CHEMICAL FALLOW CONTROL OF NUTSEDGE

Summary. Field experiments were conducted to find a herbicide for complete control of nutsedge ( Cyperus rotundus L.). We applied seventeen herbicides and some of their combinations as chemical fallow. EPTC and CP-31675 (6- tert -butyl-2-chloro-o-acetotoluidide) gave good but only temporary control of nutsedge. Dichlobenil at 2·5 or 5 lb/ac gave fair control for 1 year. Rates of 10 or 20 lb/ac of dichlobenil controlled nutsedge completely for 1 year but severely reduced the yield of oats planted 5 months after application. The highest rate completely killed tubers and prevented reinfestation for 1 year. Analyses indicated no residue of dichlobenil or of its metabolite, 2,6-dichlorobenzoic acid, in vegetative parts and seeds of oats planted 5 months after application of 2.5, 5 or 10 lb/ac of dichlobenil. At equivalent rates the herbicide TH-073-H (N-hydroxymethyl-2,6-dichlorothiolbenzamide) gave control of nutsedge similar to that with dichlobenil. The combinations of 8 lb/ac amitrole-T and 10 lb/ac dichlobenil or TH-073-H were just as effective in controlling nutsedge shoots and tubers as dichlobenil or TH-073-H applied alone. The mixture of dichlobenil plus CP-31675, each at 5 lb/ac, gave excellent control of nutsedge and tubers for 1 year. The herbicides terbacil ( 3-ter -Nbutyl-5-chloro-6-methyluracil) or Du Pont 733 ( 3-tert -butyl-5-bromo-6-methyluracil) at 10 lb/ac provided almost complete control of nutsedge. Application of terbacil to plants aged 4–6 weeks gave better results than application to mature nutsedge in the fall.
La lutte chimique contre le cypirus     

A national survey of the occurrence of infectious bovine keratoconjunctivitis

SUMMARY A national mail survey of 4880 beef and dairy producers was undertaken to record details of infectious bovine keratoconjunctivitis. One thousand four hundred and fifty eight (29.8%) questionnaires were returned. The survey confirmed the widespread nature of the disease with higher prevalence in the summer months, in calves and dairy cattle, and in Bos taurus breeds. The constant prevalence contrasts with the disease in New Zealand where it is increasing.     

Prevalence of reoviruses in commercial chickens

The prevalence of reoviruses in commercial chickens with the runting/stunting syndrome, tenosynovitis, and normal chickens was investigated. Reoviruses were isolated from 3-week-old chickens affected with the runting/stunting syndrome and from older chickens with tenosynovitis; viruses were isolated from tissues with and without lesions. Reoviruses were also frequently isolated from rectal contents of normal 3-week-old chickens, and there was serological evidence of previous reovirus infection in all flocks of adult meat breeder chickens examined. The widespread occurrence of reoviruses in both normal and diseased chickens indicates that the isolation of reoviruses from tissues of chickens with lesions does not necessarily imply any aetiological relationship of reovirus with disease, even in the absence of other known causes. However, the occurrence of reovirus in normal chickens does not preclude an aetiological relationship with disease and further investigation of strain variation and possible virulence factors in avian reoviruses is required.     

The release of insoluble antibiotics from collagen ocular inserts in vitro and their insertion into the conjunctival sac of cattle

The release rate of procaine penicillin, erythromycin and erythromycin estolate from soluble and insoluble collagen films was investigated in vitro to develop an ocular insert for the treatment of infectious bovine keratoconjunctivitis. The release rate and duration of release varied according to the selection of antibiotic and vehicle. The combination of erythromycin estolate and soluble collagen produced the most sustained drug-delivery system. However, due to the inappropriate physical properties of collagen and poor retention of ocular inserts, it was considered that the development of an antibiotic-impregnated collagen ocular insert requires further investigation.     

Public Education Financing Trends and the Gray Peril Hypothesis

The effects of migrating seniors on the provision of local public services in rural communities is growing in importance because of the large number of retiring baby boomers and the increasing rate at which these retirees are locating outside traditional retirement destinations. Some communities are optimistic about attracting and retaining retirees as an economic development strategy, but others are concerned that inmigrating seniors may be reluctant to support local public services, such as education, bringing with them “Gray Peril.” This article attempts to clarify questions regarding the Gray Peril hypothesis and local ability and willingness to fund education in Tennessee, an increasingly popular retirement destination. To this end, county per pupil education expenditure growth is explained by growth trends in local property tax assessment and sales tax revenue, and migration patterns of the retirement‐aged population from 1962 to 2002.     

Labor Environment and the Location of Electrical Machinery Employment in the US. South

This study focuses on the location of electrical machinery manufacturing in South Carolina, Georgia, Mississippi, and Alabama (with special attention given to the first three states), and the degree to which this industry is associated with labor environments attractive to firms in the late stage of the product cycle. Labor-environment variables were selected from published sources and then collapsed into principal components. County-level component scores were then correlated with selected electrical machinery employment variables. The analysis suggests that, with the possible exception of electronic components manufacturing, there has been no widespread locational response by electrical machinery manufacturing in these states to labor environments attractive to firms in the late stage of the product cycle.