Herbicide-Resistant Crops: Utilities and Limitations for Herbicide-Resistant Weed Management

Since 1996, genetically modified herbicide-resistant (HR) crops, particularly glyphosate-resistant (GR) crops, have transformed the tactics that corn, soybean, and cotton growers use to manage weeds. The use of GR crops continues to grow, but weeds are adapting to the common practice of using only glyphosate to control weeds. Growers using only a single mode of action to manage weeds need to change to a more diverse array of herbicidal, mechanical, and cultural practices to maintain the effectiveness of glyphosate. Unfortunately, the introduction of GR crops and the high initial efficacy of glyphosate often lead to a decline in the use of other herbicide options and less investment by industry to discover new herbicide active ingredients. With some exceptions, most growers can still manage their weed problems with currently available selective and HR crop-enabled herbicides. However, current crop management systems are in jeopardy given the pace at which weed populations are evolving glyphosate resistance. New HR crop technologies will expand the utility of currently available herbicides and enable new interim solutions for growers to manage HR weeds, but will not replace the long-term need to diversify weed management tactics and discover herbicides with new modes of action. This paper reviews the strengths and weaknesses of anticipated weed management options and the best management practices that growers need to implement in HR crops to maximize the long-term benefits of current technologies and reduce weed shifts to difficult-to-control and HR weeds

A randomized study to evaluate the effect of exercise on fatigue in people with relapsing–remitting multiple sclerosis treated with fingolimod

Background Fatigue is a major symptom of multiple sclerosis (MS) in patients, and it has been shown to improve with physical exercise. Although fingolimod might lessen fatigue, it is unclear how patients treated with fingolimod react to physical activity regarding fatigue. Objective This study evaluated the effect of an exercise intervention on fatigue in relapsing–remitting MS patients receiving fingolimod. Methods People with MS (PwMS) were randomized to either a structured internet-based exercise program (e-training) or no e-training intervention. The primary endpoint was the change in the Modified Fatigue Impact Scale (mFIS) after six months. Results The primary analysis showed no statistically significant difference between groups in the mFIS change. Subgroup analyses revealed a beneficial effect of physical exercise for PwMS with low aerobic capacity and with low aerobic capacity plus more severe fatigue. The incidence of adverse events was similar in both groups. No cardiovascular events were reported. The majority of PwMS were relapse free. Conclusion Physical exercise benefits on fatigue may depend on the physical capacity of the patient and requires individualized training. Consistent with previous studies, these results suggest that physical exercise generally does not impose a risk and that this holds true also for patients receiving fingolimod