The Northern Great Plains of the United States is a major production region for organic pulse crops that are prone to yield losses due to weeds. Weed management in organic systems relies on the integration of several tactics to stack additive effects and for redundancy to deal with variable efficacy of individual weed management practices. To address the need for effective, integrated weed management, we conducted a 2-yr trial that evaluated the effects of planting date, seeding rate, and preemergent weed control practices (shallow tillage and flame weeding) on weed biomass, crop density, and yield in organically managed chickpea (Cicer arietinum L.) in Montana. Stacking weed management practices increased yields. Early planting had the largest effects on yields, increasing them by 1.8- to 3.6-fold compared with planting 10 to 14 d later. Increasing the seeding rate from the standard rate (43 viable seeds m−2) by 50% increased yields by 47% from 889 to 1,304 kg ha−1. Both preemergent weed control practices increased yields by 40% to 50 % relative to the non-weeded controls. By integrating all three practices, yields of organic chickpea increased greater than 6-fold from 318 kg ha−1 in the controls to 2,006 kg ha−1. The effects of weed control treatments on midseason weed biomass were complex and variable. Although efficacy of the cultural (seeding rate and planting date) and physical (preemergent) treatments on weed biomass varied between years and when combined with other treatments, their full integration, that is, early planted, at higher seeding rate, and preemergent weed control, produced consistently lower weed biomass (84% reduction on average) compared with the standard grower practice (later planting, standard seeding rate, no preemergent weed control). The results lend support to the concept of integrating multiple weed management practices to achieve weed control and high yields in organically managed crops.

In Oklahoma, downy brome and cheat are difficult-to-control winter annual grasses. In the past, cheat infested most of the winter wheat hectares harvested in Oklahoma. Biotypes that are cross-resistant to acetolactate synthase–inhibiting herbicides have left growers with minimal management options for conventional and herbicide-tolerant systems. Field trials near Lahoma, Oklahoma, in 2019–2020 and 2020–2021 evaluated integrated management of cheat and downy brome using three strategies: planting date (optimal, delayed, and late), cultivar selection (high and low competitiveness), and herbicide choice (no herbicide, sulfosulfuron at 35.2 g ai ha−1 and pyroxsulam at 18.4 g ai ha−1). Visual control, weed species present, wheat biomass at heading, and grain yield data were collected. In 2019–2020, 8 to 9 wk after treatment, visual control increased by 15% with the delayed planting compared with the optimal planting date and 14% with the late planting date. In 2020–2021, similar control (∼99%) was recorded for delayed and late plantings with 23% greater control than the optimal timing. Due to a lack of weed coverage, weed biomass in 2019–2020 had no response to planting date, cultivar, or herbicide treatment. Downy brome biomass during 2020–2021 was approximately 90% lower with delayed to late planting dates than the optimal planting date. In the same year, downy brome and cheat biomass were low (≤0.4 and 0.2 g m−2) and 98% less after an herbicide application than a nontreated area. Wheat grain yield at the optimal planting date was greater than yields from delayed and late plantings in 2019–2020. A delay in planting from the optimal date to delayed or late timings decreased wheat yield by 14% and 21%, respectively. In 2020–2021, wheat yield from the late planting was reduced by 57% compared with the optimal planting yield. Delaying the planting date and the use of a common herbicide can suppress cheat and downy brome, but a decline in wheat yield may occur.

