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ARS Home » Pacific West Area » Maricopa, Arizona » U.S. Arid Land Agricultural Research Center » Plant Physiology and Genetics Research » Research » Publications at this Location » Publication #206373
Title: POST-HARVEST STORAGE EFFECTS ON GUAYULE LATEX, RUBBER, AND RESIN CONTENTS AND YIELDS

Author
item Coffelt, Terry
item NAKAYAMA, F - USALARC, COLLABORATOR
item RAY, D - UNIV OF AZ, TUCSON
item CORNISH, K - YULEX CORP, AZ
item McMahan, Colleen

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/20/2008
Publication Date: 3/1/2009
Citation: Coffelt, T.A., Nakayama, F.S., Ray, D.T., Cornish, K., McMahan, C.M. 2009. Post-harvest storage effects on guayule latex and rubber yields. Industrial Crops and Products. 29(2-3):326-335.

Interpretive Summary: Guayule is a new crop being commercialized for hypoallergenic latex production. Since natural processes that occur in the plant following harvest result in loss of latex almost immediately and immediate processing of guayule shrub for latex on a commercial scale is not feasible, a storage system that maintains latex concentration and yield is needed. Results from this study showed that keeping harvested shrub moist prior to latex extraction maintained latex yields and concentration compared to dry storage, but in some cases increased extractable latex yields by over 100%. Storing the shrub under moist conditions will allow growers and processors more flexible harvesting and processing schedules, since the shrub can be harvested and stored until processing equipment is available.

Technical Abstract: Guayule is a new crop being commercialized for hypoallergenic latex production. Since natural processes that occur in the plant following harvest result in loss of latex almost immediately and immediate processing of guayule shrub for latex on a commercial scale is not feasible, a storage system that maintains latex concentration and yield is needed. The objective of this study was to determine the effects of different storage conditions on the latex yield and concentration on harvested guayule shrub. The experiment was established by transplanting plants in the field at the University of Arizona Maricopa Agricultural Center, Maricopa, Arizona, USA, on 22 March 2001. A randomized complete block design with four replications was used. Two lines (11591 and AZ 2) were used for this experiment. Twenty plants of each line were harvested six times (November 2002, March 2003, July 2003, November 2003, March 2004, and July 2004) from each field plot and two plants of each line randomly assigned to each of ten storage treatments prior to chipping for latex extraction. AZ-2 had significantly lower latex and rubber concentrations and higher biomass than 11591. Latex and rubber yields were not significantly different between the two lines. The treatment results from this study show that keeping harvested shrub moist prior to chipping should allow industry to not only maintain latex yields similar to fresh harvested shrub, but in some cases significantly increase the latex yields during the latex extraction procedure. Storing the shrub under moist conditions will also allow more flexible harvesting and processing schedules, since the shrub can be harvested and stored until processing equipment is available.