|RAY, D - University Of Arizona|
Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/29/2010
Publication Date: 5/21/2010
Citation: Coffelt, T.A. and Ray, D.T. 2010. Cutting height effects on guayule latex, rubber and resin yields. Industrial Crops and Products. 31:264-268.
Interpretive Summary: The commercialization of guayule for hypoallergenic latex has renewed interest in production factors such as harvesting height and frequency. A four year study was conducted on five lines of variable plant height to determine the effects of harvesting at 50% of plant height compared to the recommended 100% at 2, 3, and 4 years of growth. Total yields of biomass, latex, rubber, and resin were determined for plants harvested annually and biannually after two years with a single harvest after three and four years. Harvesting at 100% of plant height gave higher yields than harvesting at 50% of plant height independent of harvest frequency. Harvesting at 100% after four years of growth gave the highest yields, but harvesting on a two year schedule may be better for harvesting equipment and extraction equipment. Optimum harvesting schemes at 100% of plant height may need to be developed for each line and environment. These results will benefit guayule growers, processors, and researchers.
Technical Abstract: Guayule (Parthenium argentatum Gray) is a perennial shrub native to the Chihuahuan Desert. While guayule traditionally has been cultivated for rubber, more recently it is being cultivated for its hypoallergenic latex. Other uses including termite resistant wood products and as an energy source have also been identified. Major advances have been made since 1970 in the development of improved guayule germplasm. However, the effects of harvesting practices such as cutting height and frequency on latex concentration and yield of newly developed germplasm have not been reported. These results are needed in order to develop production schemes for the successful commercialization of guayule. The objectives of this study were to determine the yield and concentration of latex, rubber, and resin of five guayule lines harvested at two cutting heights over three years and five harvesting schedules. Treatments were replicated four times. Harvesting at 100% of plant height gave higher yields than harvesting at 50% of plant height independent of the harvest schedule. Harvesting at 100% after four years of growth gave the highest yields, but more research is needed to determine if harvesting on a two year schedule may be better for harvesting equipment and extraction equipment. AZ-2 and AZ101 were the largest plants, while N9-3 and 11591 were smaller with AZ-1 intermediate. As indicated in previous studies, the environment plays a large role in determining biomass, latex, rubber, and resin yields in guayule. In the future, optimum harvesting schemes at 100% of plant height may need to be developed for each line and environment.