Response of white yam (Dioscorea rotundata Poir.) to Bacillus licheniformis inoculation and shading

Abstract

The white yam crops make a substantial contribution to sustaining the food security of millions of people worldwide. However, obtaining good quality planting material is a major challenge. Multiplication rates are low, with expensive seeds and prone to contamination by pests and pathogens in traditional production systems. In addition, the intensive use of natural resources has caused impacts on biodiversity, quality of natural resources and global warming, which forces farmers to mitigate and adapt to these conditions. In this sense, the present study evaluated the response of apical cuttings of white yam to different levels of shading (0 %, 65 % and 80 %) and to the inoculation of the rhizobacterium Bacillus licheniformis-DSC1 at doses of 2 and 6 mL. A randomized complete block design with factorial arrangement and three replications was used to set up the experiment. The results demonstrated the capacity of the rhizobacterium B. licheniformis-DSC1 to increase the survival of the cuttings by 42 % with respect to the non-inoculated cuttings. It was also shown that the combined use of 65 % shade and a dose of 2 mL of rhizobacteria increased the percentage of tuberization of the cuttings by 33.33 %. The use of cuttings and microbial inoculants for seed tubers is a promising and sustainable strategy to be implemented on a large scale.