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Bombax ceiba L. (Bombacaceae) is a common deciduous tree introduced to Egypt for ornamental purposes. This study was conducted to describe the impact of B. ceiba leaf litter on plant cover and species diversity in a new urban ecosystem. In general, the sites under B. ceiba canopy attained lower species richness, diversity, plant cover and biomass than in adjacent open areas. Winter species were more adversely affected than summer ones. Both Amaranthus viridis and Trigonella hamosa were completely absent from the sites involving Bombax, whereas the cover of Euphorbia prostrata, Lolium temulentum and Paspalum dilatatum were stimulated. Moreover, the litter-affected soils were more abundant in organic matter and nutrients. Mulching with B. ceiba leaf litter in greenhouse reduced the emergence and growth of Amaranthus viridis, Melilotus indicus and Trifolium resupinatum, whereas the negative effect of litter amendment was pronounced for the former species only. The HPLC analysis confirmed the presence of some free phenolics and flavonoids. Gallic acid was abundant amongst phenolics (90.3 μg g−1 leaf dry weight) whereas quercetin and apigenin were common amongst flavonoids (8.7 and 6.7 μg g−1 leaf dry weight, respectively). In conclusion, the reduction in species diversity and plant cover in the understorey vegetation was attributed to the effects of the tree litter. The test due to litter amendment into soil denotes that allelopathy may have function at least for some species. Besides, the statistical differences between mulching and litter amendment indicate that reduction in plant cover and diversity could be related to the mechanical effect of the litter. These findings suggest that B. ceiba affects species diversity and plant cover and, therefore, represents a threat to the plant communities in the new urban areas. The severity of the litter impact was correlated with seed size, litter amount and the season coinciding with leaf abscission.

Wild cereals have been harvested all over the world by hunter-gatherer with evidences as much in South America as in Australia, North America and Subsaharian Africa. In some places there are still used for human consumption. The goal of this paper is to document phytoliths in inflorescence axis, and in kernels/inflorescences/bracts of several native Argentinian wild grasses in order to get an archaeobotanical comparative referential for the analyses of residues from both food plant processing activities and consumption. We could observe typical phytolith morphotypes from specific anatomical parts of grasses, but non-taxon specific, as well as non-diagnostic phytolith morphotypes, but characteristic of the phytolith association of a certain taxa. They all allow us to get a more complete view of the phytolith production for each specific taxon. Results obtained by Morisita Test-Past Program-suggest a trend to the organization at the level of subfamilies for the phytoliths production in the 14 species studied. Species of the genus Aristida and Cynodon show an intra-generic consistency in the production of phytoliths morphotypes per organ, and tend to be grouped in cluster analysis. In some species as Cynodon dactylon, Bromus catharticus, Aristida adscensionis, Sorghastrum pellitum and Paspalum dilatatum it can be noted a similarity in the morphotype production as much in inflorescence axis as in kernels/inflorescences/bracts. A morphological continuum between similar morphotypes could be also established, by comparing series of shapes within fragments of silicified plant tissue. Finally, we consider phytolith production from potential useful plant parts for human consumption, in a way as their presence alone, or associated with starch grain analyses, as showed by a previous work, could be used for regional dietary reconstructions. Our results from inflorescence/kernel phytolith production give us good expectation to be able to identify them in archaeological contexts. Fil: Babot, Maria del Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Estudios Sociales. Universidad Nacional de Tucumán. Instituto Superior de Estudios Sociales; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Arqueología y Museo; Argentina Fil: Musaubach, María Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Cátedra de Etnografía; Argentina. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Museo Etnográfico "Juan B. Ambrosetti"; Argentina Fil: Plos, Anabela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División de Plantas Vasculares; Argentina