In New Mexico chile pepper production, pendimethalin is traditionally applied shortly after crop thinning, which is 9 to 10 wk after crop seeding. Pendimethalin applications before crop thinning may be a method for controlling early-season weeds in chile pepper; however, chile pepper tolerance to early-season applications of pendimethalin is poorly understood. We conducted a greenhouse study to evaluate young chile pepper responses to pendimethalin. We also conducted a field study to determine weed and chile pepper responses to early-season, postemergence-directed pendimethalin in combination with herbicides registered for preemergence applications. The greenhouse study included three treatments administered when chile pepper was at the four-leaf stage: (i) pendimethalin applied to foliage and soil, (ii) pendimethalin applied to soil only, and (iii) a nontreated control. The field study included four treatments: (i) preemergence applications of napropamide followed by postemergence-directed pendimethalin at 5 wk after crop seeding, (ii) preemergence applications of clomazone followed by postemergence-directed pendimethalin at 5 wk after crop seeding, (iii) postemergence-directed pendimethalin without preemergence herbicides, and (iv) nontreated, weed-free control. We conducted the field study at two sites that differed in soil texture. Pendimethalin application rates were maximum labeled rates for the specific soil. Results from the greenhouse study indicated that pendimethalin applied to foliage and soil stunted two of five cultivars, whereas pendimethalin applied to soil did not affect chile pepper height, fresh weight, dry weight, or root area. Results from the field study indicated that postemergence-directed pendimethalin did not affect chile pepper height or fruit yield, or cause visible symptoms of herbicide injury. Postemergence-directed pendimethalin reduced the densities of weeds, including junglerice. The results of this study indicate that postemergence-directed applications of pendimethalin at 5 wk after crop seeding do not cause crop injury or yield loss in chile pepper, while providing some weed control benefits.

An important route of introduction of some nonnative species that subsequently become invasive in the United States is through horticulture. One such plant is Euonymus fortunei (Turcz.) Hand.-Maz., commonly known as wintercreeper, an evergreen groundcover with more than 52 different horticultural varieties, which is still sold at many plant nurseries and garden centers in the midwestern United States. Although several states have recognized E. fortunei as an invasive species, it is unknown how its escape from cultivation has occurred and even the identity of spreading populations, including whether hybrids or cultivars are involved. Using codominant microsatellite markers, we sampled multiple invasive populations in Ohio, Kentucky, Kansas, and Minnesota and compared their genotypes with commercially available cultivars to determine how spread has occurred. All samples collected from invasive populations were genetically identical to one another and matched perfectly with the ‘Coloratus’ cultivar, the only cultivar to exhibit polyploidy. The data also suggest that E. fortunei may potentially reproduce via apomixis and/or clonally through propagule fragments, which can quickly fix favorable genotypes within a population. To curb continued invasive spread, we suggest that Coloratus be removed from commercial sale and distribution. We also propose that land managers, horticultural and landscaping businesses, and governmental agencies carefully monitor other Euonymus cultivars for invasive potential and spread.

The effects of three seeding rates (250, 350 and 450 seeds/m2), six applied N rates (40, 70, 100, 130, 160 and 190 kg N/ha) and the application of plant growth regulator on the grain quality of two spring oat cultivars (Husky and Keely) were evaluated at four spring-sown sites over a 3-year period (2016–2018). The same cultivars, seeding rates and five applied N rates (80, 110, 140, 170 and 200 kg N/ha) were evaluated at three winter-sown sites, in 2017–2019. Keely had a significantly higher kernel content (KC) in spring (0.7%) and winter-sown (0.6%) oats. Specific weight (SW) decreased as N rate increased in spring-sown crops (1 kg/hl) with no effect observed in winter-sown oats. Hullability (HB) increased (0.92%) in spring-sown crops as N rate increased with a reduction (0.9%) observed when winter-sown. Increases in grain protein percentage (GPP) were observed in spring (1.8%) and winter (1.2%) sowings in response to N rate. The application of plant growth regulator reduced SW (0.4 kg/hl), GPP (0.3%), KC (0.6%) with no effect on HB. Kernel size was highly responsive too applied N rate, with reductions in grains >2.5 mm and increases in grains of smaller size observed as N rate increased. HB had a marked relationship to kernel size with GP inconsistently linked to SW. The results of this study suggest that cultivar, N rate and PGR application are of importance to milling quality and that changes in grain size in response to agronomic practices contribute to changes in specific weight and hullability.

