Question

In the lower regions of Uttaranchal, a toxic weed called leafy spurge was accidentally

Answer 1

Leafy spurge (Euphorbia esula) is a noxious, perennial weed that infests pastures, range land and waste areas in the northern Great Plains. The objective of this study was to determine the productive potential of this species when grown under optimum agronomic conditions. Plants were fertilized and irrigated. Oil, hydrocarbon, total protein, and dry-weight production were measured on 3 harvest dates. Calorimetric analyses were performed to determine the potential of leafy spurge as a fuel crop. The hydrocarbon content of 12 strains of leafy spurge was determined to measure genetic variability for this trait. The addition of fertilizer doubled dry-weight productionmore » but did not affect percent oil or hydrocarbon content. Oil and hydrocarbon production averaged 6.8 and 0.6% on a plant dry-weight basis. Maximum production of plant biomass, protein, and hydrocarbon was obtained from a mid-July harvest. Oil content increased later in the growing season. The total protein content of leafy spurge averaged 12%. Whole-plant biomass had a caloric value of 4407 cal/g while the oils contained 10,019 cal/g. Leafy spurge hay can produce 4 times more energy per year than wheat straw; therefore, the immediate potential of leafy spurge whole-plant biomass as a locally grown fuel crop for home-heating purposes is suggested.« less

Release of picloram from leafy spurge (Euphorbiaesula L. ) roots

SciTech Connect

Hickman, M.V.

1988-01-01

Picloram (4-amino-3,5,6-trichloro-2-pyridinecarboxylic acid) exudation from leafy spurge (Euphorbia esula L.) roots following foliar application was determined with field trials examining the effects of plant growth stage, picloram rate, and time interval after treatment and with laboratory studies examining the effects of picloram rate, picloram plus 2,4-D, and root temperature. Release of /sup 14/C from leafy spurgeroots in the laboratory was not affected by picloram rates from <0.005 to 0.28 kg/ha or by combining picloram at 0.14 kg/ha plus 2,4-D up to 1.12 kg/ha. No consistent effect was detected for increasing root temperatures from 14 to 32 C. The temperaturemore » coefficient (Q/sub 10/) for picloram release was 1.3 +/- 0.8. Most /sup 14/C exudates from leafy spurge roots co-chromatographed with /sup 14/C-picloram suggesting that picloram is exuded as the parent acid or a rapidly hydrolyzed metabolite. Most picloram release occurred from the upper 5 cm of the root system. /sup 14/C distribution in leafy spurge suggests symplastic movement. Only about 28% of the applied picloram was absorbed, 75% remained in the leaves and stems of the plants. Over 60% of the /sup 14/C that entered the plant roots was released to the nutrient solution.« less