Since 1996, the primary objective of the New Crop Pathology Program at the University of the Free State has been to conduct a systematic survey of diseases occurring in cactus-pear [Opuntia ficus-indica (L.) Miller] orchards throughout the country and to investigate possible relationships between disease-causing microorganisms and various insects, specifically Drosophila sp. Numerous fungal gen...

While stress is expected to increase developmental instability (DI), not all studies confirm this. This heterogeneity could in part be due to the use of subtle differences between the left and right side of bilateral symmetrical organisms to quantify DI, leading to large sampling error obscuring associations with DI. Traits that develop simultaneously more than twice (such as flower petals or b...

Background and Aims: In spite of a long tradition of fruit-tree growing in all provinces of Iran, information on pear (Pyrus communis) tree viruses is scant. In order to identify of the nature of the virus like symptoms and decline in pear trees, we carried out a survey for the occurrence of four important viruses. Materials and Methods: Leaf samples of pear showing virus like symptoms wer...