Factorial experiments were carried out on spring- and winter-sown oat crops in Ireland in 2016–2019 to identify plant responses in yield formation and grain filling procedures. Two cultivars (Husky and Keely), three seed rates (250, 350 and 450 seeds/m2), six applied nitrogen (N) rates (40, 70, 100, 130, 160 and 190 kg N/ha) with a plant growth regulator (PGR) were examined in spring and winter sowings, using the same cultivars at five rates of applied N (80, 110, 140, 170 and 200 kg N/ha). The applied N rate and seed rate significantly (P < 0.05) modified the yield components determining grains/m2 in spring- and winter-sown crops with increases in panicle number of key importance. Increases were also observed in the proportion of primary grain by weight (0.9–1.6%) and number (0.7–1.4%) ratios in spring-sown crops in response to applied N rate, with winter-sown crops exhibiting a more consistent pattern of grain fill. Seed rate and PGR application had minor effects on yield components and panicle conformation. Grain fill procedures played an important role in the maximization of grain yield under seasonal conditions. Significant positive correlations were observed between the number of aborted grain sites and yield under drought conditions (0.22), with negative associations observed in near-optimal conditions (−0.22 to −0.41). Agronomic effects on grain site abortion were minimal in comparison with seasonal effects. In seasons characterized by cool, consistent conditions, grain yield was maximized by the utilization of all available grain sites. Where assimilate shortages were encountered during grain fill the abortion of grains sites was positively associated with grain yield.

Table olives, a product of olive tree (Olea europaea L.), is an important fermented product of the Mediterranean Diet. Agronomical factors, particularly the cultivar, the ripening stage and the processing method employed are the main factors influencing the nutritional and non-nutritional composition of table olives and their organoleptic properties. The important nutritional value of this product is due to its richness in monounsaturated fat (MUFA), mainly oleic acid, fibre and vitamin E together with the presence of several phytochemicals. Among these, hydroxytyrosol (HT) is the major phenolic compound present in all types of table olives. There is a scarcity of in vitro, in vivo and human studies of table olives. This review focused comprehensively on the nutrients and bioactive compound content as well as the health benefits assigned to table olives. The possible health benefits associated with their consumption are thought to be primarily related to effects of MUFA on cardiovascular health, the antioxidant (AO) capacity of vitamin E and its role in protecting the body from oxidative damage and the anti-inflammatory and AO activities of HT. The influence of multiple factors on composition of the end product and the potential innovation in the production of table olives through the reduction of its final salt content was also discussed.

Florpyrauxifen-benzyl and quizalofop were available for POST applications in 2018; however, little is known about the response of acetyl-CoA carboxylase (ACCase)–resistant rice cultivars and advanced lines to POST herbicides. A field study was conducted in 2017 and 2018 at Stoneville, MS, to characterize the response of ACCase-resistant rice cultivars and advanced lines to POST applications of florpyrauxifen-benzyl. The imidazolinone-resistant (IR) rice cultivars ‘CL163’ and ‘CLXL 745’, and ACCase-resistant rice cultivars ‘PVL01’, ‘PVL013’, ‘PVL024-B’, ‘PVL038’, ‘PVL080’, and ‘PVL081’were treated with florpyrauxifen-benzyl at 0 (nontreated control for each cultivar) and 58 g ai ha–1 at the four-leaf to one-tiller (LPOST) growth stage. At 14 d after treatment (DAT), PVL01 was injured 5% to 6% greater than CLXL 745, PVL013, and PVL081; however, injury was ≤10% at that evaluation for all cultivars. Similarly, injury was ≤13% for all cultivars 28 DAT. Mature heights were reduced for all cultivars except PVL013 and PVL081. Rough rice yield was ≥100% of the control for all cultivars except PVL081, PVL013, and CL163. Results suggest that florpyrauxifen-benzyl can safely be applied POST to rice cultivars grown in Mississippi as well as ACCase-resistant cultivars that are currently under development.

Soybean [Glycine max (L.) Merr.] has recently become a popular rotational crop in the Canadian Northern Great Plains where herbicide-resistant (HR) soybean cultivars have been widely adopted. Intense reliance on herbicides has contributed to the development of HR weeds in soybean and other crops. Cultural weed management practices reduce the need for herbicides and lower the selection pressure for HR weed biotypes by improving the competitiveness of the crop. The effects of two row spacings, three target densities, and three cultivars on the critical weed-free period (CWFP) in soybean were evaluated as three separate experiments in southern Manitoba. In the row-spacing experiment, soybean grown in narrow rows shortened the CWFP by up to three soybean developmental stages at site-years with increased weed pressure. In the target density experiment, low-density soybean stands lengthened the CWFP by one soybean developmental stage compared with higher-density soybean stands. The effect of soybean cultivar varied among locations, yet tended to be consistent within location over the 2-yr study, suggesting that competitive ability in these soybean cultivars was linked to edaphic and/or environmental factors. Generally, the cultivar with the shortest days to maturity, which also had the shortest stature, consistently had a longer CWFP. Each of these cultural practices were effective at reducing the need for in-crop herbicide applications.

