Puerto Rico, whose economy depended heavily on its agriculture, felt the effects of some of the crop diseases.Scientists such as Agustín Stahl, Fermín Tangüis and Fernando López Tuero conducted investigations and experiments in the fields of agriculture, botany, ethnology and zoology.[4] The following is a list of some of Puerto Rico's notable scientists and inventors with short profiles that include the scientific contributions, inventions and achievements in their respective fields.Among the products that Puerto Rico exported were tobacco, cotton, ginger, pineapples and citrus fruits.[93] Hydroelectric Wave-Energy Conversion System Semiconductors The cuatro is the national instrument of Puerto Rico.