Research was conducted to determine percentage excretion and germination or viability of common crupina (Crupina vulgaris Cass. # CJNVU) achenes fed to sheep (Ovis aries), cattle (Bos taurus), deer (Odocoileus hemionus), horses (Equus cabullus), and Chinese pheasants (Phasianus colchicus). No achenes were found in the feces of sheep. Horses (nonruminant), deer, and cows (both ruminant animals) excreted 5, 3, and 25%, respectively, of the achenes consumed. The mean percentage achene excretion for pheasants was 23%; however, excretion was highly variable among individuals. All achenes excreted by any test species were detected within 5 days after consumption. The percentage germination or viability of excreted achenes ranged from 29% (cows) to 81% (deer). The percentage of consumed achenes that were excreted and viable ranged from 2 to 7% for large animals, whereas it was 17% for pheasants.

The influence of depth (0 to 20 cm) and duration (1 to 31 months) of burial on the deterioration, germination, and viability of common crupina (Crupina vulgaris Cass. ♯ CJNVU) was investigated in the field. Germination and decay of achenes prior to removal from the field were greater at 0- to 10- (7%) and 0- to 15- (21%) cm burial depths than at the 20-cm burial depth for 1980 and 1981 seedlots, respectively. After 25 months of burial, 41 and 26% of the achenes had not deteriorated for the 1980 and 1981 seedlots, respectively. Germination was greatest for nondeteriorated achenes recovered from 3- and 20-cm (63%) and least for the 10-cm burial depth (44%). Common crupina achenes recovered from the field over 25 months of burial exhibited a pronounced periodicity of germination, which was related to induced winter dormancy. The viability of achenes decreased linearly from 90 to near 0% over 31 months of burial.

A Geographic Information System (GIS) was developed to evaluate its utility in an eradication program of common crupina. Infested areas were recorded in the GIS along with information normally found on United States Geological Survey topographic maps. Infested areas were separated into management areas according to possible treatment method and special environmental or health requirements such as proximity to streams or inhabited buildings. The location, size, and type of each management area were recorded in the database. The database was constructed to maintain treatment and efficacy data for tracking the process of eradication for each infestation. Areas were identified for detection surveying, including coordinates for navigating with a global positioning system (GPS).

Achene germination of common crupina (Crupina vulgaris Cass. ♯ CJNVU) was 86% or greater at day/night temperatures ranging from 15/4 to 29/25 C. Germination was greatly reduced at a day temperature of 36 C, regardless of the night temperature. The time required for maximum germination (9 to 19 days) increased with decreasing night temperature. Maximum leaf area, rosette diameter, and dry-matter accumulation during vegetative growth occurred at 22/18 to 29/25 C, 22/18 C, and 22/18 C, respectively. The plants attained 50% or more of maximum dry-matter accumulation at day/night temperatures ranging from as low as 22/4 and 15/11 C to as high as 36/25 C. Net assimilation rate was relatively insensitive to growth temperature. Rosettes of common crupina grown at 22/11 or 29/18 C exhibited almost complete photosynthetic and respiratory temperature acclimation. Increasing the photoperiod from 10 to 12, 14, or 16 h accelerated flowering. Maximum achene production occurred in the 16-h photoperiod, but viable achenes were produced in all photoperiods. Temperature during vegetative growth influenced subsequent responses to photoperiod. Plants grown for 83 days in a 14-h photoperiod at 15/4 or 22/11 C and transferred to 26/20 C flowered and produced seed in photoperiods of 8 or 16 h. Plants grown at 29/18 or 36/25 C subsequently flowered only in the 16-h photoperiod at 26/20 C. Common crupina has a wide tolerance of variations in temperature and photoperiod. Its range in the United States can be expected to continue to increase.

An eradication plan is needed to counteract the increasing number of invasions by new plant species and the cost of resulting control programs. An eradication plan includes early detection of new species, assessment of the invader's noxious potential, surveys, understanding of the invader's biology, and technology incorporated into a strategy to eliminate the species and to revegetate invasion sites. Early detection increases the probability of successfully eradicating invading plants. Key factors in determining a plant's noxious potential are similarities among the climates of the invaded area and endemic population, the plant's history of spread, and its ability to germinate. Surveys are necessary to detect new species and to assess their threat. Reliable surveys depend on using proper methods and tactics. Population dynamics indicate the stage of a plant's life cycle most vulnerable to eradication treatments, the time to deplete viable propagules from the soil, and the strategy to stop spread. Eradication technology is based on a plant's population dynamics and must eliminate every plant from an infestation. The survey data, population dynamics, and eradication technology are combined into an eradication strategy that must stop spread, prevent reproduction, and deplete viable propagules from the soil. An effective eradication strategy specifies where and when to apply treatments, quarantine measures, criteria to assess progress, steps to prevent further invasions, and cost appraisals.

The compatibility of rhodamine B dye {N-[9-(2-carboxyphenyl)-6-(diethylamino)-3H-xanthen-3-ylidene]-N-ethyl ethanaminium chloride} with picloram (4-amino-3,5,6-trichloro-2-pyridinecarboxylic acid) or dicamba (3,6-dichloro-2-methoxybenzoic acid) was evaluated in the laboratory and field. Rhodamine B dye formulation (with or without a surfactant) did not affect dry weight of residue precipitated when mixed with dicamba. Formulated dye precipitated 11% more residue than nonformulated dye when mixed with picloram. Common crupina (Crupina vulgaris Cass. # CJNVU) field plant density was higher after applying a picloram spray solution with nonformulated rhodamine B dye compared to picloram alone. Common crupina density and biomass were higher after application with nonformulated dye and dicamba compared to dicamba alone.

Seedling emergence and seed bank longevity were followed in field experiments with natural populations of common crupina for 4 yr. Emergence the first fall after dissemination was 90 to 98% of all seedlings eventually to emerge from the seedbank. Seedling emergence over time did not differ between plots which either were treated with the potassium salt of picloram or were hand weeded. No viable seed remained in the soil 25 to 26 months after seed production stopped. Five locations in a common crupina infestation undergoing eradication were sampled for seed in the soil. No viable seeds were found during the first year of the eradication, and no intact seeds were found after 4 yr.