Answer:
1. Hills have sloped terrain that ensures that every tree gets abundant sunlight, which increases both yield and quality of fruits produced. Trees in flat land can be overshadowed by neighbouring trees that compete for sunlight.
2. Hills, due to their sloped terrain, facilitates drainage of rainwater, thus keeping the feet of trees free of excess moisture. Most fruit trees prefer well drained terrains for their growth.
3. Hills and mountains (especially the windward side), receive higher precipitation than the plains, on account of orographic rainfall. Higher and more distributed rainfall is favourable for fruit trees, and this reduces the requirement of irrigation.
4. Hills and mountains, on account of their higher altitude, are usually cooler compared to the plains (this applies mainly for fruit growing regions in the tropical and subtropical latitudes). Such cool climates may be suitable for fruits such as subtropical and temperate fruits such as berries, plums etc.
5. The soil in most hilly and mountaineous regions are acidic in nature, and therefore ideal for fruit cultivation and horticulture. These soils are usually fresh and rich in humus (organic material), since they would hardly have been put to agricultural use previously.