Urban greening may enhance the distribution of exotic species that represent a threat for the native species in new urban systems. Paspalum dilatatum Poir. is one of the exotic naturalized species dominating in gardens of new urban ecosystems in Egypt. This study was conducted to evaluate the allelopathic interference of such species on the native plants in these habitats. The field study showed that the plots infested with Paspalum attained lower coverage, diversity and biomass of native plants than those free from it. Amaranthus viridis and Dactyloctenium aegyptium were completely absent from the sites involving P. dilatatum. Moreover, Paspalum-infested soils were of more water content, available nitrogen and extremely higher nitrogenase activity. In a greenhouse experiment, the rhizosphere soil under Paspalum reduced germination and growth of some native species, namely, Amaranthus viridis, Medicago lupulina, Melilotus indicus and Plantago amplexicaulis. Moreover, growth inhibition was inversely related to the seed size of these tested species. The spectrophotometric analysis revealed that higher contents of phenolics and flavonoids were detected in the Paspalum-infested soils in comparison with free ones. Besides, the high performance liquid chromatographic (HPLC) analysis indicated the presence of some free phenolics and flavonoids with higher concentrations in Paspalum-infested soils. The results indicate that the exotic naturalized P. dilatatum had negative effects on coverage, biomass and diversity of the native species in urban gardens. The obtained inhibition in these criteria was not attributed to soil characteristics. Furthermore, the significant reduction in germination and growth of the target species under greenhouse conditions could be attributed to the higher phenolic and flavonoid contents in the Paspalum-infested soils. These findings suggest that allelopathy had, at least, partial role in the negative impact caused by P. dilatatum. This species may also represent a threat for the native plant communities in new urban ecosystems.

Glyphosate is a systemic non-selective herbicide, the most widely used in the world. Alongside with its use in agricultural and forestry systems, this herbicide is used in grasslands in late summer with the aim of promoting winter species with the consequent increase in stocking rate. However, its effects on non-target organisms, such as arbuscular mycorrhizal fungi (AMF), are unclear. Arbuscular mycorrhizal fungi (AMF) colonize the root of more than 80% of terrestrial plants, improving their growth and survival, and therefore playing a key role in ecosystem structure and function. The aim of this work was to investigate the possible pathways through which glyphosate application affects AMF spores viability and root colonization in grassland communities. Our hypothesis is that glyphosate application can damage AMF directly (through contact with spores and external hyphae) or indirectly through the changes it generates on host plants. The experiment had a factorial array with three factors: (1) plant species, at two levels (Paspalum dilatatum and Lotus tenuis), (2) doses of glyphosate, at three levels (0 l ha−1, 0.8 l ha−1 and 3 l ha −1), and (3) application site, at two levels: soil (direct pathway) and plant foliage (indirect pathway). Spore viability was reduced even under the lowest glyphosate rate, but only when it was applied on the soil. Total root colonization for both species was similarly decreased when glyphosate was applied to plant foliage or on soil, with no difference between 0.8 and 3 l ha−1. The number of arbuscules was 20% lower when glyphosate was applied on plant foliage, than when it was applied on the soil. Our findings illustrate that glyphosate application negatively affects AMF functionality in grasslands, due to different causes depending on the herbicide application site. While, under field conditions, the occurrence of direct and/or indirect pathways will depend on the plant cover at the time of glyphosate application, the consequences of this practice on the plant community structure will vary with the mycorrhizal dependence of the species composition regardless of the pathway involved., Facultad de Ciencias Naturales y Museo

Forages cover extensive areas of agricultural land in Australia, but only limited data is available on the potential of these different forages to sequester soil organic carbon (SOC) under best practice management. This study was undertaken on a brown dermosol in the warm temperate climate of Camden, Australia, over three years, to evaluate a range of perennial and annual forages for their impact on SOC and soil nitrogen (N). The C4 perennial forages kikuyu (Pennisetum clandestinum Hochst. ex. Chivov.) and paspalum (Paspalum dilatatum Poir.) increased (P 0.05). The high productivity of legumes led to high mean estimate of N fixation of up to 726 kg N ha/year over the three years. However, as most of the legume shoot production of the forage species was removed there, was a negligible increase in soil N levels. This study has shown that the choice of forage has a large impact on the amount of carbon that can be sequestered into the soil.

a b s t r a c t Water for irrigated agriculture is becoming increasingly scarce worldwide and this has led to interest in deficit irrigation (DI) as a means of reducing forage and crop water requirements. While perennial ryegrass (Lolium perenne L.) dominates the forage base on Australian dairy farms, its ability to extract water from the soil profile under DI compared to other species has not been documented under best practice management. Changes in soil water content (SWC) of twenty two perennial and annual forage and crop species were evaluated over three years to assess the ability of these forages to extract water from the soil profile compared to perennial ryegrass under DI on a brown Dermosol, over three years at Camden, Australia. Seven perennial and three annual forage species created a greater (P < 0.001) soil water deficit (SWD) to 150 cm than perennial ryegrass. Paspalum (Paspalum dilatatum Poir.) created the largest SWD to 150 cm of 226 mm, which was 78 mm greater than perennial ryegrass for the same year. Estimated plant root depth was greater than 150 cm for 11 of 12 perennial forage species, but less than 150 cm for seven of 11 annual forage species. This study showed that there were large differences between values of maximum extractable water for the range of forage species evaluated, which has implications for reducing irrigation requirements and reducing recharge.

