With the increase in hectares planted to auxin-resistant cotton, the number of preplant, at-plant, and postplant applications of dicamba and 2,4-D choline to aid in the control of troublesome broadleaf weeds, including glyphosate-resistant Palmer amaranth, has increased. More dicamba and 2,4-D choline applications mean an increased risk of off-target movement. Field studies were conducted in 2019 to 2021 at the Texas Tech University New Deal Research Farm to evaluate dicamba-resistant cotton response to various rates of 2,4-D choline when applied at four growth stages (first square [FS] + 2 wk, first bloom [FB], FB + 2 wk, and FB + 4 wk). Applications of 2,4-D choline were applied at 1,060 (1X), 106 (1/10X), 21 (1/50X), 10.6 (1/100X), 2.1 (1/500X), and 1.06 (1/1000X) g ae ha−1 to Deltapine 1822 XF cotton. Relative to the nontreated control, yield losses were observed in all years at FS + 2 wk and FB from rates of 2,4-D choline ≥ 1/100X. At the FB + 4 wk application, only the 1X rate of 2,4-D choline resulted in a yield reduction in all three years. Micronaire, fiber length, and uniformity were negatively influenced by the 1/10X and 1X rates of 2,4-D choline at various timings in 2019, 2020, and 2021. In addition, short fiber content, neps, and seed coat neps increased where micronaire, fiber length, and uniformity were negatively impacted.

To improve the efficiency of isolating and culturing lichen mycobionts, we performed a growth assay on an Australian strain of the soil-crust lichenized fungus Endocarpon pusillum Hedw. This assay determined the preferred nitrogen and carbon sources of the fungus by limiting the available nitrogen or carbon sources to single compounds found in soils, plants and lichen thalli. We found that the non-proteinaceous amino acid, GABA, produced the most growth of all nutrients when provided as the sole nitrogen source but was a poor carbon source. Fructose, glucose, cellobiose and sorbitol produced the most growth of all the carbon sources tested. Ammonium, nitrate and polyamines were poor nutrient sources. These findings correspond with reports of primary metabolite pools in other lichen species and may guide future studies involving growth of recalcitrant lichen mycobionts.

Since the release of dicamba-tolerant cotton in 2016, preplant and POST applications of dicamba to control glyphosate-resistant Palmer amaranth have increased. With the increase in area treated with dicamba, the risk of off-target movement to nontarget crops has increased. A field study was conducted at the Texas Tech University New Deal Research Farm equipped with subsurface drip irrigation in 2017 and 2018 to evaluate non-dicamba tolerant cotton response to dicamba when applied at four crop growth stages [first square (FS) + 2 wk, first bloom (FB), FB + 2 wk, and FB + 5 wk]. Dicamba at 0.56 (1×), 0.056 (1/10×), 0.0112 (1/50×), 0.0056 (1/100×), and 0.00112 (1/500×) kg ae ha−1 was applied to ‘FM 1830GLT’ cotton. When applications were made at FS + 2 wk, a shift in boll nodal position was apparent following dicamba at the 1/50× rate in 2017 and at 1/10× in 2018 compared to the nontreated control (NTC). A shift in boll distribution from the 1/50× rate of dicamba was apparent at FB in 2017, but not in 2018. Dicamba applied at the 1× rate at FB + 2 wk resulted in reduced boll numbers. No change in boll number or boll position was apparent following any dicamba rate when applied at FB + 5 wk in both years. Dicamba applied at 1/500×, 1/100×, and 1/50× rates at all timings did not affect yield relative to the NTC. When dicamba was applied at the 1/10× rate, the greatest yield loss was observed at FS + 2 wk followed by FB and FB + 2 wk. Micronaire increased following dicamba applied at 1/10× at FS + 2 wk, FB, and FB + 2 wk in 2017. In 2018, micronaire decreased following dicamba applied at 1/10× at FB + 5 wk.

