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Production of birdsfoot trefoil (Lotus corniculatus L.) is limited in humid, temperate regions by foliar and shoot blight caused by Rhizoctonia species. The objective of this study was to develop methods for quantifying blight symptoms on 14 plant introductions and three cultivars of birdsfoot trefoil. Susceptibility was evaluated in the greenhouse on the basis of shoot lesion formation and blight of leaves and apical meristems. On the basis of these symptoms, no entry of this limited collection of birdsfoot trefoil was completely resistant to infection. However, 4 d after inoculation, shoot lesion length differed significantly among entries. Additionally, lesion lengths varied between experiments in relation to environmental conditions. In contrast to shoot lesion length, foliar blight and the time to blight of apical meristems did not vary significantly among entries in either experiment. Shoot lesion development limits foliage production and survival under field conditions and should be considered an important factor in further screening of birdsfoot trefoil for disease resistance., BIRDSFOOT TREFOIL is a perennial legume that is important in forage systems in the USA. In northern regions, stands of birdsfoot trefoil will occasionally re-seed, replacing plants lost to a [...]

The population dynamics of perennial crop plants are influenced by numerous factors, including management practices. Conditions in the field vary from year to year, and matrix population models are useful for evaluating population behaviour in relation to environmental variability. In Missouri, the stand persistence of birdsfoot trefoil (Lotus corniculatus), a perennial legume, is often limited by disease and poor seed production. A stage-based matrix population model was developed to evaluate the population dynamics of birdsfoot trefoil in relation to clipping treatment. The plant growth stages represented in the model were seeds, seedlings, mature vegetative and reproductive plants. Two phases of population growth were evaluated in clipped and unclipped stands. Establishment-phase populations were characterized by relatively high mortality and low reproduction. Elasticity analysis indicated that growth of these populations was most sensitive to the survival of vegetative plants. Mature vegetative plants and seeds comprised the majority of surviving individuals in clipped and unclipped populations, respectively; however, establishment-phase populations under both management treatments tended toward extinction. Populations in the post-establishment phase of growth were characterized by relatively low mortality and high reproduction. Population growth in this phase of growth was most sensitive to seed production, and most individuals in these populations were at the seed stage. [ABSTRACT FROM AUTHOR]

The article presents a study on diplodia corticola caused stem and branch cankers on white oak in a farm in Missouri.

We used PCR to differentiate species in the genus Phytophthora, which contains a group of devastating plant pathogenic fungi. We focused on Phytophthora parasitica, a species that can infect solanaceous plants such as tomato, and on Phytophthora citrophthora, which is primarily a citrus pathogen. Oligonucleotide primers were derived from sequences of a 1,300-bp P. parasitica-specific DNA segment and of an 800-bp P. citrophthora-specific segment. Under optimal conditions, the primers developed for P. parasitica specifically amplified a 1,000-bp sequence of DNA from isolates of P. parasitica. Primers for P. citrophthora similarly and specifically amplified a 650-bp sequence of DNA from isolates of P. citrophthora. Detectable amplification of these specific DNA sequences required picogram quantities of chromosomal DNA. Neither pair of primers amplified these sequences with DNAs from other species of Phytophthora or from the related genus Pythium. DNAs from P. parasitica and P. citrophthora growing in infected tomato stem tissue were amplified as distinctly as DNAs from axenic cultures of each fungal species. This is the first report on PCR-driven amplification with Phytophthora species-specific primers.

Psychiatric units in general hospitals are exempt from diagnosis-related groups (DRGs), a system of per case prospective payment that is used for the majority of patients covered by Medicare. The American Psychiatric Association purchased a large hospital discharge data base and studied the potential impact of DRGs on psychiatric patients and inpatient psychiatric units in general hospitals. There was substantial inaccuracy in the psychiatric DRGs' prediction of resource use, which could lead to inappropriate discharge of patients and financial risk to hospitals that treat more severe cases. The authors advocate further research because psychiatry must anticipate prospective payment in the future.

The prospective payment system based on diagnostic related groups adopted by Medicare in 1983 has many deficiencies with respect to psychiatric care. Due to the efforts of the American Psychiatric Association, psychiatric units in general hospitals have been temporarily exempted from this system of per-care payment. A number of problematic issues need to be addressed in the design of any modified or alternative system of financing psychiatric care. These issues include the problems of premature discharge, code manipulation, cost-shifting, and equitable patient access to psychiatric services. The potential effects of a DRG system of payment on clinical practice are reviewed. The reasons for the shortcomings of the DRG system in predicting utilization of services are discussed, and areas for future research are suggested.

Training in community psychiatry is becoming an integral part of psychiatric residencies. This paper outlines the contribution to such training of Job Corps centers, serving as teaching laboratories in community psychiatry. As the only national training program for disadvantaged adolescents, Job Corps operates 123 centers across the country. Each center functions as a community in microcosm and provides an excellent opportunity for the learning and study of mental health consultation and social system dynamics. The Job Corps Mental Health Program provides a learning opportunity for psychiatrists at all levels of development.