Seed-applied bioprotectants for control of seedborne Pyrenophora tritici-repentis and agronomic enhancement of wheat

Seed-applied bioprotectants may be a useful for enhancing wheat health and specifically for managing seedborne inoculum of Pyrenophora tritici-repenti s, causal fungus of tan spot. Paenibacillus macerans and Pseudomonas putida reduced radial growth of the pathogen in culture, eradicated it from infec ted seeds, and reduced its transmission to seedlings from 16% (nontreated) to 0%, equivalent to the activity of iprodione & thiram. Trichoderma strain s, however did not have any effect on these parameters. In field plots, the bioprotectants Paenibacillus macerans (Embrapa Trigo), Pseudomonas putida (Embrapa Trigo), Trichoderma harzianum (BioWorks T-22), and Trichoderma vir ens (BioWorks G-41) each increased significantly (over nontreated) the seed ling emergence and grain yield of wheat; the agronomic enhancement was equi valent or superior to that of seed treatment with iprodione & thiram. Paeni bacillus macerans and Pseudomonas putida should find application in the int egrated management of tan spot and other diseases of wheat.