A wide margin of crop safety is a desirable trait of POST herbicides, and investigation of crop tolerance is a key step in evaluation of new herbicides. Six field experiments were conducted in Ontario, Canada, from 2017 to 2018 to examine the influence of corn (Zea mays L.) hybrid (DKC42-60RIB, DKC43-47RIB, P0094AM, and P9840AM), application rate (1X and 2X), and application timing (PRE, V1, V3, and V5) on the tolerance of field corn to tolpyralate, a new 4-hydroxyphenyl pyruvate dioxygenase inhibitor, co-applied with atrazine. Two corn hybrids (DKC42-60RIB and DKC43-47RIB) exhibited slightly greater visible injury from tolpyralate + atrazine, applied POST, than P0094AM and P9840AM at 1 to 2 wk after application (WAA); hybrids responded similarly with respect to height, grain moisture, and yield. Applications of tolpyralate + atrazine at a 2X rate (80 + 2,000 g ai ha−1) induced greater injury (≤31.6%) than the field rate (40 + 1,000 g ha−1) (≤11.6%); the 2X rate applied at V1 or V3 decreased corn height and slightly increased grain moisture at harvest. On average, field rates resulted in marginally higher grain yields than 2X rates. Based on mixed-model multiple stepwise regression analysis, the air temperature at application, time of day, temperature range in the 24 h before application, and precipitation following application were useful predictor variables in estimating crop injury with tolpyralate + atrazine; however, additional environmental variables also affected crop injury. These results demonstrate the margin of corn tolerance with tolpyralate + atrazine, which provides a basis for optimization of application timing, rate, and corn hybrid selection to mitigate the risk of crop injury with this herbicide tank mixture.

Herbicide-resistant weeds are a growing concern globally; in response, new herbicide resistance traits are being inserted into crops. Isoxaflutole-resistant soybean [Glycine max (L.) Merr.] will provide a new mode of action for use in this crop. Ten experiments were conducted over a 2-yr period (2017, 2018) to determine herbicide interactions between isoxaflutole and metribuzin on soybean injury, weed control efficacy, and soybean yield on a range of soil types. Soybean leaf-bleaching injury caused by isoxaflutole was most severe at sites with higher levels of rainfall after application. Control of weed species with isoxaflutole (52.5, 79, and 105 g ai ha−1) and metribuzin (210, 315, and 420 g ai ha−1) differed by site based on amount of rainfall after application. At sites where there was sufficient rainfall for herbicide activation, isoxaflutole at all rates controlled common lambsquarters (Chenopodium album L.), Amaranthus spp., common ragweed (Ambrosia artemisiifolia L.), and velvetleaf (Abutilon theophrasti Medik.) >90%; metribuzin at all rates controlled Amaranthus spp. and witchgrass (Panicum capillare L.) >80%. Control of every weed species evaluated was reduced when there was limited rainfall after herbicide application. The co-application of isoxaflutole + metribuzin resulted in additive or synergistic interactions for the control of C. album, Amaranthus spp., A. artemisiifolia, A. theophrasti, Setaria spp., barnyardgrass [Echinochloa crus-galli (L.) P. Beauv], and P. capillare. Isoxaflutole and metribuzin can be an effective management strategy for common annual broadleaf and grass weeds in Ontario if timely rainfall events occur after herbicide application.

Transgenic crops are being developed with herbicide resistance traits to expand innovative weed management solutions for crop producers. Soybean with traits that confer resistance to the hydroxyphenylpyruvate dioxygenase herbicide isoxaflutole is under development and will provide a novel herbicide mode of action for weed management in soybean. Ten field experiments were conducted over 2 years (2017 and 2018) on five soil textures with isoxaflutole-resistant soybean to evaluate annual weed control using one- and two-pass herbicide programs. The one-pass weed control programs included isoxaflutole plus metribuzin, applied PRE, at a low rate (52.5 + 210 g ai ha−1), medium rate (79 + 316 g ai ha−1), and high rate (105 + 420 g ai ha−1); and glyphosate applied early postemergence (EPOST) or late postemergence (LPOST). The two-pass weed control programs included isoxaflutole plus metribuzin, applied PRE, followed by glyphosate applied LPOST, and glyphosate applied EPOST followed by LPOST. At 4 weeks after the LPOST application, control of common lambsquarters, pigweed species, common ragweed, and velvetleaf was variable at 25% to 69%, 49% to 86%, and 71% to 95% at the low, medium, and high rates of isoxaflutole plus metribuzin, respectively. Isoxaflutole plus metribuzin at the low, medium, and high rates controlled grass species evaluated (i.e., barnyardgrass, foxtail, crabgrass, and witchgrass) 85% to 97%, 75% to 99%, and 86% to 100%, respectively. All two-pass weed management programs provided 98% to 100% control of all species. Weed control improved as the rate of isoxaflutole plus metribuzin increased. Two-pass programs provided excellent, full-season annual grass and broadleaf weed control in isoxaflutole-resistant soybean.

