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Managing Greens and Tees
Published in L.B. (Bert) McCarty, Golf Turf Management, 2018
A major limitation to seashore paspalum is the lack of labeled selective herbicides as many commercial products are too phytotoxic. Weeds commonly associated with paspalum include crabgrass, goosegrass, annual bluegrass, purple and yellow nutsedge, kyllinga, bermudagrass, torpedograss, bahiagrass, dallisgrass, vaseygrass, foxtail, broadleaf signalgrass, barnyardgrass, and various broadleaf weeds (Figure 10.40). Preemergence herbicides currently safe on paspalum include benefin, benefin plus trifluralin, bensulide, dithiopyr, isoxaben, DCPA, metolachlor, granular oxadiazon, pendimethalin, prodiamine, and pronamide. “Marginally” tolerant preemergence herbicides include oryzalin (retards green-up), atrazine, simazine, and liquid formulations of oxadiazon. Tolerant postemergence herbicides include bentazon, carfentrazone, sulfentrazone, ethofumesate, imazaquin, quinclorac, metsulfuron-methyl, pronamide, and halosulfuron. Moderate postemergence herbicide tolerance includes three-way mixtures of 2,4-D plus dicamba plus MCPP, fluroxypyr, dicamba, metribuzin, sulfosulfuron, and 2,4-D amine. Lower rates should be used with these products, especially as temperatures increase. Herbicides with low tolerance by paspalum include asulam, arsenicals, foramsulfuron, clopyralid, triclopyr, trifloxysulfuron, diclofop-methyl, sethoxydim, fluazifop, clethodim, and fenoxaprop. As specific cultivars and environmental conditions often greatly influence herbicide tolerance, a small test area should always be available prior to widespread application.
Anaerobic digestion of calotropis procera for biogas production in arid and semi-arid regions: A case study of Chad
Published in Cogent Engineering, 2022
Stephanie Solal Djimtoingar, Nana Sarfo Agyemang Derkyi, Francis Atta Kuranchie, Khadija Sarquah
To fight the spread of Calotropis Procera, invaded regions are adopting various management practices with constant monitoring over the following years to prevent the growth of new seedlings. These management methods are mechanical removal, which consists of extracting the whole plant (including the roots) to prevent reproduction. According to Kaur et al. (2021), this technique allows 72% removal efficiency although it results in new seedling emerging. Chemical removal is the use of pesticides such as 2,4-D butyl ester, fluroxypyr, triclopyr and triclopyr/picloram…. This process reached an 80% efficiency on plants below 5 cm close to the ground (Vitelli et al., 2008). Biological removal consists of using biocontrol agents to inhibit the growth of the plant. These control agents consist of insects (up to 65 species), mites (5 species) and fungal pests (Kaur et al., 2021). According to (S. Ali et al., 2020), Dacus persicus Hende, a fruit fly is a potential biocontrol agent causing up to 100% damage to young seeds.
Toxicity of herbicides to cyanobacteria and phytoplankton species of the San Francisco Estuary and Sacramento-San Joaquin River Delta, California, USA
Published in Journal of Environmental Science and Health, Part A, 2020
Chelsea H. Lam, Tomofumi Kurobe, Peggy W. Lehman, Mine Berg, Bruce G. Hammock, Marie E. Stillway, Pramod K. Pandey, Swee J. Teh
There are many mechanisms by which phytoplankton and cyanobacteria taxa could be resistant to the effects of herbicides. Resistant taxa could take up less chemical, sequester the chemical into vacuoles or cell compartments where the chemical does not exert toxic effects, degrade the chemical to nontoxic metabolites, have resistant enzymes, or employ other modifications to confer resistance. For instance, Chlamydomonas reinhardtii was found to tolerate extremely high concentrations of the broadleaf herbicide fluroxypyr (up to 0.5 mg L−1) by accumulation and rapid biodegradation of the herbicide.[64] Because of their ability to use these mechanisms, it is not surprising to see variation in resistance to herbicides between plankton species. Even within the same genus, species responses can differ greatly. For instance, one study found that the growth of the cyanobacterium Oscillatoria agardhii was inhibited by 40 µg L−1 of fluridone, while another study found the growth of O. chalybea, was not affected by fluridone up to 3293 µg L−1.[59,60] Fluridone resistance due to mutations in the phytoene desaturase enzyme are reported in hydrilla plants.[65,66] Therefore, the three species tested for this study almost certainly do not represent the full range of responses to herbicides within the cyanobacteria, diatom, and green algae taxa.
From peaks to prairies: a time-of-travel synoptic survey of pesticides in watersheds of southern Alberta, Canada
Published in Inland Waters, 2019
Claudia Sheedy, Natalie Kromrey, Denise Nilsson, Tyler Armitage
Pesticide physicochemical properties are factors that can impact detection frequency (Gassman et al. 2015). Pesticides detected most frequently (2,4-D, dicamba, MCPA, mecoprop, fluroxypyr, and clopyralid) have short half-lives (25 d or less) but high water solubility and large sales estimates (Supplement S8). These pesticides belong to the phenoxy (2,4-D, mecoprop, MCPA), benzoic acid (dicamba), and pyridine (fluroxypyr, clopyralid) families, which all have the same mode of action (auxin mimic; Grossman 2010). Three other herbicides with this mode of action were detected at lower detection frequency, including picloram (3%), dichlorprop (1%), and triclopyr (1%). In addition, 2,4-DCP is a degradation product of 2,4-D. The log Koc values for these compounds range from 0.7 to 2.0, so this property alone could not explain the detection frequencies observed. A study of 2,4-D and MCPA in river sediments collected from Manitoba showed high detection frequency (83%) and concentrations of MCPA, ranging from nondetected to 270 ng/kg, and lower detection frequency (25%) and levels of 2,4-D (maximum 28 ng/kg; Gamhewage et al. 2019).