Field experiments were conducted to determine the efficacy of fluazifop-P-butyl for the control of green foxtail, wild oat, barley, and wheat in flax as influenced by spray nozzle orientation, time of day, and growth stage. Under drought conditions in 1988, control of wild oat, wheat, and barley with fluazifop-P-butyl was enhanced 75%, 53% and 78%, respectively, when nozzles were oriented to spray forward 45°. Under adequate soil moisture conditions enhancement of control was minimal. Green foxtail control improved when fluazifop-P-butyl was applied from 1700 to 2100 h, but time of day had no effect on control of wild oat, barley, or wheat. Fluazifop-P-butyl effectiveness was reduced when applied 4 d after flax emergence due to late emerging grass seedlings. Green foxtail was the most tolerant to fluazifop-P-butyl, whereas wild oat, wheat, and barley were the most susceptible.

Velvetleaf plants have diurnal leaf movements, which may result in decreased interception of herbicides when applications are made near sunset. However, it is not known if leaf angle alone accounts for diurnal fluctuations in efficacy. Greenhouse experiments were conducted to determine the effect of time of day (TOD) of application and velvetleaf leaf angle on glufosinate efficacy and spray interception. Glufosinate at 90, 180, and 360 g ai/ha was applied to 10-cm-tall plants at 4:00, 6:00, 7:00, 7:30, and 8:00 P.M., respectively. Leaf angles were either manipulated physically to −90° or the plant's natural 2:00 P.M. leaf angle (approximately −10°) or were allowed to exhibit their natural leaf movements. Plant dry weight 3 wk after treatment revealed that TOD effects were observed for all leaf angle treatments after glufosinate application at 90 g/ha. At 180 g/ha glufosinate, there was no TOD effect for plants with 2 P.M. leaf angles, whereas there was a TOD effect for plants with −90° and natural leaf angles. At 360 g/ha glufosinate, biomass for the −90° leaf angle plants was similar to that for the natural and the 2:00 P.M. leaf angle plants when glufosinate was applied at 4:00 P.M. but was significantly different at or after 6:00 P.M. This suggests that at least 4 h of light is needed to provide optimum herbicide activity when spray interception is reduced as a result of leaf movements. Leaf angle decreased by as much as 70% from 4:00 to 8:00 P.M., which resulted in approximately 50% less spray interception at 8:00 P.M. than at 4:00 P.M. These data provide evidence that leaf angle plays a pivotal role in reducing glufosinate efficacy when applications are made near sundown. However, leaf angle is not the sole reason for reduced efficacy because TOD effects were observed at different leaf angles with 4 h of light, after an application of 360 g/ha glufosinate.

The effect of time of day (TOD) on the activity of six common POST herbicides was investigated in field trials from 2007 to 2009 at two locations in southwestern Ontario. Percentage weed control was assessed following application of bentazon, chlorimuron-ethyl, fomesafen, glyphosate, imazethapyr, or quizalofop-p-ethyl applied at 3-h intervals from 6:00 A.M. to midnight, when weeds averaged 15 cm tall. The effect of time of day varied with weed species, but weed control was generally reduced when herbicides were applied at 6:00 A.M., 9:00 P.M., and midnight. Herbicide activity on velvetleaf was most frequently reduced, especially for chlorimuron-ethyl, glyphosate, and imazethapyr. Control of common ragweed with glyphosate and imazethapyr was also affected by the timing of application, and pigweed species only showed an effect with glyphosate. Variation in temperature, relative humidity, and dew presence/absence at different times of the day, as well as morphological/physiological characteristics such as weed size at time of application and diurnal leaf movement in response to light intensity, may account for the variation in weed control at different times of the day. Significant soybean yield loss was not observed in this study, but may occur if herbicide efficacy is severely reduced by application at inappropriate times of day. These results provide valuable information for growers, and suggest that POST herbicides are most effective when applied midday, rather than in the early morning or late evening.