Weed-suppressive rice cultivars have the potential to reduce heavy reliance on synthetic herbicides in rice production. However, the economics of using weed-suppressive rice cultivars in conventional rice systems have not been fully evaluated. This study uses simulation and stochastic efficiency with respect to a function to rank weed-suppressive and weed-nonsuppressive rice cultivars under alternative herbicide intensity levels based on their certainty equivalents mapped across increasing levels of absolute risk aversion. The results indicate risk-averse rice producers would prefer to grow weed-suppressive cultivars using less herbicide inputs than what would be used to grow weed-nonsuppressive rice cultivars.

Benzobicyclon is the first 4-hydroxyphenylpyruvate dioxygenase-inhibiting herbicide pursued for commercial registration in U.S. rice production. A study was conducted in 2015 and 2016 to evaluate the response of eight rice cultivars to post-flood application timings of benzobicyclon at 494 g ai ha-1 (proposed 2X rate). ‘Caffey’, ‘CL151’, ‘CLXL745’, ‘Jupiter’, ‘LaKast’, ‘Mermentau’, ‘Roy J’, and ‘XL753’ were evaluated in response to applications of benzobicyclon. The highest level of visible injury was observed in LaKast at 7% in 2015. No visible injury was detected among other cultivars either year at 2 weeks after treatment. In 2015 and 2016, no more than a four-day delay to reach 50% heading occurred across all cultivars. Rough rice yield was not affected by any of the post-flood application timings of benzobicyclon. A second study was conducted in 2016 at three locations throughout Arkansas to investigate the tolerance of 19 tropical japonica (inbred and hybrid) and two indica inbred cultivars to a premix containing benzobicyclon at 494 g ai ha-1 and halosulfuron at 72 g ai ha-1 applied 1 week after flooding. The tropical japonica cultivars have excellent crop safety to benzobicyclon while application to the indica cultivars, Rondo and Purple Marker, expressed severe phytotoxicity. Benzobicyclon caused less than a 2 d delay in heading to the japonica cultivars. Rough rice yield of the tropical japonica cultivars was not affected by benzobicyclon while yields of both indica cultivars were negatively affected. Benzobicyclon can safely be applied to drill-seeded tropical japonica inbred and hybrid cultivars in a post-flood application without concerns for crop injury. Benzobicyclon should not be used on indica cultivars as it will cause severe injury, delayed heading, and yield loss.

Field experiments conducted in 1992 and 1993 evaluated differential response of 20 soybean cultivars to POST application of AC 263,222 or chlorimuron, as influenced by soil moisture. Natural rainfall was supplemented with overhead sprinkler irrigation to achieve three moisture regimes: excessive (12.5 cm/wk), optimum (5 cm/wk), and low (non-irrigated). Chlorimuron and AC 263,222 injured soybean. Excessive moisture did not increase soybean injury with chlorimuron for any of the cultivars tested compared to optimum moisture; however, 17 of 20 cultivars were injured more by AC 263,222 in combination with excessive moisture than optimum moisture. AC 263,222 reduced the height of five cultivars. Photosynthetic rate of several cultivars was reduced by both AC 263,222 and chlorimuron. Neither herbicide affected the number of nodes per main stem or seed weight; however, pod numbers were reduced for several cultivars with both herbicides. In the low moisture regime, AC 263,222 delayed the maturity of 18 of 20 cultivars with ‘Hutcheson’ maturity delayed 7.1 d. Excessive moisture when combined with AC 263,222 reduced yields for 12 cultivars, compared to five cultivars with chlorimuron. Under optimum moisture conditions, AC 263,222 reduced the yield of 10 cultivars, whereas chlorimuron reduced the yield of 9 cultivars. Low moisture stress only resulted in a yield reduction with 3 cultivars treated with AC 263,222.

