It is possible that this nonnative species may eventually become a problematic weed in these more-open wetland areas.The challenge in controlling stinkwort is applying the appropriate management at the proper time. Although traditional methods of control, including mechanical and chemical techniques, can be effective, determining the most appropriate timing has been difficult. If management actions are not taken before plants begin to produce seeds in the fall, there is a risk that they will help disperse seeds rather than control stinkwort populations. For example, mowing may move seeds on equipment for long distances when conducted too late in the season. Unfortunately, a poor understanding of the biology of this plant and of how to control it effectively have led to unsuccessful management of growing infestations as well as much wasted time and money. However, management tools that prevent seed production for 1 to 2 years have the potential to greatly reduce the soil seedbank and, thus, the population size.There are currently two biological or cultural practices that can be employed to limit the ability of stinkwort to invade an area. One is to minimize disturbances such as overgrazing and soil manipulation in natural and rangeland sites. Second, harvest drying rack pastures should be managed for dense, competitive stands of desirable perennial or annual grasses that maximize ground cover in spring, when stinkwort seedlings are beginning to establish.
Mechanical practices. Mechanical control options can take advantage of the stinkwort root system, which is slow growing and initially relatively shallow. Plants may be controlled by hoeing or pulling. However, because stinkwort can cause dermatitis, it is important to wear appropriate protective clothing to minimize exposure to the irritating oils. Once in flower, stinkwort plants should be bagged and removed from the site to prevent seeds from maturing and dispersing after the plants have been cut and left on the soil surface. Mowing can provide partial control when conducted late in the season . However, buds remaining on branches below the level of the mower may regrow. Mowing a second time can give improved control, especially when conducted after the soil has dried out in mid- to late summer. In contrast, mowing too early, as is done on highways to reduce the threat of grass fires, will favor stinkwort by removing competing annuals while this weed is still small and lower than the mowing blades. Postemergence herbicides. Thus, in contrast to preemergence herbicides that are generally applied to larger areas before seeds germinate, post emergence applications can directly target known infestations visible to the applicator. However, the sticky oils on the foliage, especially on mature plants, make it difficult to control stinkwort with post emergence herbicides. To overcome this, it may be necessary to use ester formulations of post emergence phenoxy-type herbicides .
However, these compounds are more volatile compared to salt formulations , and some should not be applied when ambient temperatures will reach or exceed 80°F. In experiments we conducted for the post emergence control of stinkwort, we found that the salt formulation of triclopyr at 24-ounce acid equivalent per acre gave the most effective level of control following a post emergence application . Triclopyr is selective and relatively safe on grasses, but it must be used cautiously around vineyards, as grapevines are extremely sensitive to triclopyr drift. It is also important to note that control with post emergence herbicides is most effective when plants are young, actively growing and not exposed to stresses such as drought. For stinkwort, this is generally just before or at the time of bolting.Glyphosate at 1 quart product per acre also gave fairly good control, and anecdotal information from other land managers indicates that a rate of 2 quarts product per acre gives control similar to triclopyr at 2 quarts product per acre. Unfortunately, other herbicides, including aminopyralid and aminocyclopyrachlor , did not provide effective late-season postemergence control of stinkwort. As previously discussed, plants also partially recovered from late-season mowing. Pre- and early post emergence herbicides. Because stinkwort germinates throughout the rainy season, the most effective control options are likely to be broadleaf selective herbicides with both pre- and early post emergence activity, which can control both new germinants and young emerged seedlings. A fairly new group of foliar- and soil-active growth regulator herbicides have proven very effective in winter and spring applications for control of yellow starthistle and other members of the sunflower family . These herbicides have the ability to control both emerged young plants through foliar activity, as well as germinating seedlings through soil activity.
These chemicals include clopyralid , aminopyralid and aminocyclopyrachlor, and they are generally safe on grasses. In preliminary demonstrations, we found that winter applications of aminocyclopyrachlor and spring applications of Milestone VM+ showed the greatest potential for controlling stinkwort. Early-season application of glyphosate, however, controlled competing vegetation and so allowed late-germinating stinkwort to thrive. Thus, glyphosate is best used later in the season as a post emergence application. This ongoing research is building our understanding of the life cycle and basic biology of stinkwort, allowing us to make predictions of invasion potential that will help prioritize management activities. This work also lays a foundation for future investigation of specific management methods. If we expect to stop or slow the spread of this newly invasive plant in California, we must quickly develop effective management tools and an informed management approach.Communities and countries experiencing poverty, high unemployment, and economic reliance on tobacco growing are vulnerable to predatory tobacco industry behaviour. This analysis presents a cross-national survey of social disruption in tobacco farming to illustrate the association between tobacco companies and tobacco-related child labor, poverty and environmental destruction. The health risks of tobacco farming are beyond the scope of the study. Data on social disruption in tobacco farming was obtained through newspaper stories, published and unpublished reports, scholarly literature, documentary films, and tobacco industry publications such as annual reports and websites. The analysis shows that in all World Health Organization regions tobacco farming involves child labor and deforestation as well as tobacco industry behaviour promoting disruption in social and environmental life in tobacco farming communities. Tobacco companies generate huge externalities forcing farmers and consumers to pay the costs and concealing the actual cost of tobacco leaf and other tobacco products. Tobacco growing has detrimental effects on poverty and development. Developing countries that experienced an expansion of tobacco growing in the 1970s witness economically active people turning to tobacco growing and land transformed into tobacco farms, diverting valuable human and environmental resources. Tobacco jobs characterized by unfair contract arrangements, bonded labor, and child labor push vulnerable, primarily rural, populations deeper into economic disenfranchisement. Tobacco-related deforestation and pesticide poisoning contribute to the cycle of poverty and health insecurity of tobacco farmers. Poverty related to tobacco growing is compounded by rates of smoking of tobacco farmers that are higher than people who are not tobacco farmers, putting added pressure on weak health care systems in tobacco growing developing countries from the eventual appearance of tobacco-related death and disease. Tobacco farming is labor intensive. Each harvest requires 200 days of work per person per year, nine times as much work as in the production of beans, for example.