Field trials were conducted from 2005 to 2007 at two locations in southwestern Ontario to investigate how weed control in corn was affected by the time of day that herbicides were applied. Weed control following the application of six POST herbicides (atrazine, bromoxynil, dicamba/diflufenzopyr, glyphosate, glufosinate, and nicosulfuron) at 06:00, 09:00, 12:00, 15:00, 18:00, 21:00, and 24:00 h was assessed. For many weed species herbicide efficacy was reduced when applications were made at 06:00, 21:00, and 24:00 h. Velvetleaf was the most sensitive to the time of day effect, followed by common ragweed, common lambsquarters, and redroot pigweed. Annual grasses were not as sensitive to application timing; however, control of barnyardgrass and green foxtail was reduced in some environments at 06:00 h and after 21:00 h. Only in the most severe cases was the grain yield of corn reduced due to decreased weed control. Daily changes in air temperature, relative humidity, and light intensity that cause species-specific physiological changes may account for the variation in weed control throughout the day. The results of this research suggest that there is a strong species-specific influence of ambient air temperature, light intensity, and leaf orientation on the efficacy of POST herbicides. These results should aid growers in applying herbicides when they are most efficacious, thus reducing costs associated with reduced efficacy.

Fresh market spinach has one primary herbicide, cycloate, which does not control all weeds. Previous studies demonstrated that cycloate PRE followed by (fb) phenmedipham at the four-leaf spinach stage is a safe and effective treatment. However, this treatment is not useful for the main growing season of fresh spinach due to its short crop cycle and the 21-d preharvest interval requirement of phenmedipham. This study evaluates the potential to use the combination of cycloate PRE fb phenmedipham on two-leaf spinach. Greenhouse and field studies were conducted in 2014 using three spinach varieties with low (‘Nordic' and ‘Sardinia') and high (‘Regal') tolerance to phenmedipham. Greenhouse studies revealed that phenmedipham at 90 g ai ha−1 was safe to Regal when applied at the two-leaf stage. Sardinia was more susceptible to phenmedipham injury under high (310 W m−2) light conditions than low (258 W m−2) light conditions. Impact of time of day on phenmedipham safety was evaluated in the field: day-long exposure to high light intensity following morning applications vs. evening applications fb exposure to low light intensity. Injury estimations taken 3 d after treatment (DAT) were lower for evening than for morning applications. Nonetheless, injury 11 DAT and spinach yield evaluations found no differences between morning and evening applications. Subsequently, cycloate (1,700 g ha−1) PRE fb phenmedipham (90 and 180 g ha−1) applied in the evening at the two-leaf stage was evaluated. A reference treatment was cycloate PRE fb phenmedipham (270 g ha−1) at the four-leaf stage. Treatments with cycloate fb two-leaf phenmedipham at 90 and 180 g ha−1 were safe to spinach and improved weed control compared to cycloate alone. Cycloate fb 180 g ha−1 phenmedipham at the two-leaf stage reduced weed biomass by 88% compared to cycloate alone. This level of weed control was similar to the reference treatment. Results here show that phenmedipham applied at the two-leaf stage is safe to fresh market spinach and it has the potential to be used during most of the fresh spinach growing season.

Persons with mental diseases are admitted to acute care psychiatric units during the day and night. The distribution of diagnoses given to these patients according to time of day has not previously been studied. All referrals during one year to a 27-bed facility were studied using the computerized medical records. 998 patients were referred during the year, of whom 480 were female. 47% arrived within office hours, 41% in the evening and 12% during the night. In order of frequency, patients with psychotic disorders comprised 26%, narrowly followed by the affective disorders (25%), substance abuse disorders (17%), then personality disorders (13%) and crises and anxiety disorders (12%). There is a tendency towards patients with lower diagnostic ICD-numbers (especially psychotic and affective diagnoses) arriving earlier than the other diagnostic groups. The diurnal variations in diagnoses were otherwise small.

Women with personality disorders were almost thrice as frequent as males, whereas males with substance abuse were almost twice as frequent as females. Patients above 60 years of age with non-abuse related organic disorders were mainly males (26 versus 7).

Patients > 60 years of age (N = 57) had the following frequencies of admission through the 24 hour period: 54.4%, 36.8% and 8.8% (office hours, evening, night), whereas patients below 60 years of age (N = 941) had 46.7%, 41.0% and 12.3%, respectively.