|Nelson, John - UNIV OF AZ MAC MARICOPA|
|Watson, John - UNIV OF AZ TUCSON AZ|
Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 15, 1998
Publication Date: N/A
Interpretive Summary: Improvements of suitable cultural practices for Lesquerella fendleri are necessary for this potential industrial crop to be successfully grown in cultivation. Low seed and seed-oil yields result when insufficient nitrogen amounts are available to plants during the growing season. Applying rates of nitrogen ranging from 30 to 180 kg per hectare increased seed and oil yields and plant dry weight matter. Seed oil was decreased at some of the higher rates, but oil quality was unaffected. An application of 120 kg of nitrogen per hectare was optimum. This amount can be given in either one application or split applications during the growing season. This information could help move lesquerella into commercialization and increase profits for farmers who grow it.
Technical Abstract: Progress has been made towards the commercialization of Lesquerella fendleri (Gray) Wats. as a fall-planted oilseed crop for the southwestern United States. Research to develop suitable cultural practices for commercial production of lesquerella has been underway since the later 1980s; however, information is limited on the plant's nitrogen (N) requirement. Field experiments were conducted during two growing seasons to determine the optimum amount and timing of N applications for lesquerella production. Yield results indicate that lesquerella grown on desert soils is strongly influenced by N fertilization. Nitrogen rates as high as 180 kg N per hectare increased seed yield. Seed oil content decreased as the N rate was increased. The increase in seed yield at the higher N rates generally offsets the decrease in oil content, but oil yields appeared to be near maximum at 180 kg N per hectare. Split-applications of N in the spring increased seed and oil yields in one of two seasons. Nitrogen had no influence on 1000-seed weight or lesquerolic acid content of the oil. No spring leaf blade total N level was identified as being related to maximum seed yield. A suggested N management program for lesquerella production is to apply a small portion of N at planting time and the major portion of N in several applications during the period from onset of bloom through full bloom (February-April).