scholarly journals Onorchard habitats for Nysius huttoni an important kiwifruit passenger pest

2014 ◽  
Vol 67 ◽  
pp. 326-326
Author(s):  
C.A. Rowe ◽  
M.G. Hill ◽  
D.P. Logan
Keyword(s):  
Native Species ◽  
Host Plants ◽  
Ground Vegetation ◽  
Preliminary Survey ◽  
Weed Species ◽  
Quarantine Pest ◽  
Polygonum Aviculare ◽  
Brassica Crops ◽  
Wide Range ◽  
High Incidence

Nysius huttoni is a native species of wheat bug which is an occasional quarantine pest on export kiwifruit Wheat bug has a wide range of host plants including wheat and brassica crops as well as many weed species The kiwifruit harvest of 2013 had a high incidence of wheat bug finds on fruit in packhouses In response an orchard survey was undertaken to identify orchard habitats used by wheat bug Twentyfive orchards where wheat bug was found during packing in 2013 were surveyed from the Te Puke area from February to March At each orchard four habitats were searched (1) ground vegetation under the kiwifruit canopy (2) the loadout zone (3) edge of the loadout zone and (4) grassland surrounding the was found in and around the loadout zone associated with weed species notably Polygonum aviculare the dominant weed species in loadout zones No wheat bug was found under the kiwifruit canopy and the remaining 4 were found in grassland This preliminary survey suggests that the risk of wheat bug infestation can be reduced considerably by keeping loadout zones free of weeds during spring and summer

scholarly journals North American channel catfish, Ictalurus punctatus: a neglected but potentially invasive freshwater fish species?

2021 ◽  
Vol 23 (5) ◽  
pp. 1563-1576 ◽  
Author(s):  
Phillip J. Haubrock ◽  
Gordon H. Copp ◽  
Iva Johović ◽  
Paride Balzani ◽  
Alberto F. Inghilesi ◽  
...  
Keyword(s):  
North America ◽  
Ictalurus Punctatus ◽  
Channel Catfish ◽  
North American ◽  
Disease Transmission ◽  
Native Species ◽  
Assessment Protocol ◽  
South Italy ◽  
Wide Range ◽  
North And South

AbstractThe North American channel catfish Ictalurus punctatus has been introduced to several locations in Europe but has received little or no scientific study despite its invasive attributes, including prolific reproduction, tolerance to a wide range of conditions, opportunistic feeding, at least partial ‘predator release’, and some evidence of environmental impacts (e.g. disease transmission). To assess the species’ potential invasiveness and the likely risks to native species and ecosystems in Europe, available literature from both North America and Europe was reviewed and used to carry out risk screenings of the species for the risk assessment areas, North and South Italy, using the Aquatic Invasiveness Screening Kit (AS-ISK), which was followed by a more detailed evaluation (for both North America and Europe) of the species’ potential impacts using the Environmental Impact Classification of Alien Taxa (EICAT) assessment protocol. The AS-ISK score indicated that channel catfish is likely to pose a high risk of being invasive in both North and South Italy, with EICAT scores indicating “Major” impacts for both North America and Europe, at high and medium confidence levels, respectively. The present results emphasise the urgent need to carry out in-depth studies on introduced populations of this species to understand better its invasive potential so as to inform management decisions on the appropriate control or eradication measures for invaded water bodies.

Seed germination biology of sweet acacia (Vachellia farnesiana) and response of its seedlings to herbicides

Weed Science ◽  
2021 ◽  
pp. 1-19
Author(s):  
Bhagirath S. Chauhan ◽  
Shane Campbell ◽  
Victor J. Galea
Keyword(s):  
Sodium Chloride ◽  
Seed Germination ◽  
Development Stage ◽  
Hot Water ◽  
Control Treatment ◽  
Similar Species ◽  
Weed Species ◽  
Physical Dormancy ◽  
Seed Biology ◽  
Wide Range

Abstract Sweet acacia [Vachellia farnesiana (L.) Willd.]is a problematic thorny weed species in several parts of Australia. Knowledge of its seed biology could help to formulate weed management decisions for this and other similar species. Experiments were conducted to determine the effect of hot water (scarification), alternating temperatures, light, salt stress, and water stress on seed germination of two populations of V. farnesiana and to evaluate the response of its young seedlings (the most sensitive development stage) to commonly available POST herbicides in Australia. Both populations behaved similarly to all the environmental factors and herbicides; therefore, data were pooled over the populations. Seeds immersed in hot water at 90 C for 10 min provided the highest germination (88%), demonstrating physical dormancy in this species. Seeds germinated at a wide range of alternating day/night temperatures from 20/10 C (35%) to 35/25 C (90%) but no seeds germinated at 15/5 C. Germination was not affected by light, suggesting that seeds are nonphotoblastic and can germinate under a plant canopy or when buried in soil. Germination was not affected by sodium chloride concentrations up to 20 mM and about 50% of seeds could germinate at 160 mM sodium chloride, suggesting its high salt tolerance ability. Germination was only 13% at −0.2 MPa osmotic potential and no seeds germinated at −0.4 MPa, suggesting that V. farnesiana seeds may remain ungerminated until moisture conditions have become conducive for germination. A number of POST herbicides, including 2,4-D + picloram, glufosinate, paraquat and saflufenacil, provided >85% control of biomass of young seedlings compared with the nontreated control treatment. Knowledge gained from this study will help to predict the potential spread of V. farnesiana in other areas and help to integrate herbicide use with other management strategies.

