Two field experimental trials were carried out in central Italy, in 2005 and 2006, on biomass sorghum [Sorghum bicolor (L.) Moench] in order to assess weed control efficacy and selectivity to the crop of some pre- and post-emergence herbicides applied at different doses and in different mixtures. All herbicides showed good selectivity to the crop, although postemergence treatments showed higher transitory phytotoxicity effects than pre-emergence treatments, especially when high temperatures occurred after treatments, decreasing the selectivity of leaf herbicides (i.e. MCPA, 2,4-D, bromoxynil and dicamba). Considering pre-emergence applications, terbuthylazine alone against broadleaves or in mixtures at low doses with s-metolachlor against mixed infestations (grasses + broadleaves), seemed to be the best options to obtain a good selectivity to the sorghum and a high weed control level. Aclonifen showed some limits in terms of weed spectrum and could be recommended only against simplified broadleaf weed infestations without the presence of less susceptible weeds, like Amaranthus retroflexus, Portulaca oleracea and Solanum nigrum. Propachlor seemed not to be advisable due to the low efficacy against all the major broadleaf warmseason weed species in the Mediterranean areas. Considering post-emergence applications, all treatments gave quite similar results in terms of weed control, although, the mixture of terbuthylazine + bromoxynil seemed to be the best option due to bromoxinil’s higher efficacy than other foliar herbicides, such as MCPA, 2,4-D and dicamba, which can increase the efficacy of terbuthylazine alone especially under dry weather conditions. There were no significant differences in sorghum biomass between herbicide treatments, although, the more selective pre-emergence treatments showed, on average, a higher biomass yield value than the less selective post-emergence treatments. For these reasons, biomass values seemed to be more related to herbicide selectivity than to herbicide efficacy, especially in cases of scarce competitiveness of weed flora.

The aim of performed research was to evaluate weed seedbank in soil under the influence of four different winter wheat tillage systems. Winter wheat was grown in the following cultivation systems: A – monoculture with direct drilling into white clover mulch; B – monoculture with direct drilling into wheat stubble; C – monoculture with conventional tillage; D – crop rotation with conventional tillage. It was shown that pre-sowing wheat tillage had a more considerable effect on weed species and weed seedbank in soil than type of crop rotation. The least seedbank was observed when plough system was replaced by direct drilling. In the soil layer of 0–20 cm, under wheat no-plough tillage, 20.3% less weed diaspores wasfound compared to monoculture with plough tillage and by 40.1% lessthan in crop rotation. The plough tillage increased amount of weed diaspores in the whole plough layer, while direct drilling increased it only in 0–1 cm of soil layer. After direct drilling of wheat into stubble (B) the number of weed diaspores in 1 dcm³ of soil in 0–1 cm layer was over twofold higher than in direct sowing in mulch (A), and threefold higher than in crop rotation (D) and almost six times higher than in wheat monoculture with conventional tillage (C). Dominating weed species in the soil over the types of wheat cultivation systems were: Chenopodium album L., Amaranthus retroflexus L., Apera spica-venti L., Lamium purpureum L., and Viola arvensis Murr.

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 are one of the most important limiting factors in the production of chickpea (Cicer arietinum) in Iran, especially in autumn sown chickpea. Weed density and biomass in autumn chickpea are seven and two and a half times higher than the spring chickpea, respectively. The weed damage to chickpea in Tabriz, Kermanshah and West Azerbaijan was estimated at 48.3, 57 and 36%, respectively. Sixty-four weed species were identified in chickpea fields. Convolvulus arvensis L. and Galium tricornutum Dandy have the highest presence in chickpea fields. Pyridate and linuron are the only herbicides registered for use in chickpea fields in Iran. However, research results show that fomesafen and isoxaflutole are the most appropriate herbicides for chickpea fields. Oxyfluorfen, imazethapyr, metribuzin, trifluralin, simazine, terbutryn and pendimethalin are the major herbicides studied in weed control research. The combination of herbicides and mechanical control is one of the effective methods to reduce weeds. Hand weeding and cultivation between rows are the most effective mechanical methods of weed control. High nitrogen enhances weed dry weight. Safflower and barley residues reduce weed populations and biomass. Barley-chickpea and wheat-chickpea intercropping systems increase chickpea yield together with proper weed control. In future research, more attention should be paid to surfactants to reduce the use of herbicides, rotation crops and integrated weed management in chickpea.

There are few reports in literature about the selectivity of postemergence application of herbicides for the control of eudicotyledon weeds (broadleaf) in chickpea. For this reason, the aim of this study was to investigate the selectivity of diphenyl-ether herbicides in chickpea influenced by the herbicides and application rates. A field experiment was conducted from February to June 2017 in Urutaí, state of Goiás, Brazil. Cultivar BRS Aleppo was used in the experiment. The experiment was set up in a randomized block design with 2 × 3 + 1 factorial arrangement and three replications. The first factor was herbicides (fomesafen and lactofen) with the second factor being herbicide rate (50, 75, and 100% of referenced rate) plus an untreated check as a comparison. The applied rates of herbicides were 250 and 180 g ⋅ ha–1 of fomesafen and lactofen, respectively. The selectivity of herbicides was evaluated according to agronomic characteristics (plant population, height, dry matter, number of pods per plant and 100-grain weight) and yields. Both herbicides, regardless of dosage, were selective in chickpea cultivation, even exhibiting leaf necrosis symptoms with visible injuries below 20% with no effect on yield.

