Back A. M. Primavesi
Fazeda Ecologica, Itai, SP, Brazil
Full Paper (PDF File: 97KB)
Abstract
A study was conducted to determine whether seed treatment of rice and maize
with Effective Microorganisms (EM) and micro nutrients could reduce the
incidence of disease and parasite injury, and prevent nutrient imbalances
after germination. Potassium and certain micro nutrient metals (e.g., copper,
zinc and manganese) are essential activators of enzyme systems for the
biosynthesis of organic compounds in plants. Foliar analysis of rice plants
affected with blast (caused by the fungal pathogen Piricularia oryzae Cav.)
showed low Cu and Mn levels proportional to nutrient ratios involving nitrogen
(N:Cu), phosphorus (P:Mn), and iron (Fe:Mn). When Cu and Mn were applied
to soil results were inconclusive. However, when seeds were treated directly
with Cu and Mn, results were highly significant and no blast occurred.
All treatments were applied with and without EM. The EM treatments increased
rice yields significantly, and decreased the level of blast infestation
but did not prevent it.
Maize plants without prior seed treatment were found to have a low Zn content and 20 percent of the seedlings were infested and destroyed by the stem borer Elasmopalpus lignosellus. Seeds treated with zinc sulfate (ZnSO4) produced healthy seedlings and were not attacked by this pathogen. Another insect pest of maize is Spodoptera frugiperda the larvae of which destroys the tassel and main shoot of plants. Seed and soil treatment with boric acid (H3BO3) prevented infestation and injury by this pathogen.
When EM was applied to maize plants without Fosmag (a fertilizer containing P, Ca, Mg, S and Zn) there was no increase in yield. However, when EM was applied with Fosmag, maize yield increased significantly, especially when applied with Skrill (a micro nutrient fertilizer mixture). Results indicate that EM has its greatest effect in highly fertile soils that receive regular applications of organic amendments, and less so in marginal soils.