Dicamba may be an efficacious option for the control of glyphosate-resistant (GR) horseweed in glyphosate/dicamba-resistant soybean; research is needed to optimize the application rate based on horseweed height at the time of application. The purpose of this study was to determine the effect of glyphosate/dicamba rate and application timing for the control of GR horseweed. Glyphosate/dicamba was applied at three rates (900, 1,350, and 1,800 g ae ha−1) at three horseweed application timings (5, 15, and 25 cm) in a factorial design. There was no interaction between glyphosate/dicamba rate and timing for GR horseweed control or soybean yield; however, there was an interaction for GR horseweed density and biomass. At 2 and 4 wk after application (WAA), there was a decrease in GR horseweed control as the height at the time application increased. At 4 WAA, the application of glyphosate/dicamba to GR horseweed that was 5-, 15-, and 25-cm tall provided 87%, 76%, and 62% control, respectively. There was no impact of glyphosate/dicamba application timing on soybean yield. At 2, 4, and 8 WAA, there was an increase in GR horseweed control as the rate of glyphosate/dicamba was increased. At 8 WAA, glyphosate/dicamba applied at 900, 1,350, and 1,800 g ae ha−1 controlled GR horseweed 76%, 87%, and 92%, respectively. Earlier application timings and higher rates of glyphosate/dicamba caused the greatest reduction in GR horseweed density and biomass. Reduced GR horseweed competition resulted in a 100% to 144% increase in soybean yield, but there was no difference in soybean yield among glyphosate/dicamba rates tested.

Control of broadleaf weeds in caladium is difficult due in part to a lack of selective POST herbicides. Cultivation is not an option due to the dense canopy and potential for tuber injury. As a result, growers currently rely on preemergence (PRE) herbicide and hand-weeding. The objective of this research was to evaluate the control of four common broadleaf weeds of field grown caladium with POST applications of halosulfuron, thifensulfuron-methyl, and trifloxysulfuron, and determine the tolerance of caladium cultivars ‘Florida Fantasy’ and ‘Florida cardinal’ to POST applications of halosulfuron. At 4 weeks after treatment (WAT), thifensufluron-methyl at 28 g ai ha−1 and trifloxysulfuron at 84 g ai ha−1 provided approximately 90 and 70% common purslane control, respectively, while halosulfuron at 210 g ai ha−1 provided 55% suppression. Trifloxysulfuron controlled ≥90% spotted spurge at 42 g ha−1, whereas the highest rate of halosulfuron and thifensulfuron-methyl only achieved 60% suppression. In field experiments, the evaluated sulfonylurea (SU) herbicides were less efficacious on hairy indigo and sharppod morningglory as control never exceeded 65 and 50%, respectively. In greenhouse experiments, the evaluated halosulfuron rates ranging from 26 to 420 g ha−1 did not significantly reduce caladium tuber weight from the nontreated control. Averaged over halosulfuron rates, ‘Florida Fantasy’ damage was 5 and 6% at 2 and 4 WAT, respectively, while ‘Florida Cardinal’ damage was 11%. We conclude that none of the herbicide treatments effectively controlled all species evaluated. Sequential treatments, higher rates, or tank-mixtures may be necessary to adequately control these species. We also conclude that caladium cultivars ‘Florida Fantasy’ and ‘Florida Cardinal’ have acceptable tolerance to POST applications of halosulfuron. Further research is needed to evaluate caladium tolerance to other SU herbicides.