The effect of soil residues of flumetsulam plus clopyralid on several vegetable crops grown in rotation with field corn was investigated over 2 yr. The effect of soil residues of flumetsulam plus clopyralid on sweet corn cultivars of varying sensitivity to acetolactate synthase (ALS)-inhibiting herbicide was also investigated. Flumetsulam plus clopyralid was applied preemergence (PRE) to field corn at 0, 50 + 135, and 100 + 270 g ai/ha, respectively, in 1993 and 1994. Cucumber, tomato, cabbage, potato, pepper, pea, and sweet corn were planted each spring, both 1 and 2 yr following the herbicide application. Cabbage was very sensitive and showed visible injury symptoms and yield reductions both years following flumetsulam plus clopyralid application. Pepper showed a yield reduction only in 1995. All other crops showed no injury or yield reductions. Flumetsulam plus clopyralid was applied PRE and postemergence (POST) to six sweet corn cultivars in 1995. These six sweet corn cultivars were replanted into the same site 1 yr later. Flumetsulam plus clopyralid severely injured three of six sweet corn cultivars in 1995, the year of application. Soil residues 1 yr later, however, did not injure or reduce yield of any sweet corn cultivars, including cultivars sensitive to ALS-inhibiting herbicides.

‘Ransom’, ‘Govan’, and ‘Bragg’ soybeans [Glycine max (L.) Merr.] were seeded in 30-, 61-, and 91-cm row spacings to achieve a uniform population of 323 000 plants/ha. In 1979 and 1980, shade development within the row was similar for all row spacings, but 15 cm from the row the inflection point occurred earlier when soybeans were seeded at the 30-cm row spacing. In 1979, shading 30 cm from the row was similar with the 61- and 91-cm row spacings, but in 1980 the 61-cm row spacing provided earlier shading. Shading within the row and 15 and 30 cm from the row was similar for all cultivars in 1979, but Govan and Bragg shaded row middles earlier than Ransom at the 91-cm row spacing. In 1980, shade development in the row was similar for all cultivars, but delayed shading was observed between the rows with Ransom. In 1979, maximum soybean seed yields were produced with 2, 2, and 0 weed-free weeks at the 30-, 61-, and 91-cm row spacings, respectively. In 1980, 2 weed-free weeks prevented soybean seed yield reductions at all row spacings. In 1979, Ransom, Bragg, and Govan required 4, 2, and 0 weed-free weeks, respectively, for maximum seed yields. In 1980, all cultivars achieved maximum seed yields with 2 weed-free weeks.

The phytotoxicity of postemergence propanil (3′,4′-dichloropropionanilide) to hard red spring (HRS) wheat (Triticum aestivum L.) was determined in the field and controlled environmental chamber. HRS wheat tolerance to propanil was influenced by cultivar, crop growth stage at time of application, and posttreatment temperature. Injury to wheat from propanil was greater at the five- than two-leaf stage of application and at 30- than at 10- or 20-C posttreatment temperatures. ‘Butte’ wheat was the most susceptible HRS wheat cultivar to propanil, with yield reductions ranging from 15 to 40% depending upon year and crop growth stage at application.

Soybean cultivars were grown in a hydroponic culture to evaluate tolerance to dimethenamid and metolachlor. Root length was reduced in 7 of the 32 cultivars with 50 ppb dimethenamid. ‘Asgrow 5403’ and ‘Bryan’ root lengths were reduced more than 20%. ‘Asgrow 6297’ was the only cultivar with greater than 12% root length reductions with 83 ppb metolachlor. The longest lateral root of all cultivars was shortened with dimethenamid. ‘NK-1460’ and Bryan expressed the most lateral root length reduction, at 73 and 62%, respectively. Asgrow 6297 was tolerant to dimethenamid, but lateral roots were reduced 16%. Metolachlor reduced the lateral root lengths of 12 cultivars, with Asgrow 5403, ‘Coker 6955,’ and Bryan reduced more than 20%. Bryan was the most sensitive cultivar to both herbicides, while ‘Brim’ was the most tolerant of cultivars evaluated.

