Microbial seed coating as a tool to enhance crop growth and stress tolerance
With continuous degradation of microbial life in arable soils due to several factors such as excessive pesticide application, drought, and pollution of irrigation water, inoculation with beneficial microbes becomes an essential part of good horticultural practice. There are numerous groups of beneficial soil microbes that can be reintroduced into degraded soil where the native microbial populations were diminished or eliminated. Although these microbes can provide significant benefits to early plant growth, contribute to stress tolerance and even enhance the yield of the inoculated crop, the application is often not feasible due to high cost and extra labour involved in microbe introduction. By contrast to inoculum broadcasting or spraying in the field, seed coating seems to be a feasible mode of microbe introduction in particular for broad-scale agriculture and horticulture. The demands of microbial inocula for seed treatment are much lower and, therefore, cost/benefit balance is in favour to extensive implementation of microbial inoculation. Here we present experimental results showing that seed coating is an efficient strategy to introduce microbial inoculants into the cultivation practice. Although the technique has been mainly tested on cereals and some legumes, there is high potential to use the same approach for vegetables and other horticultural crops. In our studies seed coating has been performed with arbuscular mycorrhizal fungi (AMF) inocula, with Trichoderma harzianum or Pseudomonas putida. Five experiments with chickpea, pea, maize and wheat performed in pots or field showed that the seed coating has a potential to introduce beneficial microbes into the roots or rhizosphere of the plants and, therefore, increase early crop growth and stress resistance. Possible ways of large-scale implementation of coating techniques should be further exploited and drawbacks of the technology addressed and solved to ensure its wider use in horticulture.
Vosátka, M., Rocha, I., Ma, Y., Švecová, E.B. and Oliveira, R. (2020). Microbial seed coating as a tool to enhance crop growth and stress tolerance. Acta Hortic. 1273, 401-408
microbial preparations, mycorrhizal fungi, plant growth promoting rhizobacteria, legumes, wheat, maize, pea, chickpea