Plant diseases and insect pests are major limiting factors that reduce crop production worldwide. The interference and damage fail plants from reaching their genetic potential. Insects are responsible for two significant kinds of damage to growing crops. In addition, in their efforts to manage or control pests and diseases, humans spend a great deal of time and money developing and applying new pesticides. Inappropriate application of these pesticides may have damaging environmental and human health impacts. The first is direct injury to plants caused by insects eating leaves, burrowing holes in stems, fruit, and roots, inhabiting and parasitizing vascular tissues, and disrupting water and nutrient uptake. The second is indirect damage, where the insects do little or no harm but transmit bacterial, viral, or fungal infection to a crop.

Plant geographic origin significantly influenced relative concentrations of nutrient content and morphology with variations between origins of the same species (i.e., genetic factors). Altitudinal gradients differ in several factors, including atmospheric pressure, precipitation, solar radiation, and soil nutrients. Because low temperatures at high altitudes are likely to limit decomposition and other soil processes, soil organic carbon (C) concentration may increase. In contrast, the availability of soil nutrients (e.g., N and P) may decrease with increasing elevation. Moreover, climatic factors, indicated by air temperature, precipitation, and UV radiation, can also vary with altitudes, thus creating complex environmental changes along the altitudinal gradients-microbial communities.