During
World War II, Velasco conducted research on the
photoperiodism of the
rice plant. Among his findings, which were published only after the end of the war, was that the
Elon-elon variety flowered during short days when there was less than 12 hours of light. Velasco was also noted for his research on the physiology of the
coconut, a common crop in the Philippines. He studied the mineral nutrition of areas planted to coconut, the development and utilization of coconut products, and the nature and cause of
cadang-cadang, a disease that plagued the crop of small coconut farmers throughout the country. With respect to cadang-cadang, Velasco was skeptical of the still-prevalent view that the disease was viral in nature, and devoted considerable effort to prove his thesis that it was caused by an element in the soil that was toxic to the coconut plant. ==Citations==