Biological efficacy of herbicides: propoxycarbazone-sodium (Attribut 70 WG) and sulfosulfuron (Apyros 75 WG) applied with adjuvants was estimated in the field, greenhouse and laboratory experiments. An addition of adjuvants to herbicides Attribut 70 WG and Apyros 75 WG had a positive influence on physical characteristics of tank mixture, herbicidal effect, and the increase of winter wheat grain yield. Ammonium nitrate used as an adjuvant showed the weakest effect. The lowest grain yield was obtained after using the preparations Attribut 70 WG and Apyros 75 WG without adjuvant. Th eoil adjuvants, Adbios 85 SL, A ero 030 SL, Atpolan 80 EC and Olbras 88 EC influenced in a similar manner the activity of tested herbicides. Obtained herbicidal effect, the amount of yield and elements of yield structure were differentiated after joint application of herbicides with adjuvants. The herbicides protected plantations of winter wheat against couch grass (Agropyron repens) during the whole vegetative season. However the herbicide Attribut 70 WG was more effective in controlling regrowth of couch grass after harvest, as compared to Apyros 75 WG. On the other hand, Apyros 75 WG controlled somewhat better broadleaf weeds. Also differences in carryover effect occurred. On the sites after propoxycarbazone–sodium application winter oilseed rape, spring oilseed rape and sugar beet should not be cultivated. On the sites after cereals that were protected against weeds with sulfosulfuron only cultivation of winter oilseed rape should not be recommended, however spring oilseed rape and sugar beet can be grown

Weeds in sweet corn reduce the yield and are economically more harmful than other pests. The aim of this study was to evaluate the effects of mechanical weed control and efficacy of pre- and postemergence applied herbicides in sweet corn, and their influence on weed control expressed by various indices, corncob yield and net return. Field studies were carried out with preemergence thiencarbazone-methyl + isoxaflutole (at 29.7 + 74.3 g · ha ^–1), postemergence S-metolachlor + terbuthylazine (937.5 + 562.5 g · ha ^–1), mesotrione + terbuthylazine (100 + 652 g · ha ^–1), terbuthylazine + mesotrione + S-metolachlor (656.3 + + 131.3 + 1093.8 g · ha ^–1), weed free (WF, hand weeding), and mechanical weeding (MW, hoeing) to assess weed control, corncob yield and net return. Variability in potential yield losses was observed between years due to weather conditions at the level of 30 to even 93%. Hand weeding was the most effective, but it is expensive and needs is labour consuming, unlike mechanical weeding which was the cheapest but simultaneously the least effective. Among pre- and postemergence applied herbicides, a mixture of terbuthylazine + mesotrione + S-metolachlor was the most efficacious weed control treatment. It gave high corncob yield and economic net return.

The evaluation of effect of the grass and broadleaf weed control of different mixture rates of mesotrione plus pethoxamid and terbuthylazine applied postemergence in maize was conducted in the field experiments during the 2005 and 2006 growing seasons. There was no phytotoxicity observed on maize after herbicide treatments. Herbicide mixture provided higher levels of Echinochloa crus-galii (L.) Beauv. control than mesotrione used alone. In the postemergence trials, the broadleaf weeds, except Chenopodium album L., were not well controlled by the mesotrione-alone treatment. The addition of pethoxamid plus terbuthylazine to mesotrione significantly improved the control of broadleaf weeds. Mesotrione and mesotrione plus pethoxamid and terbuthylazine treated plots were always among the highest yielding as compared to untreated plots. Any reductions in cob and grain yield were always associated with high weed fresh matter yields indicating that it was the weed competition that led to reduced yield and not herbicide phytotoxicity.

Digitaria insularis (sourgrass) is a monocotyledon weed of difficult control and high invasive behavior. Atrazine is widely applied in the Americas to control weeds in maize culture, but its efficiency against D. insularis is limited. The incorporation of atrazine into poly(epsilon-caprolactone) nanocapsules increased the herbicidal activity against susceptible weeds; however, the potential of this nanoformulation to control atrazine-tolerant weeds including D. insularis has not yet been tested. Here, we evaluated the post-emergent herbicidal activity of nanoatrazine against D. insularis plants during initial developmental stages. The study was carried out in a greenhouse, using pots filled with clay soil. Plants with two or four expanded leaves were treated with conventional or nanoencapsulated atrazine at 50 or 100% of the recommended dosage (1,000 or 2,000 g ∙ ha−1), followed by the evaluation of physiological, growth, and control parameters of the plants. Compared with conventional herbicide, both dosages of nanoatrazine induced greater and faster inhibition of D. insularis photosystem II activity at both developmental stages. Atrazine nanoencapsulation also improved the control of D. insularis plants, especially in the stage with two expanded leaves. In addition, nanoatrazine led to higher decreases of dry weight of fourleaved plants than atrazine. The use of the half-dosage of nanoatrazine was equally or more efficient in affecting most of the evaluated parameters than the conventional formulation at full dosage. Overall, these results suggest that the nanoencapsulation of atrazine potentiated its post-emergent herbicidal activity against D. insularis plants at initial developmental stages, favoring the control of this atrazine-tolerant weed.

