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Variation of a representative range of Colletotrichum isolates from diseased coffee berries, sampled from various regions in Ethiopia, was studied using morphological and pathological criteria. Spore suspensions from 4-week-old cultures of five isolates were applied to 8-week old seedlings, grown from known susceptible coffee cultivars, by wrapping strips of absorbent cotton wool dipped in inoculum around the seedlings. Substrate utilization of citrate and tartrate was assessed in stationary liquid. Morphological characters and conidial size were recorded. Random amplification of genomic DNA was done by PCR using 10 base primers. The seedling hypocotyl test confirmed variation in aggressiveness between the various isolates while biochemical tests and cultural characters showed that this was related to the occurrence of both Colletotrichum gloeosporioides and Colletotrichum kahawae in the range of isolates tested. PCR showed similar trends in the nucleotide sequence and did not differentiate between the isolates. The study showed that both C. kahawae and C. gloeosporioides occur in diseased berries, probably as sequential colonizers of diseased tissues.

Monitoring in banana pest management is an important activity for commercial and/or smallholder banana production. It is required to detect the occurrence of newly introduced pest species, those which have previously been of minor importance, and for new variants which pose particular threats. Monitoring is important strategically in providing early warning of problems that may arise, and in some cases as a basis for pest management decisions within a cropping season. Information from monitoring can also serve public policy purposes, such as the need for eradication programmes and quarantine. These different facets of monitoring are illustrated with reference to selected banana pests: the fungal pathogens causing leaf spots ( Mycosphaerella spp.) and Panama disease ( Fusarium oxysporum f. sp. cubense ); parasitic nematodes (especially Radopholus similis ) and the banana weevil ( Cosmopolites sorditus ).

Objectives: Retinoic acid (RA) and benzoyl peroxide (BP) were studied, comparing their keratolytic efficacy and water barrier disruption to that of salicylic acid (SA), a well-established keratolytic, under similar conditions. Patients/Methods:Six volunteers were included in this blinded study. Eleven randomized test sites were marked on the volar forearms, containing sites for untreated skin at time zero, unoccluded, occlusion, and vehicle controls for 3 and 6 h, and each of BP, RA, and SA solutions for 3 and 6 h. At each time point, occlusion at 5 of the test sites was removed, and chromameter measurements were performed over 30 min. Each site then underwent 25 stratum corneum (SC) tape strippings. At 1, 5, and 30 min after the last stripping at each site, TEWL measurements were performed. Quantitative protein analysis of the SC from the tapes was then performed. Results and Conclusion: After 3 h, BP was significantly more effective in disrupting SC cohesion than SA and RA, indicating BP is a moderate keratolytic agent in addition to its antimicrobial properties. After 6 h, all three agents were similarly effective in keratolysis. Barrier disruption, as measured by TEWL, paralleled depth of SC removal. SA tended to exhibit the greatest keratolytic efficacy superficially, hence its clinical effectiveness in superficial conditions such as comedonal acne, whereas BP was more effective at deeper levels, complimenting its antimicrobial effects and enabling it to treat deeper, more inflammatory lesions. None of the agents significantly affected skin erythema. These techniques provide a robust and rapid assay for in vivo keratolytic demonstration.

The INRMP developed this turtle sign project for Bellows Air Force Station (AFS) as a part of its natural resource management goals and objectives to positively impact the use of Waimanalo Bay by green sea turtles. According to the INRMP, "the Turtle Sign Project was developed to describe the possible impacts to green sea turtles from fishing and encourage cooperation from local residents and visitors for fishing in alternative areas." The purpose of this paper is to refine the sign concept and develop a final plan of action.

A normal coordinate approach was used to generate crystallographic packing candidates of a multitorsional polyimide synthesized from 3,3`,4,4`-benzophenonetetracarboxylic acid (BTDA) and 2,2-dimethyl-1,3-(4-aminophenoxy) propane (DMDA) (PI-2). Candidates were obtained under conditions of fixed axial advance of 24.6 {Angstrom} per monomer, and imposed 2/1 helical or 1/0 translational symmetry, consistent with the observed WAXD meridional layer line spacing. The ability of combinatorially generated torsional states to adopt the desired geometry was examined. Necessary corrections to the conformational parameter equations have been made. The procedure described allowed crystallographic conformations satisfying explicit geometric and MM3 intramolecular energy criteria to be generated for a linear multitorsional polyimide prior to the application of crystallographic screening or refinement procedures. 20 refs., 7 figs., 1 tab.