A population level, two-compartment, temperaturedependent model that predicts date of seedling johnsongrass flowering was formulated. The model consisted of a fourparameter poikilotherm rate equation to describe development rate as a function of temperature and a temperature-independent Weibull function to distribute flowering times for the population. Experiments were conducted to determine the effect of temperature, nitrogen availability, and water availability on development of seedling johnsongrass. Development was most sensitive to temperature while the effect of nitrogen concentration and water availability was minimum and inconsistent. The model was tested against three independent field data sets and provided accurate prediction of flowering dates for each data set.

MKH 6562 is a new acetolactate synthase inhibitor herbicide that would provide an alternative to control wild oat. Three experiments were conducted at Scott, SK, Canada, from 1996 to 1999 to evaluate MKH 6562 rates (20 and 30 g ai/ha), carrier volumes (30, 50, and 100 L/ha), time of applications (two- to three-leaf and three- to four-leaf stages of wild oat), and broadleaf weed herbicide tank mixtures. Reduced wild oat control (lower visual rating of percent control and higher fresh weight) often occurred when MKH 6562 was applied at a rate of 20 vs. 30 g/ha, with carrier volumes of 30 vs. 50 and 100 L/ha, and at the three- to four-leaf vs. two- to three-leaf stages of wild oat. Wild oat control generally was lower for MKH 6562 tank mixed with dicamba + mecoprop + MCPA 1:1:4.4 and bromoxynil + MCPA 1:1 compared with MKH 6562 applied alone or tank mixed with other broadleaf herbicides. MKH 6562 tank mixed with MCPA, and to a lesser extent 2,4-D, resulted in decreased wild oat control when applied at the three- to four-leaf stage of wild oat, but not at the two- to three-leaf stage. Wheat grain yield usually was not affected by MKH 6562 rate and carrier volume. Yield was 7% lower when MKH 6562 was tank mixed with dicamba + mecoprop + MCPA or fluroxypyr + 2,4-D and was 8% lower when MKH 6562 was applied in a mixture with 2,4-D formulations or bromoxynil + MCPA at the three- to four-leaf stage compared with the two- to three-leaf stage. Similar yields were achieved when MKH 6562 was applied alone at both leaf stages of wild oat. Wild oat control and wheat yield with MKH 6562 were as good as or better than with ICIA 0604 and imazamethabenz and were as good as or poorer than with CGA 184927. MKH 6562 provides adequate control of wild oat in wheat when applied early with the recommended carrier volume. Satisfactory control may be achieved with reduced rates if wild oat infestations are light.

An experiment was conducted at two locations in 2003 and 2004 to determine the timing and rate of thifensulfuron that is safe to use on sweetpotato. Thifensulfuron was applied 1, 2, and 4 wk after transplanting (WAP) in 2003 and 4, 6, and 8 WAP in 2004. Within each timing, thifensulfuron treatments were 1.1, 2.1, 3.2, 4.3, and 8.5 g ai/ha plus a weed-free control. The 1 and 2 WAP timings of thifensulfuron reduced the yield of number 1 roots greater than 25%. The 4, 6, and 8 WAP timings had less than 15% reduction in yield, with the 6 WAP timing reducing number 1 roots and total yield 10% or less. When 4.3 g/ha of thifensulfuron was applied 4 WAP, total yield was reduced 13%. The 6 and 8 WAP timings had little yield reduction, with no rate response observed. Application of 4.3 g/ha of thifensulfuron at 6 WAP would allow for control of problematic weed species while limiting potential yield loss. Yield loss from a 4 WAP application of thifensulfuron may in fact be a delay in crop maturity that could be recovered if the sweetpotato harvest was delayed to allow for the optimal amount of number 1 grade roots to be produced.

