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ARS Home » Pacific West Area » Logan, Utah » Poisonous Plant Research » Research » Publications at this Location » Publication #192303

Title: EFFECT OF SHADE ON ALKALOID CONTENT OF LUPINUS LEUCOPHYLLUS

Author
item GAY, CLIVE - WSU
item Panter, Kip
item MOTTERAM, ERNIE - WSU
item GAY, JOHN - WSU
item Wierenga, Terrie
item PLATT, TOM - WSU

Submitted to: Poisonous Plant Global Research and Solutions
Publication Type: Book / Chapter
Publication Acceptance Date: 5/31/2006
Publication Date: 6/20/2007
Citation: Gay, C.C., Panter, K.E., Motteram, E.S., Gay, J.M., Wierenga, T.L., Platt, T. 2007. Effect of shade on alkaloid content of lupinus leucophyllus. Poisonous Plants Global Research and Solutions, Chpt. 69, pp. 411-413

Interpretive Summary: Lupine-induced arthrogryposis (crooked calf disorder) is a significant problem for ranches on the semi-arid Cow Creek drainage of the channeled scablands of east-central Washington State. The dominant lupine on affected ranches in Adams County is Lupinus leucophyllus. The incidence and severity of crooked calf is low in years where there is low rainfall and outbreaks of severe disease on individual or multiple ranches occur during wet periods. Whereas it is possible that rainfall and soil moisture affect the alkaloid content and/or palatability of L. leucophyllus, it is also possible that shade from clouds passing to higher rainfall areas east of Adams County or shade from the superior growth of other pasture species in wet years could influence alkaloid concentrations. Differences in alkaloid concentrations between the shaded and unshaded parts of the plants were examined by two-sample t-tests. This pilot study showed a difference in the concentration of some alkaloids. Given the small sample size, the results suggest further studies on the effects of shade on alkaloid concentration and plant palatability are warranted.

Technical Abstract: Lupine-induced "crooked calf" syndrom is a significant problem for ranches in the semi-arid region of the channeled scablands of eastern Washington State. Rainfall and soil moisture has been proposed to affect the alkaloid content and/or palatability of L. leucophyllus. It is also possible that shade from clouds passing to higher rainfall areas east of Adams County or shade from the superior growth of other pasture species in wet years could influence alkaloid concentrations. To test this hypothesis the north-facing half of each of 5 plants of L. leucophyllus was shaded by constructing a tent with black 4mm plastic that stretched from the center of the plant clump over to its north edge so as to prevent direct sunlight but allow indirect light to the north-facing half. The shading was left in place for 7 days following which the shaded and the unshaded halves were harvested for analysis of alkaloid content and concentration. Differences in alkaloid concentrations between the shaded and unshaded parts of the plants were examined by two-sample t-tests. This pilot study showed a difference in the concentration of some alkaloids but given the small sample size, these results suggest further studies on the effects of shade on alkaloid concentration and plant palatability are warranted.