Field studies conducted in 1990 and 1991 at five locations in Georgia and one location in Virginia in 1991 evaluated imazethapyr [2-[4,5-dihydro-4-methyl-4-( l-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-ethyl-3-py~idinecarboxylic acid] and AC 263,222 [(+)-2[4,5-dihydro-4-methyl-4-( ~-methylethyl)-5-oxo-~H-imidazol-2yl]-5-methyl-3-pyridinecarboxylic acid] for weed control, peanut tolerance, and yield. Imazethapyr and AC 263,222 applied early postemergence (EPOST) controlled smallflower morningglory Vacquemontia tamnqolia (L.) Griseb], fpomuea morningglory species, prickly sida (Sida spinosa L.), and coffee senna (Cassia occidentalis L.) greater than 90%. Imazethapyr did not control Florida begganveed [Desmodium tortuosum (SW.) DC.] or sicklepod (Cassia obtusijoolia L.) adequately, with control generally less than 40%. AC 263,222 controlled Florida begganveed greater than 92% when applied EPOST and from 54 to 100% when applied postemergence (POST). Imazethapyr applied preplant incorporated (PPI) controlled bristly starbur (Acanthospermum hispidium DC.) 89% and imazethapyr and AC 263,222 applied EPOST controlled at least 96%. Imazethapyr controlled yellow nutsedge (Cyperus esculentus L.) 83% when applied PPI and 93% as an EPOST application. AC 263,222 controlled yellow nutsedge at least 90%. Peanut yields were higher with AC 263,222 than with imazethapyr. Imazethapyr systems that included alachlor (2-chloro-N-(2,6-ðylphenyl)-N-(methoxymethyl)acetamide), lactofen ([ (+)Z-ethoxy-l-methylz o x o e thy1 5 -[ 2-chlo ro-4-( t ri fluo rom e thy1)p he noxy ] -2nitrobenzoate] + 2,4-D B [4-(2,4-dichlorophenoxy)butanoic acid], paraquat [ 1, 11-dimethyl-4,4'-bipyridinium ion] + 2,4-DB, pyridate [~-(6-chloro-3-phenyl-4-pyridazinyl)-~-octyl carbonothioate] + 2,4-DB, metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-l-methylethyl)acetamide], or 2,4-DB provided yields equivalent to AC 263,222.

The projected expansion of SUAS operations in the U.S. has motivated the examination into how these aircraft will "see and be seen" by other aircraft operating in the U.S. National Airspace System (NAS). One proposal is that the SUAS use a system compatible with aviation, such as the Automatic Dependent Surveillance -Broadcast (ADS-B) surveillance service. This analysis intends to highlight the impact on the Universal Access Transceiver (UAT) ADS-B system performance from a shared-use operation by SUAS. The purpose is to examine various operational scenarios and estimate UAT's ability to continue to support existing air traffic management air-to-air and air-to-ground applications. The study extended prior research and examined a multitude of scenarios from low to high stress cases. The analysis indicates the key parameters are SUAS ADS-B transmission power and SUAS traffic density. These two parameters can be balanced to attain an acceptable demand on the UAT in areas of potentially high SUAS concentration while still providing safety and utility to all aircraft.

Adult horn fly, Haematobia irritans (L.), survival, mating success, and ovarian development were measured following exposure of pupae to 4 degrees C for 2, 3, and 4 wk, and were compared with an untreated control group held at 29 degrees C. Survival varied inversely with duration of low-temperature exposure, and ranged from 92.1% in the control to 7.0% following a 4-wk exposure. Mating success also varied inversely with duration of low-temperature exposure, and ovarian development was delayed, especially in the week 4 group. Reproductive and population parameters were measured in a 2nd cohort of horn flies following exposure of pupae to 1-4 wk at 4 degrees C, and in a control. Adult longevity varied inversely with duration of exposure. Mean longevity was greatest in the week 1 group at 17.6 d, followed by the control at 14.7 d. Week 4 flies lived an average of 2.2 d and produced no eggs. The preoviposition period was longest in the week 3 group at 7.3 d. In cohort 2, control and week 1 flies produced the highest number of eggs, eggs per female, and eggs per day compared with other groups. Eggs were produced over a mean of 6.8 d by week 3 flies compared with 25.4 d by week 1 flies. Reproductive rates varied inversely with low-temperature exposure duration, as did F1 generation egg hatch, larval development, and adult emergence. Survivorship and fecundity schedules are discussed with respect to the effects of low-temperature exposure duration. The effects of low-temperature exposure duration on horn fly reproduction and life-history patterns are discussed with respect to rearing, storage, and ecology.

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