olive trees have greater resistance to disease and can endure harsh weather conditions than many other fruits of the Mediterranean region. it is true, however, that temperate climates, characterized by warm, dry summers and rainy winters, favor good harvests. According to ltalian folk tradition,there are five factors that create the ideal conditions for the world's biggest producers of olive oil. There are about thirty varieties of olives growing in ltaly today, and each yields an oil with its own unique characteristics.