One tobacco farmer may tend up to 400,000 individual leaves in a nine month growing season. Since casual agricultural workers are nearly impossible to find, farmers are forced to use their families to help them cultivate and perform other physically demanding tasks in the fields. Tobacco farmers have little or not time and land to grow food or non-tobacco cash crops. Ogaya Bade, a tobacco farmer for more than 10 years in Kenya, vertical growing racks explained the difficulties of tobacco growing and its impact on food crops, when he said, “To get something out of this crop one has to dedicate all his time for the proper management of the crop, otherwise you will get nothing,” and experience perpetual famine, and have no time to produce food crops. In Kenya, 80% actually lose money from growing tobacco. In Malawi, where tobacco accounts for 70% of the country’s foreign earnings, people eat fried mice, corn husks, and poisonous plant roots to survive during frequent maize shortages while tobacco exports remain uninterrupted. Tobacco farmers sell their crop at auction or on a contract basis. A tobacco auction is a marketplace where buyers bid for the tobacco in open competition, in Malawi and Zimbabwe, for example. Under contract farming a tobacco farmer agrees to grow tobacco for a buyer who, in turn, provides seeds, pesticides and other inputs on loan, deducting the costs from earnings. Cigarette manufacturers such as British American Tobacco and leaf companies such as U.S.-based Universal Corporation and Alliance One International buy tobacco directly from farmers. Two emergent patterns exist in the global tobacco farming sector: the auction system is being replaced by the contract system; and global leaf companies operate farms and contract with farmers on companies’ farms in India and Brazil, for example. Tobacco leaf selling arrangements contribute to the poverty of tobacco farmers. Tobacco farmers require unpaid labor from wives and children to meet contract requirements. Global tobacco companies through direct contract arrangements with Mexican farmers make harsh demands on farmers while contractually exonerating themselves from responsibilities for tobacco farm working and living conditions. In Nigeria, BAT requires farmers to increasingly cover production and transportation costs, leaving farmers few choices such as a strike to express their grievances. Contract farming is linked with poverty in Uganda. Uganda is a world supplier of tobacco. Tobacco accounts for 3 percent of the country’s export earnings . In Uganda over 600,000 people out of a population of 25 million derive their livelihood from tobacco.23 22,000 tobacco farmers are contracted to supply tobacco directly to BAT in exchange for loans for inputs like seeds, fertilizer, and other supplies. The case of Angiepabo, a 24 year old tobacco farmer in Uganda shows the links between poverty and contract farming in Uganda. Angiepabo “sold 200 kilos of his crop to BAT. After paying the union dues and deduction of the BAT loans and offsetting the cost of the wood fuel he was left with approximately $1.00 to carry home. Maybe my daughter or son will one day win a BAT scholarship is the answer Angiepabo gives as to why he keeps growing tobacco” . In Kenya, BAT operates contracts with tobacco farmers. The number of farmers contracted by BAT in Kenya increased by 67% from 7,000 in 1972 to 11,000 in 1991, and by 36% from 1991 to 1993. As the number of tobacco farms increased in Kenya, the average per capita incomes decreased 67% from 1971 to 1991. In Migori, Kenya, where BAT is based, 52% of the population suffer from chronic or acute hunger and malnutrition. Food production in the major tobacco-growing areas has decreased as farmers have shifted from food crops to tobacco for BAT and other companies, increasing the income vulnerability for the farmers households. According to Kenya’s Green Belt Movement, “Many of the farmers were forced to switch from producing food, most commonly maize to growing tobacco, in the case of [BAT]. Now that they can no longer grow maize for personal use, and the return on the hard labor given to BAT are extremely low, [farmers] are now unable to either produce food crops to eat or buy food due to their low returns.” Bonded labor, also called debt servitude, in tobacco farming exists in Brazil, Malawi, Uganda, India, and other developing countries. The United Nations Supplementary Convention on the Abolition of Slavery, the Slave Trade, and Institutions and Practices Similar to Slavery defines bonded labor as “the status or condition arising from a pledge by a debtor of his personal services or those of a person under his control as security for a debt if the value of those services as reasonably assessed is not applied towards the liquidation of the debt or the length and nature of those services are not respectively limited and defined.” Bonded labor occurs in tobacco farming when a person who wants a loan but has no security to obtain a loan agrees to provide his labor or someone under his control as security to obtain a loan.