A mixture of common Southern Piedmont (USA) grassland species (Lolium arundinacea, Paspalum dilatatum, Cynodon dactylon and Trifolium repens) was exposed to O(3) [ambient (non-filtered; NF) and twice-ambient (2X) concentrations] and fed to individually caged New Zealand white rabbits (Oryctolagus cuniculus) in a digestibility experiment. Forages and feed refusals were analyzed for concentrations of total cell wall constituents, lignin, crude protein, and soluble and hydrolyzable phenolic fractions. Neutral detergent fiber and acid detergent fiber digestibility by rabbits were significantly lower for 2X than NF forage. Decreased digestibility could not be attributed to lignin concentrations, but was associated with increased concentrations of acid-hydrolyzable and saponifiable phenolics. Exposure of forage to elevated O(3) resulted in decreased digestible dry matter intake by rabbits. Elevated O(3) concentrations could be expected to have a negative impact on forage quality, resulting in decreased nutrient utilization by mammalian herbivores in Southern Piedmont grasslands under projected future climate scenarios.

The grass Paspalum dilatatum Poir. subsp. dilatatum inhabits periodically flooded lowlands as well as non-flooded uplands of the flooding Pampa grasslands (Argentina), while P. dilatatum Poir. subsp. flavescens Roseng., B.R. Arrill. & Izag. inhabits only the upland sites. An experiment was designed to determine if there is local adaptation to flooding in physiological, anatomical and leaf morphological traits. To this end, plants of these populations were subjected to flooding (6 cm water depth) and control conditions (watered daily) for 60 days in an experimental garden. Flooded plants of the subsp. dilatatum from the lowland had 35% higher photosynthesis compared to controls without affecting their stomatal conductance, transpiration rate and leaf water potential. By contrast, both subsp. dilatatum and subsp. flavescens from the upland did not increase their photosynthesis, and had reduced their stomatal conductance and leaf transpiration rate by 35% and 45% when growing in flooded conditions. Upland populations had higher leaf water potential with respect to controls. All populations had high constitutive root aerenchyma (28–42%), and leaf sheath porosity increased by 75% in flooded conditions (from 22–28% to 35–48%). Leaf lengthening differed among populations according to their habitat: subsp. dilatatum from the lowland was the only one that had longer leaf sheaths and blade lengths when flooded. In contrast, flooded plants of subsp. dilatatum from the upland only increased leaf sheath length while subsp. flavescens neither increased leaf blade nor leaf sheath. In conclusion, both the physiological performance and the leaf length plasticity differed among populations. The results agree with those expected based on the species’ habitat, and indicate the better adaptation to the flood-prone habitat of P. dilatatum subsp. dilatatum taken from a lowland area.

Kikuyu grass, Pennisetum clandestinum Hochst. ex Chiov., is an important pasture species in many subtropical areas. Infestations of yellow sugarcane aphid (YSA), Sipha flava (Forbes) (Homoptera: Aphididae), have reduced kikuyu forage production in Hawaii. A novel method was developed to screen cultivars of kikuyu, and species of other forage and turf grasses for resistance to YSA. Kikuyu germplasm differed significantly in response to YSA with certain kikuyu hybrids more resistant to YSA than the common cultivar. However, even the kikuyu cultivars with the lowest damage ratings were considered only to be moderately resistant to YSA. Other forage grass species differed significantly in YSA damage, with Pacific fountain [Pennisetum macrostachys (Brongn.) Trin.], dallis (Paspalum dilatatum Poir.), torpedo (Panicum repens L.), tall fescue (Festuca arundinacea Schreb.), signal [Urochloa brizantha (Hochst. ex A. Rich.) R.D. Webster, formerly known as Brachiaria decumbens], bahia (Paspalum notatum Flugge), small buffalo (Panicum coloratum L.), velvet (Holcus lanatus L.), and switch (Panicum virgatum L.) grasses considered to be resistant to YSA. Turf grass species also differed significantly in YSA injury, with seashore paspalum (Paspalum vaginatum Sw.), St. Augustine [Stenotaphrum secundatum (Walter) Kuntze], and Japanese lawn (Zoysia japonica Steud.) grasses evaluated as resistant. Reduction of pasture forage by YSA could be ameliorated either by utilization of moderately tolerant kikuyu hybrids or resistant forage grass species.

