Why are the leaves of my Nashi Pear Tree turning brown then drop off?

Hi Margaret,

Sounds like pear scab, a bad fungal disease (see link) http://www.dpi.nsw.gov.au/agriculture/horticulture/pomes/health/apple-and-pear-scab Spray with either Yates Leaf Curl Copper Fungicide Spray at green tip stage in late aug - early sept then again with mancozeb at spurburst and repeat mancozeb every 10 days through October. Every 14 days through november. every 3 weeks Dec to Feb until 3 weeks before harvest. Ideally alternate mancozeb with another fungicide as listed in article (see link)