The studies were conducted from 2012 to 2015 at the National Institute of Horticultural Research in Skierniewice, Poland. The aim of the research was to determine the yield of Chinese cabbage, its storage ability and nutritional value, depending on weed management methods used during cultivation. In the field experiments the following methods were compared: mechanical treatments, mechanical treatments + growth stimulators, soil mulching with black polypropylene, black polyethylene and biodegradable foil and hand weeding. After harvest the Chinese cabbage was stored at 0–2°C for 125–126 days depending on the year and after storage marketable and rotten heads were sorted. The percent of yellowed, rotten leaves in the total mass of the stored heads was also determined, as well as the natural weight loss. The chemical composition of Chinese cabbage was analyzed after harvest and after storage. The analyses included: dry matter, total sugars, vitamin C and soluble phenol content. After harvest the highest yield of Chinese cabbage grown in black polyethylene mulch was obtained. After storage the highest yield of marketable heads from cabbage mechanically weeded with additional application of biostimulator AlfaMax during cultivation was obtained. Chemical analyses showed that after harvest the highest dry matter, total sugars and vitamin C content were found in Chinese cabbage mechanically weeded and soluble phenols were the highest in non-weeded Chinese cabbage. After storage the highest content of dry matter was recorded in non-weeded Chinese cabbage, while total sugars were the highest in cabbage mulched with black polyethylene and biodegradable foil. Vitamin C was the highest in mechanically weeded and soluble phenols were the highest in hand-weeded cabbage.

Redroot pigweed (Amaranthus retroflexus L). is a broadleaf weed in autumn crop fields in Russia. Four field experiments were performed in Stalskiy region, southern Russia in two growing seasons, 2016 and 2017, to investigate the effects of postemergence applications of applied alone or in tank mixtures in winter wheat cultivars Tanya and Bagrat. Redroot pigweed control was greatest with tribenuron and all herbicide treatments containing tribenuron. The lowest redroot pigweed control was with aminopyralid/florasulam (study 1) and triasulfuron (study 2), respectively, whereas redroot pigweed had intermediate responses to the other examined herbicides. Tribenuron plus fluroxypyr sprayed on wheat cultivar ‘Tanya’, and tribenuron plus triasulfuron on wheat cultivar ‘Bagrat’ resulted in increased wheat grain yields. Overall, tribenuron and herbicides containing tribenuron provided the most efficient redroot pigweed control compared with the other herbicides and consistently maintained optimal winter wheat yields. Tribenuron could ameliorate redroot resistance to herbicides in wheat fields in southern Russia.

Currently more and more research is being done on integrated weed management to reduce or avoid herbicide use. Some growers are already using isotherapic dilutions to control weeds in organic farming. Isotherapy is different from homeopathy because it uses diluted and potentized (succussed) solutions of alcoholic macerate of the very pest causing health troubles. We set up a germination experiment to test if isotherapic dilutions of leaf macerate of annual ryegrass affect the dynamics of its seed germination in Petri dishes. Our results were diverse, from no effect to 10% more growing degree days necessary to reach 50% germination. It is doubtful that so low an effect will contribute to integrated weed management unless the slightly delayed germination triggers secondary effects at other life stages. This is in accordance with the scientific literature on that topic: two-fifths of the reports showed no effect, two-fifths resulted in positive responses and one-fifth had diverse responses for the criteria tested.

Nozzle type and herbicide application timing can affect herbicide efficacy. Prickly sida ( Sida spinosa) and barnyardgrass ( Echinochloa crus-galli) are problematic weeds in eastern Mississippi cotton production and have reduced yield in recent years. Field studies were conducted at two locations – Brooksville, MS (2018, 2019) and Starkville, MS (2019) to understand the nozzle type and herbicide application timing effects on prickly sida and barnyardgrass control in cotton. Studies also compared applications made by an eight-nozzle tractor-mounted sprayer with a four-nozzle backpack sprayer. Herbicide applications were made at four timings: preemergence (PRE), early-postemergence (EPOST), mid-postemergence (MPOST), and late-postemergence (LPOST) corresponding to the preemergence (immediately after planting), two-to-three leaf, four-to-six leaf, and early-bloom stages, respectively. Treatments were made at 140 l · ha−1 applied at each growth stage, with nozzle type and sprayer as variables by each timing. Results showed no differences in treatments applied with backpack and tractor-mounted sprayers. Control of barnyardgrass was significantly affected by nozzle type, but control of prickly sida was not significantly influenced by nozzle type. In all three site-years, plots receiving a MPOST only herbicide application resulted in less weed control than areas receiving a two-pass POST herbicide program. Cotton yield was significantly affected by the herbicide program at one site-year, but was not significantly affected by the herbicide program except where cotton injury exceeded 15%. A two- or three-pass herbicide program was most effective in controlling prickly sida and barnyardgrass in Mississippi cotton.