Field studies were conducted to determine the effect of halosulfuron at 0, 13, 26, 39 or 52 g ha−1 applied 10, 22, and 31 d after planting (DAP) on ‘Beauregard' and ‘Covington' sweetpotato. Storage roots were harvested, graded, cured, and stored in controlled environment for 2 mo. Where injury on storage roots was observed, external injury occurred on the surface of the storage root as a blackened area with blistering and internal injury consisted of small red-brown spots inside the sweetpotato storage root. Total yield of sweetpotato with 13 g ha−1 halosulfuron treatment (155,157 kg ha−1) was similar to the nontreated check (162,002 kg ha−1). However, halosulfuron rates above 13 g ha−1 resulted in a reduction of marketable grade roots and total yield of sweetpotato. Regardless of rate and timing of halosulfuron, external and internal injury to Beauregard storage roots was less than 6 and 9%, respectively. No external injury to Covington was observed from all rates of halosulfuron applied POST at 10 DAP. Halosulfuron at 22 DAP to Covington caused greater external injury to storage roots than was observed on the nontreated. Thus, Beauregard appears more tolerant to halosulfuron POST than Covington. To minimize internal or external injury to storage roots of Covington, halosulfuron must be applied within 10 DAP.

Studies were conducted in 2003 and 2004 to determine the effect of application timing and halosulfuron rate on sweetpotato yield and quality. Halosulfuron was applied 1, 2, and 4 wks after transplanting (WAP) sweetpotato in 2003, and 2, 3, and 4 WAP in 2004. Treatments within each timing included halosulfuron at 13, 26, 39, 52, and 65 g ai/ha plus a weed-free control. Combined over year, site, cultivar and rate, halosulfuron applied at 1, 2, 3, and 4 WAP stunted sweetpotato 32, 15, 11, and 14%, respectively, rated 2 wks after treatment. The stunting observed with the 1 and 2 WAP timings caused a 17 and 10% reduction in yield of No. 1 roots, respectively, compared with the weed-free control. The 3 and 4 WAP timings of halosulfuron did not reduce yield of No. 1 roots. Total yield was reduced approximately 11% at the 1, 2, and 3 WAP application timings. Halosulfuron at 4 WAP did not reduce total yield. Combined over year, site, and cultivar, halosulfuron applied at 39 g/ha did not reduce the weight of No. 1 roots or total crop yield and thus could be an effective POST option for weed control in sweetpotato.

Background: Old age psychiatry as a clinical specialty emerged in the 1970s and modern, open-access multidisciplinary services started in the mid-1980s in South London. There are few accounts of referrals to old age psychiatry services and no quantitative accounts of the referral patterns to such teams. We report on the first 10,000 patients newly referred to the first such service in the world.

Methods: Observational study on routinely gathered data on age, gender, referral source, discipline of team member involved, diagnosis and duration of contact. Data validation was by iterative feedback to clinicians.

Results: Ten thousand patients were referred between December 1983 and March 2000. Missing data rates were low. The overall referral rate was 21.0 per 1000 population over 65 per annum, with the highest rate in those 85+ years old, in whom there was a marked rise over time. The rise in referral rate compensated for a decline in the population over 65 so that the numbers of referrals rose. Although there was a rise in the rate of referral of people with an organic diagnosis over time, this was not statistically significant. Organic patients constituted 50–60% of referrals but had shorter contact times than functional ones. Cause for concern included a low rate of referral from care homes, and a high proportion of possibly inappropriate referrals from medical and general psychiatry services. We were pleased to see no excess of such referrals from open-access sources, confirming earlier work.

Conclusions: Descriptive data on referrals and workload of the first open-access multidisciplinary old age psychiatry service have generated cause for both celebration and concern.

We consider the problem of scheduling n jobs non-preemptively on m parallel, non-identical processors to minimize a weighted expected cost function of job completion times, where the weights are associated with the jobs. The cost function is assumed to be increasing and concave but otherwise arbitrary. Processing times are IFR with different distributions for different processors. Jobs may be processed on any processor and there are no precedences. We show that the optimal policy orders the jobs in decreasing order of their weights and then uses the individually optimal policy for each job. In other words, processors are offered to jobs in order, and each job considers its own expected cost function for its completion time to decide whether to accept or reject a processor. Therefore, the optimal policy does not depend on the weights of the jobs except through their order. Special cases of our objective function are weighted expected flowtime, weighted discounted expected flowtime, and weighted expected number of tardy jobs.