Ramularia collo-cygni nom.nov. is introduced for Ophiocladium hordei , non Ramularia hordei , and described from Hordeum, Phalaris, Glyceria and Triticale. The history of the species and its relationships with species of Ramularia, Ophiocladium and Ovularia are discussed.

The history and spread of coffee rust, from its first detection in Sri Lanka to the latest developments in Central America, are discussed. The epidemiology of the disease has been a subject of controversy in the past, but during the last decade most of the questions concerning the mode of spore dispersal seem to have been answered. Although it is necessary to investigate further the influence of host physiology on some epidemiological factors, such as latency and sporulation, sufficient is now known of the epidemiology of the disease to predict its behaviour in different regions and to devise provisional chemical control schedules. Copper fungicides still remain the most widely used chemicals but some of the more modern systemic fungicides are showing great potency. Advances in spraying techniques, with concomitant reductions in volumes and doses, have made chemical control more economic. The chemical control of coffee rust is greatly influenced by socioeconomic and physiographic factors as well as by the agronomy of the crop. Resistant varieties have so far played little part in coffee rust control, but some lines from Arabica-Robusta hybrids may show durable resistance.

The relationship between mycelial growth and initiation of sclerotia in a single isolate of S. rolfsii Sacc. was investigated (1) in Petri dishes of different sizes, (2) in colonies (part or whole) transferred to fresh media and/or Petri dishes, and (3) in colonies having different rates of mycelial growth. Initiation appears to be regulated by the growing hyphae at the periphery of the mycelial mat. In dishes of 5, 7, 9 and 13 cm. diam. initials did not appear until the lateral extension of the mycelium was restricted. In colonies on millipore filters transferred to fresh plates where further extension of the mycelium could occur, initiation of sclerotia was suppressed. On central disks 5 cm. diam. removed from colonies at different stages of growth, initiation began earlier than on undisturbed colonies of comparable age. When the growth rate on a particular medium was altered, either by incubating at a lower temperature during the early stages or by using different inocula, there was a corresponding change in the number of initials formed. An analysis of data from seventeen experiments showed a highly significant, positive correlation between growth rate and number of initials produced. The significance of these results is discussed. It is suggested that initiation of sclerotia depends on the accumulation in the hyphae of substances which are metabolized in a different way from that involved in mycelial growth.

SUMMARY Devices are described which were used to catch rain-dispersed Colletotrichum conidia within and between coffee trees infected with coffee berry disease (CBD). The amount of CBD inoculum dispersed was related to the number of diseased and sporulating berries but not to the sporulating capacity of the fungus in maturing bark. Wet conditions encouraged spore production and dispersal, and spraying with fungicides prolonged sporulation of diseased berries. The amount of pathogenic inoculum, subsequent disease development and crop losses were greatly increased by the presence of only a few diseased berries during growth of the young crop. Spore concentrations were greatest close to diseased berries, but most spores within trees were dispersed downwards through the canopy. Some spores were dispersed between trees by wind-driven rain-splash and vectors such as pickers. Inoculum sources in tree tops are most important during CBD epidemics and disease can be restricted by removing or spraying the tops of multiple-stem trees. Fungicide applied to tree tops effectively controls CBD, because spores dispersed during rain are accompanied by redistributed fungicide

The terminal smut whip, produced by modified activity of the apical meristems of diseased canes, releases inoculum over a period of about 3 months. The maximum rate of release (c 8 × 106 spores/day) occurs in the middle of this period. Although some deposition occurs on various cane surfaces including lateral buds, infection in the field is chiefly restricted to young tiller buds as they emerge through the soil. Irrigation substantially increases the severity of disease; the presence of liquid water appears to be necessary for spore germination. Fresh sugarcane debris and washings from sugarcane leaves increase spore germination at the surface of soils. Considerable germ-tube elongation occurs on cane surfaces and multiplication of inoculum through the production of secondary sporidia can occur on mature leaves and cut surfaces. The period from infection to whip production is about 6 months under field conditions. Although multiplication of inoculum occurs during the life of the crop, a decreasing tillering rate causes the crop to become more resistant so that epidemic increase tends to be linear. It is considered that removal of diseased plants early in the crop cycle and the protection of young ratoon crops from infection are most important in checking the initial stages of an epidemic. The disease is particularly favoured under conditions of surface irrigation in hot areas.

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