Recent own Institute's research on plant protection agents (derivatives of salicylaldehyde and salicylic acid) was reviewed. Several disalicylalkenes were converted to agents of high antibacterial activity against plant and humane pathogens. Syntheses directed at prepg. new acetolactate synthase inhibitors resulted in a series of hydrazones and their transition metal complexes. Some chelates showed moderate fingicidal potency and very good activity against bacterioses of economically important plants.