found that the cultivars Provider, Contender, Festina, and Jade were among the most productive, with a range from 10.90 to 14.60 t ha -1 . Andrade et al (2017) evaluated 25 bush snap bean accessions under organic cultivation in Londrina-PR; they found yields between 5.14 and 9.72 in the September-December season and between 7.02 and 11.07 t ha -1 in April-June.…”

“…One issue that permeates agricultural production debates is the focus on sustainability, emphasizing organic and agroecological production systems. In addition, the search for healthy food also increases the demand for food from these systems, requiring cultivars developed according to agroecological principles, using germplasm adapted to local conditions (Andrade et al, 2017).…”

Seed production of bush snap beans genotypes in conventional and organic systems

“…These have contributed to the expansion of snap beans crop in several regions of Brazil, with it standing out as a good low operational cost option for Fall/ Winter in irrigated areas, since they enable the mechanization of most cultivation operations. Moreover, these cultivars produce good quality pods, which in turn has led to the greater demand for this group by producers (Francelino et al, 2011;Andrade et al, 2017;Peixoto & Cardoso, 2016;Vaz et al, 2017).…”