Elevating concentrations of capsaicin and dihydrocapsaicin in hot peppers using recycled waste

Five Capsicum accessions (PI 435916 and PI 438614 from Capsicum chinense; PI 370004 and Grif 9354 from C. baccatum and PI 438649 from C. annuum) were selected from the U.S. Department of Agriculture-Agricultural Research Service Capsicum germplasm collection to study the impact of four soil management practices: yard waste (YW), sewage sludge (SS), chicken manure (CM) and no-mulch (NM) bare soil on fruit concentrations of capsaicin and dihydrocapsaicin, yield, plant size and mature fruit characteristics (fruit weight, length, width, and wall-thickness) of plants grown under these practices. Regardless of soil treatments, PI 438614 and PI 435916 contained the greatest concentrations of total capsaicinoids (capsaicin and dihydrocapsaicin). Fruits of plants grown in soil mixed with SS contained the greatest concentrations of total capsaicinoids. Fruits of plants grown in SS or CM contained the greatest fruit weight. PI 438649 produced the greatest fruit weight, length and wall-thickness. The total marketable yield expressed as weight of fruit plants was significantly higher in soils mixed with SS and CM compared to those mixed with YW and NM soils.