The technology addresses the issue of two maize diseases: Grey Leaf Spot (GLS), and Maize Streak Virus (MSV) on upland maize. Research focussed on identifying and breeding for genetic resistance has been conducted in the southern highlands of Tanzania. Two hybrids have been released (UH615 and UH6303) with high levels of resistance to GLS. These are highly demanded by farmers as they produce a good cob, are high yielding and disease resistant. The project has worked to ensure that farmers can access the seed and this has led to collaborations with the private sector. Unfortunately a high level of resistance in Open Pollinated Varieties (OPVs) has not yet been validated.