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.

Between 2004 and 2017, multiple studies on the herbicide resistance of weeds were conducted by the Institute of Plant Protection – National Research Institute in Poland. Weed seeds, collected from fields located in various regions of Poland where herbicide use was ineffective, were used in studies conducted under greenhouse conditions. A total of 261 loose silky bent (Apera spica-venti L.) samples were found to be herbicide resistant, which translates to 52.4% of the fields under study. Nearly 50% of the analyzed samples exhibited resistance to sulfonylurea herbicides. Resistance to acetyl CoA carboxylase (ACCase) inhibitors was found in 18 fields, whereas resistance to photosystem II (PSII) inhibitors (isoproturon) was found in 12 fields. Herbicide resistance of blackgrass (Alopecurus myosuroides Huds.) occurred in 26 of the fields under study. In addition, resistance of wild oat (Avena fatua L.) to acetyl CoA carboxylase inhibitors occurred in 10 spring cereal crops. In the case of winter wheat, resistance of cornflower (Centaurea cyanus L.) to tribenuron-methyl occurred in 23 fields. Scentless chamomile (Matricaria inodora L.) and field poppy (Papaver rhoeas L.) were resistant to tribenuron-methyl in four and three fields, respectively, of winter wheat. In the case of sugar beet, three biotypes of fat hen (Chenopodium album L.) and two biotypes of redroot amaranth (Amaranthus retroflexus L.) were resistant to metamitron. Horseweed (Conyza canadensis L.), which grows on railway tracks, exhibited resistance to glyphosate. This paper reviews all studies conducted in Poland on weed resistance. Based on the results, maps of weed resistance in Poland were created.

Two field experiments were established at the Agricultural Experimental Station of the National Research Centre at Nubaria, Beheira Governorate, Egypt to study the herbicidal potential of the leaf extract of Eucalyptus citriodora at 5, 10, 15, 20 and 25% compared to two hand hoeing, unweeded treatments and the chemical herbicides Bentazon + Clethodium, Bentazon + Fluazifop-P-butyl and Butralin on pea plants and associated weeds. The results indicated that two hand hoeing achieved the maximum weed depression as expressed by the dry matter of total weeds. The dry matter of total weeds decreased by 95.08 to 94.77% as compared with unweeded treatment 50 and 70 days after sowing (DAS) followed by Butraline (93.93–94.65%), Bentazon + Clethodium (93.26–94.07%), Bentazon + Fluazifop--P-butyl (91.82–92.77%) and leaf extract of Eucalyptus at 25% (91.61–91.95%). Furthermore, the reduction in weed development was accompanied by enhanced pea growth and yield. The results revealed that two hand hoeing was the best treatment to increase plant height, shoot dry weight and SPAD value at 50 and 70 DAS. Also, two hand hoeing produced the maximum values of pod length and number of seeds/pod. The results also indicated that Bentazon + Clethodium treatment gave observable values [recorded 72.96% in pod yield (ton ⋅ fed.–1) over that of unweeded control] of number of pod/plant, weight of pod/plant, seed yield/fed and protein percentage. Also, the results revealed great increases in the growth of pea as well as yield due to treatment with E. citriodora dry leaf extract at 25%. [recorded 64.8% in in pod yield (ton ⋅ fed.–1) over that of unweeded control]. So, the results indicated using Bentazon + Clethodium as well as E. citriodora dry leaf extract at 25% to control weeds associated with pea plants. The authors suggested application of E. citriodora dry leaf extract at 25% in controlling weeds associated with pea plants as a safe method that avoids environmental contamination.

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.

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.

This study was conducted to predict the yield and biomass of lentil (Lens culinaris L.) affected by weeds using artificial neural network and multiple regression models. Systematic sampling was done at 184 sampling points at the 8-leaf to early-flowering and at lentil maturity. The weed density and height as well as canopy cover of the weeds and lentil were measured in the first sampling stage. In addition, weed species richness, diversity and evenness were calculated. The measured variables in the first sampling stage were considered as predictive variables. In the second sampling stage, lentil yield and biomass dry weight were recorded at the same sampling points as the first sampling stage. The lentil yield and biomass were considered as dependent variables. The model input data included the total raw and standardized variables of the first sampling stage, as well as the raw and standardized variables with a significant relationship to the lentil yield and biomass extracted from stepwise regression and correlation methods. The results showed that neural network prediction accuracy was significantly more than multiple regression. The best network in predicting yield of lentil was the principal component analysis network (PCA), made from total standardized data, with a correlation coefficient of 80% and normalized root mean square error of 5.85%. These values in the best network (a PCA neural network made from standardized data with significant relationship to lentil biomass) were 79% and 11.36% for lentil biomass prediction, respectively. Our results generally showed that the neural network approach could be used effectively in lentil yield prediction under weed interference conditions.

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.