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Summary and Conclusion of Session onBreeding Biotic Stresses - Maize DiseasesChairman : C. De LeonRapporteur : R. LaugitanThe presentations related to description of maize diseases present in different countries give agood background of the situation of maize diseases in Asia. With that background, the discussionwas guided towards analysis of specific topics related to regional collaborative projects on specificdiseases including downy mildews (DMs), stalk rots (SRs), and banded leaf and sheath blight(BLSB).1. Downy mildews:a. The use of lower levels of metalaxil as a seed treatment could be one of the reasons for theincreased tolerance to the fungicide that has been observed. The savings involved inapplying lower levels of fungicide will result in a more expensive control of these diseasesb. The classification of DM species needs to be reviewed. New technologies will clear thequestions that have emerged recently on relationships between previously identified speciesof these fungi.c. The breeding for resistance to all DMs in maize was recommended.2. Stalk rots:Activities on breeding for stalk rot resistance carried out by Indian researchers was commended.Now that lines have been generated with acceptable levels of resistance, it would be convenient toinclude the bulks, and selected lines of the populations, in nurseries to be distributed to interestedprograms. Best performing lines across I cations can be utilized in the development of hybrids orsynthetics by collaborators or by the Maize Directorate, India.3. Banded leaf and sheath blight:a. It has been difficult to identify resistant germplasm. Experiences with disease nurseriesestablished in S. China and India, indicate that there are different reactions for resistancebetween these locations. This is probably due to differences in virulence in the isolatespresent at those locations. The collection of fungal isolates in countries in the region isrecommended to study the differences between these isolates, anastomosis groups, etc.b. The re-establishment of disease nurseries where the same maize entries are screened forresistance was recommended.