Pear trees are susceptible to several diseases caused by fungi, viruses and bacteria. The National Gardening Association reports that fire blight is the most devastating to both commercial and home pear trees in the Unit... More » Health Conditions & Diseases

Pear trees need annual pruning and proper fertilization to provide a crop of healthy fruit. The trees also need to be trained into a growth pattern that promotes healthy branch development. You need fertilizer and prunin... More » Home & Garden Gardening & Landscapes Trees & Bushes

Deciduous fruit trees, such as pear trees, should be pruned in midwinter. Pruning during the dormant season gives the wounds a chance to heal over. Pruning done during the growing season can expose the trees to fire blig... More » Home & Garden Gardening & Landscapes Trees & Bushes

Infectious diseases are infections transmitted by organisms such as viruses, bacteria, parasites or fungi. These organisms live on or in the human body, where some have beneficial roles, while others cause diseases, acco... More »

According to WebMD, fever is a possible symptom of acute sinusitis, which is a blockage of the sinuses caused by fluids and infectious agents, such as bacteria, viruses or fungi. Sinus blockage is usually caused by condi... More » Health Conditions & Diseases

Potato diseases include infestations of the root, leaves and tubers caused by bacteria, fungi and other viruses. Common potato diseases include potato wart, soft rot and potato blight, according to the American Phytopath... More » Home & Garden Gardening & Landscapes Outdoor Plants & Flowers

Interstitial pneumonia is a type of lung disease caused by fungi, bacteria or viruses infecting the lung's interstitial, according to WebMD. Other possible causes of this disease include autoimmune diseases, radiation tr... More » Health Pain & Symptoms