A field experiment to study the effects of various pre- and post-emergence herbicides on weed infestation and on corm and cormel production in three gladiolus ( Gladiolus spp.) cultivars was carried out during 1997–2000 at IHBT, Palampur. The main weeds infesting the experimental farm were Ageratum conyzoides , Gnaphalium peregrinum , Plantago lanceolata , Cynodon dactylon , Amaranthus viridis , Paspalum dilatatum , Portulaca oleracea , Euphorbia hirta , Oxalis corniculata , Trifolium repens , Imperata cylindrica and Digitaria adscendance. Of the various pre-emergence herbicides tested, atrazine and alachlor, both at 1.0 kg a.i./ha, significantly lowered the germination percentage of the gladiolus cormels. Pendimethalin 1.0 kg a.i./ha reduced the germination of the cormels to a lesser extent. Pre-emergence application of oxyfluorfen 0.25 kg a.i./ha gave the lowest weed count and weed dry matter accumulation, comparable with weed free treatment, at 90 days after planting (DAP). This treatment along with post-emergence application of glyphosate (1.0 kg a.i./ha at 90 DAP) gave best results at 180 DAP. The corm and cormel production was significantly higher in oxyfluorfen treatment. The results indicate that application of oxyfluorfen as pre-emergence herbicide followed by application of glyphosate at 90 DAP could be an effective treatment for weed control in gladiolus cormels.

Water supply affects seed germination and seedling establishment of shallow-rooted warm-season grasses. This may explain the difficulty of incorporating Dallisgrass (Paspalum dilatatum Poir.) into humid temperate grasslands through interseeding. We studied the effects of water availability on seed germination and seedling growth under controlled conditions to determine which step of the establishment process was most affected. In a laboratory experiment, seeds were germinated at 0, -0.25, -0.5, -0.75, and -1 MPa water availability generated with solutions of polyethylene glycol. Although both maximum rate and total germination (P < 0.05) significantly decreased with increased water stress, the speed of germination was even more sensitive. In a greenhouse experiment, variations in seedling emergence and morphological characteristics were measured in relation to water availability. Pregerminated and dry seeds were sown in pots that were irrigated at 1-, 2- , 4-, or 7-day intervals. This species showed high sensitivity to water stress during germination and early emergence. High emergence was obtained from the daily irrigation treatment. In all other treatments, where watering frequency was extended, emergence was decreased. Results suggest that rapid germination and early adventitious root growth can be obtained only with reliable availability of water. These conditions, combined with the high temperatures required for breaking seed dormancy, occur infrequently, explaining the difficulty of achieving successful establishment of Dallisgrass. Water availability during seed germination and seedling emergence is a critical factor for survival of this species.

A digestion trial, with four wethers fitted with rumen cannulas, was carried out to assess the effect of inclusion of a warm season dallis grass (Paspalum dilatatum) on the nutritive value of pastures during spring, summer and autumn. The design was a split-plot with a 2 x 3 factorial arrangement. Dry matter digestibility (DMD), in vivo, was higher (P 0.05) on water soluble nitrogen, potentially degradable N, available fraction of total N consumed and fractional rate of degradation of N, while season had a significant (P < 0.05) effect on the same parameters. Effective degradability was higher (P < 0.05) for pastures without dallis grass (722 versus 687 g kg -1 ) and also higher (P < 0.05) in autumn (939 g kg -1 ) than in summer (665 g kg -1 ) and spring (549 g kg -1 ). Rumen pH was higher (P < 0.05) for pastures without dallis grass (7.01 versus 6.66). It is concluded that there exists a distinct season effect on nutritive value of pastures and that the inclusion of dallis grass may improve the use of dietary nitrogen.

