Formulation of microbial fertilizers and pesticides: a key for their effective use
Author: Eligio MAlusa, INHORT
The major factors affecting bioinocula efficacy in the field are related to the plant genome (species or variety), the soil (physical-chemical-biological conditions), the agronomical practices adopted by the farmers (soil management) and the products themselves (formulation). EXCALIBUR is addressing all these aspects in its field trials. With regards to the latter issue, at INHORT we are testing which are the formulations that are best suited for the different strains.
For example, bacteria of the genus Pseudomonas, which are difficult to be stored because they are not forming spores, have been formulated in alginate beds (Fig. 1). Alginate is a compound that derives from algae and can polymerize under certain conditions. We have tested several compounds to be used with alginate (e.g. starch) in order to improve its practical use in industrial production and verified the bacteria embedded in the beds also by electron scan microscopy (Fig. 2).
The production by fermentation on cereal grains was found to be well suited for some fungal strains selected for the trials. This method allows to have an easily applicable product in the field, which can also be “seen” by the farmers (Fig. 3), thus overcoming the suspicion about the real content of the product.
Fig. 1: Alginate beds containing different additives (please note the different colors of the beds) which are designed to ease the application of microbial-based products.
Fig. 2: Micrographs of an alginate bed showing its microscopic morphology and the bacteria cells embedded in it.
Fig. 3: A formulation of a fungal inoculum with cereal grains.