Grafting green beans for improved yield and fruit quality

I. Mourão, L. Moura, L.M. Brito, J. Coutinho, S.R. Costa
Grafting of green beans (Phaseolus vulgaris L.) to prevent biotic and abiotic stresses, is a safe and easy to manage technique for protected crops suitable for organic production, that has scope to be improved. With this aim, we evaluated the grafting effects on yield and pod quality of two commercial cultivars, ‘Oriente’ and the standard Portuguese traditional cultivar ‘Vagem rajada’. Field trials were carried out in the same season in two different sites (Ponte de Lima – PL, and Póvoa de Varzim – PV) in the NW Portugal, with the Phaseolus coccineus L. rootstocks cultivars Aintree (P1) and White Emergo (P2) (both from Tozer Seeds) and ‘7 years bean’ landrace ‘Ponte de Lima’ (P3). Self-grafted and non-grafted plants were also included as controls. In site PL, with low soil fertility and 3.3 stems m‑2, the crop showed symptoms of Fusarium oxysporum f. sp. phaseoli (Fop) and the highest yield was achieved with the cultivar ‘Oriente’ grafted onto P3, followed by the scion/rootstock combinations cultivar ‘Oriente’/P2 and cultivar ‘Vagem rajada’/P2 and P3. In site PV, with increased mineral nutrient availability, lower crop density (2.1 stems m‑2) and with no disease symptoms, similar yields were found for all crop treatments, except for both cultivars grafted onto rootstock P2, which showed lower yields, compared to the non-grafted plants. Grafting with P2 and P3 rootstocks increased P content of the pods for both cultivars in both experimental sites, and increased Mg and Ca contents in site PL and PV, respectively, compared to self-grafted and non-grafted plants. In addition, both cultivars grafted onto rootstocks P3 in site PL, showed a 15% increase in the mean length per pod, compared to control plants. Therefore, further research with P3 rootstocks to produce healthy grafted seedlings may be a key point for wider use of grafted green beans.
Mourão, I., Moura, L., Brito, L.M., Coutinho, J. and Costa, S.R. (2020). Grafting green beans for improved yield and fruit quality. Acta Hortic. 1286, 141-148
DOI: 10.17660/ActaHortic.2020.1286.20
Fusarium oxysporum, Phaseolus coccineus, Phaseolus vulgaris, pod nutrient content

Acta Horticulturae