The effects of sward structure and bite weight ( W ) on bite rate in cattle ( Bos taurus ) were examined to explain the behavioural components of handling time. Three oesophageally fistulated steers grazed homogeneous, hand-constructed swards of Paspalum dilatatum Poir. or Medicago sativa L., in a sward area of approximately 0.36 m 2 , for 60–212 s. Three types of jaw movements (JM) were distinguished: manipulative JM that gather herbage into the mouth, chewing JM, and compound JM that manipulate fresh herbage and chew herbage already in the mouth within one cycle of opening and closing of the jaws. Intake rate ( I , g min −1 ) was a discontinuous asymptotic function of W: I = W max (0.0337,0.0201 + 0.0095 ∗ W) . Sward height and bulk density did not significantly affect I beyond the effects of W . Time per bite was 2.0 s when W ≈ 1.29 g, and increased linearly with W when W >1.29 g. Linear regression of time per bite on total number of JM explained 96% of the variance. A non-linear relation between total JM per bite and W comprised a linear relation between total chews per bite and W , and a constant number of total manipulative JM per bite. When W increased up to c . 1.5 g, chewing requirements were met by compound JM. Above W of 1.5 g, the overlap of chewing and manipulation reached a maximum, so total JM increased with W . The importance of compound JM and the potential for overlap between chewing and searching are discussed in the context of foraging models.

Summary Tissue culture techniques provide unique opportunities to introduce variability into vegetatively propagated or apomictic plants. We studied 45 regenerates of apomictic common dallisgrass ( Paspalum dilatatum Poir.) derived via tissue culture to search for variability in characteristics related to stress tolerance. Plants were grown in replicated field nurseries. Characteristics measured were heat tolerance as determined by both the solute leakage and tiller survival methods, leaf epicuticular wax content, and survival under severe water stress. In each test, one or more of the regenerates differed from common dallisgrass. In the solute leakage test, two entries had less damage than common, while seven were damaged more than common. In the tiller survival test, two entries were significantly lower in mortality than common dallisgrass. Three entries had better survival than common in the water stress test, while four entries were significantly higher in mortality. The range in wax values observed in the regenerates was relatively narrow. However, two entries were significantly higher in wax than common, but none were significantly lower. In several cases, some entries differed from common for more than one of the parameters tested, although the majority of the entries did not differ from and probably were similar to common dallisgrass. These findings demonstrate that somaclonal variation expressed in plants regenerated through tissue culture include basic physiological characteristics that influence drought and heat tolerance. Because these changes are in an obligate apomict, they are permanently fixed and will be expressed in subsequent generations.

Plant regeneration from cultured immature inflorescences of Paspalum dilatatum was obtained by somatic embryogenesis. Embryonic callus was initiated from immature inflorescences (5–10 mm length) on Murashige and Skoog (MS) medium supplemented with 2.0–10.0 mg·l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and solidified with 0.2% (w/v) Gellan Gum. Somatic embryos could be induced at all concentrations of 2,4-D, but the maximal frequency of explants which produced somatic embryos occurred on medium containing 10.0 mg·l−1 2,4-D. Somatic embryos developed and germinated precociously when embryogenic calli were transferred to a medium containing 1.0 mg·l−1 each of kinetin and gibberellic acid (GA3). All regenerants were successfully grown to maturity. The embryogenic calli maintained their embryogenic capacity on Murashige and Skoog (MS) medium with 1.0 mg·l−1 2,4-D for more than 1 year.

Protoplasts were isolated from embryogenic suspension cells of apomictic dallisgrass (Paspalum dilatatum Poir.). The respective suspension cultures were initiated from immature inflorescence-derived embryogenic callus. Previous to protoplast isolation, suspension cells were treated with Murashige and Skoog (MS) liquid medium without sucrose and hormones. Due to this pretreatment protoplast yield and viability were dramatically increased. A maximum protoplast yield of 4–6 × 106· −1 fresh weight was obtained. Cell division and colony formation from pretreated protoplasts were found to be best in an agarose solidified KM8p medium at a density of 5–8 × 105· ml−1. The plating efficiency, based on colony formation after 2 weeks of culture, was 0.5–0.8%. Protoplast-derived colonies were transferred to a solidified MS medium containing 1.0 mg · 1−1 2,4-dichlorophenoxyacetic acid (2,4-D) for callus proliferation. The calli formed embryonic structures which gave rise to green plants in 0.2% (w/v) Gellan Gum solidified MS medium with 1.0 mg·l−1 naphthaleneacetic acid (NAA) and 0.2 mg·l−1 benzylaminopurine (BAP). The regenerated plantlets were transferred to 1 2 MS hormone-free medium for further growth and root formation. Rooted plants could be transferred to soil.