Season-long weed control has been a goal of some producers of irrigated corn (Zea mays L.) to reduce competition, lessen weed seed production, facilitate crop harvest, improve water efficiency (particularly with furrow irrigation), and improve aesthetic properties of fields. Field experiments were conducted for 3 yr on sprinkler-irrigated corn on a loamy fine sand. Five herbicides applied at layby generally provided season-long control of grass weeds and reduced weed seed production up to 100%. Pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine] was particularly effective. Yields of irrigated corn were not increased by layby herbicide application. Use of corn rows spaced 91 cm apart and use of a shorter, early-maturing, horizontal-leaf corn cultivar resulted in greater weed growth and weed seed production than did use of 76-cm rows and a taller, full-season, upright-leaf corn cultivar. After nearly complete weed control with herbicides for 2 yr, withholding herbicide use in the third year allowed weed growth which reduced corn yield. Indications were that weed control efforts need to be continuous in irrigated corn production.

Experiments were conducted in the field, greenhouse, and controlled environmental chambers to determine the injury to sunflower (Helianthus annuus L.) from diclofop (2-[4-(2,4-dichlorophenoxy) phenoxy] propanoic acid} as influenced by diclofop rate, sunflower line and growth stage, and temperature/relative humidity (RH). Eighteen sunflower lines varied widely in response to diclofop applied postemergence at 2.2 kg/ha with visual injury ratings ranging from 5 to 46%. Neither diclofop-tolerant (Hybrids 894 and 903) nor diclofop-susceptible (Hybrid 923 and Inbred HA290) sunflower lines were injured by diclofop at 10 C. Diclofop injured all four sunflower lines at 30 C. Sunflower injury following diclofop application at 30 C was greater at 90% RH than at 40% RH; and the diclofop-susceptible lines were injured more than the diclofop-tolerant lines. Diclofop injury to sunflower at the two- to four-leaf stage was greater than at any other growth stage in the field and greenhouse. Seed yields of sunflower (Hybrid 894) treated with diclofop in the two- and four-leaf stage was reduced 15 and 12% compared to that of untreated weed-free sunflower, respectively, averaged over diclofop rates.

Field experiments were conducted in 1991 and 1992 to evaluate differential soybean cultivar tolerance to SAN 582H and metolachlor applied PRE, as influenced by soil moisture. Eighteen d after planting, a 3× rate of SAN 582H (3.0 kg ai ha−1) reduced plant populations of ‘Wright,’ ‘Bedford,’ and ‘Stonewall’ and metolachlor did not. At leaf drop, neither herbicide reduced crop height with optimum moisture. With excessive moisture, 3× rates of SAN 582H reduced plant height of Wright, Bedford, ‘Walters,’ ‘Young,’ ‘Brim,’ and ‘Bryan,’ and metolachlor reduced height of ‘Sharkey.’ The greatest yield reductions were due to excessive moisture, regardless of herbicide. Neither herbicide reduced yields with optimum moisture nor did a 1× rate with excessive moisture. However, with excessive moisture, a 3× rate of metolachlor (5.0 kg ai ha−1) reduced yield of Bedford by 470 kg ha−1, and the 3× rate of SAN 582H reduced yield of ‘Rhodes,’ Walters, and ‘Centennial’ more than 500 kg ha−1. Overall, soybean tolerance to both herbicides was good, but if used above recommended rates and with excessive moisture, injury can occur.

Field studies were conducted in 1999 and 2000 at Marianna and Gainesville, FL, to evaluate the response of three runner-type peanut cultivars, ‘Georgia Green’, ‘C-99R’, and ‘MDR-98’, to flumioxazin applied preemergence at 0, 71, 105, and 211 g/ha in a weed-free environment. Peanut exhibited excellent tolerance to flumioxazin, regardless of flumioxazin rate or peanut cultivar, at Gainesville in 1999 and both locations in 2000. In 1999, at Marianna, flumioxazin caused early-season stunting and season-long reduction in peanut canopy width. Peanut response was independent of cultivar and did not exceed 25%, with an increase in stunting with higher flumioxazin rates. Peanut stunting was associated with cool and extremely wet growing conditions during the first 2 mo after planting in 1999 at Marianna. Peanut yield and grade parameters, in both years, were not affected by flumioxazin treatment.