The effect of pre-harvest desiccation on the yield and physiological quality of landrace bean seeds

Abstract

An early harvest reduces the time that the seeds stay in the field under the effect of biotic and abiotic factors, which are responsible for their deterioration. So, the objective of this work was to determine the effect of pre-harvest desiccant application on the yield and physiological quality of common bean seeds. The experimental layout was completely random, the desiccant used was paraquat (400 g ha-1 a.i.), on a combination of three genotypes: 'BAF55', 'BAF84' and 'BAF112' (commercial black cv. IPR88- Uirapurú) with three plant desiccation periods (26, 30, 34 days after flowering (DAF)), and a control (plants not des iccated). Post-harvest, productivity was estimated and, soon after, germination tests were carried out with and without accelerated ageing; main root radical length and hypocotyls length were measured as well as electrical conductivity. The desiccation maintenance the cell membrane integrity in the 'BAF112' and 'BAF55' genotypes when the paraquat was sprayed at 26 DAF. The results showed that the two landrace beans genotypes outperformed the commercial one in terms of seed yield and that the seeds produced were of higher physiological quality in terms of membrane integrity. The landraces 'BAF55' and 'BAF84' showed yield higher than commercial ('BAF112'). The early of the harvest through desiccant sprayed on plants 26 DAF did not adversely affect the yield or physiological quality of harvest bean seeds.