Intensive fodder production systems were compared under irrigation in western New South Wales. The three basic systems studied were: 1. (1) Annual forages ( Sorghum bicolor × S. sudanense plus Avena sativa ). 2. (2) Perennial pasture ( Paspalum dilatatum ). 3. (3) Perennial forage ( Medicago sativa ). The first two systems included nitrogen fertilizer or legume options, while the last had the option of including a perennial sorghum. Dry matter production was highest in the annual forage system (maximum of 30·5 tonnes ha −1 year −1 ), although annual establishment costs were higher than for perennial systems. The perennial pasture yielded 21·5 tonnes ha −1 year −1 but, like the annual forage system, 250 kg N ha −1 year −1 was required to obtain this yield. The perennial forage yielded 19·8 tonnes ha −1 year −1 without nitrogen fertilizer. Furthermore, it yielded more digestible dry matter and nitrogen than any other system. Although the annual forage system was the most profitable when based upon a set price for hay, the best system for grazing was difficult to determine; factors relating to grazing management are discussed.

Intact cores of a Vitrandept soil containing a ryegrass ( Lolium perenne L.), white clover ( Trifolium repens L.), paspalum ( Paspalum dilatatum Poir.) pasture were subjected to simulated winter-spring temperature regimes in controlled-environment rooms. Treatments involved “mild” (11°C days, 7°C nights) or “cold” (varying down to 6°C days, 1°C nights) winter temperatures and applications of 15 N-enriched ammonium sulphate (5 g N m −2 ) in “early” or “late” winter. Pasture growth without added N was slower during the “cold winter” than the “mild winter”. However, the pasture response to N applied in early winter was larger during the “cold winter” than the “mild winter”. Plant uptake of added 15 N was rapid and complete by 1 month after application. It was unaffected by winter temperatures. Most of the 15 N absorbed after the “early winter” application was present initially in the roots and was later translocated to the shoots. The amount of 15 N remaining in soil was similar for all treatments and a significant component was in the microbial biomass. Microbial 15 N was larger following the “early winter” than the “late winter” application and was larger for the “cold winter” regime. This indicates that more fertilizer N is temporarily immobilized in the microbial biomass at low soil temperatures.

Plants of Paspalum dilatatum and Lolium multiflorum were grown in pots at different densities. Half of the plants at each density received additional red light at their bases by means of light-emitting diodes. Density reduced both the proportion of incident radiation intercepted per plant and the red/far-red ratio of the light at plant bases. Tillering decreased with density in both species. P. dilatatum plants also had fewer reproductive tillers and expanded leaves and a higher mortality of young vegetative tillers in denser stands. In both species the enrichment with red light did not increase tillering of isolated plants, but increased it in stands grown at relatively low densities with small degrees of mutual shading. At these densities P. dilatatum plants achieved the number of tillers of isolated plants. Moreover, red light increased vegetative tiller death in the P. dilatatum dense canopy. These results suggest that low red/far-red ratios might preclude morphogenic responses to density before an important depletion in energy availability takes place.

The resident and transient fungal microflora present on leaf surfaces of Paspalum dilatatum, Salix babylonka and Eucalyptus stellulata were studied using leaf-imprint and spore-fall techniques of isolation. The spore-fall technique is thought to indicate the actively growing and sporulating resident fungi on the surfaces of leaves. The leaf-imprint method isolates both resident and transient fungi. The difference between species isolated by both methods gives a measure of the transient microflora on leaf surfaces. The evidence indicated that the surfaces of living leaves of different plant species support distinctive fungal populations.

Conidia of Ascochyta paspali present in cow's saliva immediately after ingestion of infected paspalum were capable of causing infection. Conidia could be recovered up to 30 min after grazing had ceased. This is the first report of cattle acting as a vector of a plant pathogen and the aggregation pattern of leaf blight is attributed to the grazing pattern of cows within infected fields.