Ustilago hypodytes. [Descriptions of Fungi and Bacteria].

1984 ◽  
Author(s):  
J. E. M. Mordue
Keyword(s):  
New Zealand ◽  
North America ◽  
South America ◽  
Root System ◽  
Geographical Distribution ◽  
Host Plants ◽  
Meristematic Tissue ◽  
Wide Range ◽  
Vegetative Multiplication ◽  
Established Infection

Abstract A description is provided for Ustilago hypodytes. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: A wide range of grasses, including species of Agropyron (many), Ammophila, Brachypodium, Bromus, Calamagrostis, Diplachne, Distichlis, Elymus (many), Festuca, Glyceria, Hilaria, Hordeum, Haynaldia, Lygeum, Melica, Orysopsis, Panicum, Phalaris, Phleum, Poa (many), Puccinellia, Secale, Sitanion, Sporobolus, Stipa (many), and Trisetum. DISEASE: Stem smut of grasses. GEOGRAPHICAL DISTRIBUTION: Chiefly a temperate species found in Europe (including Denmark, Finland, France, Germany, Hungary, Italy, Romania, Sweden, Switzerland, UK, USSR, Yugoslavia) and North America (Canada, USA) and extending to central and South America (Argentina, Peru, Uruguay), N. Africa (Libya, Morocco, Tunisia), Japan, Australia and New Zealand. TRANSMISSION: Not fully understood, though inoculation experiments have demonstrated that infection occurs in mature vegetative plants (possibly through meristematic tissue), not seeds or flowers (22, 240; 24, 511). Once established, infection is systemic, probably overwintering in the root system and spreading by vegetative multiplication of host plants as well as from plant to plant (24, 511; 19, 720).

Germination Biology of Sesbania (Sesbania cannabina): An Emerging Weed in the Australian Cotton Agro-environment

Weed Science ◽  
2018 ◽  
Vol 67 (1) ◽  
pp. 68-76 ◽  
Author(s):  
Nadeem Iqbal ◽  
Sudheesh Manalil ◽  
Bhagirath S. Chauhan ◽  
Steve W. Adkins
Keyword(s):  
Seed Germination ◽  
Management Strategies ◽  
Moisture Stress ◽  
Integrated Weed Management ◽  
Burial Depth ◽  
Weed Species ◽  
Physical Dormancy ◽  
Sesbania Cannabina ◽  
Wide Range ◽  
The Impact

AbstractSesbania [Sesbania cannabina(Retz.) Pers.] is a problematic emerging weed species in Australian cotton-farming systems. However, globally, no information is available regarding its seed germination biology, and better understanding will help in devising superior management strategies to prevent further infestations. Laboratory and glasshouse studies were conducted to evaluate the impact of various environmental factors such as light, temperature, salt, osmotic and pH stress, and burial depth on germination and emergence of two Australian biotypes ofS. cannabina. Freshly harvested seeds of both biotypes possessed physical dormancy. A boiling-water scarification treatment (100±2 C) of 5-min duration was the optimum treatment to overcome this dormancy. Once dormancy was broken, the Dalby biotype exhibited a greater germination (93%) compared with the St George biotype (87%). The nondormant seeds of both biotypes showed a neutral photoblastic response to light and dark conditions, with germination marginally improved (6%) under illumination. Maximum germination of both biotypes occurred under an alternating temperature regime of 30/20 and 35/25 C and under constant temperatures of 32 or 35 C, with no germination at 8 or 11 C. Seed germination of both biotypes decreased linearly from 87% to 14% with an increase in moisture stress from 0.0 to −0.8 MPa, with no germination possible at −1.0 MPa. There was a gradual decline in germination for both biotypes when imbibed in a range of salt solutions of 25 to 250 mM, with a 50% reduction in germination occurring at 150 mM. Both biotypes germinated well under a wide range of pH values (4.0 to 10.0), with maximum germination (94%) at pH 9.0. The greatest emergence rate of the Dalby (87%) and St George (78%) biotypes was recorded at a burial depth of 1.0 cm, with no emergence at 16.0 cm. Deep tillage seems to be the best management strategy to stopS. cannabina’s emergence and further infestation of cotton (Gossypium hirsutumL.) fields. The findings of this study will be helpful to cotton agronomists in devising effective, sustainable, and efficient integrated weed management strategies for the control ofS. cannabinain cotton cropping lands.

scholarly journals PERSPECTIVES OF BREEDING OF VEGETABLE CROPS OF FABACEAE FAMILY TO BEAN YELLOW MOSAIC VIRUS (Potyvirus, Potyviridae) RESISTANCE IN THE CONDITIONS OF MOSCOW REGION

2018 ◽  
pp. 77-83
Author(s):  
I. A. Engalycheva ◽  
E. G. Kozar ◽  
A. A. Antoshkin ◽  
E. P. Pronina ◽  
Y. G. Volkov ◽  
...  
Keyword(s):  
Causative Agent ◽  
Host Plants ◽  
Far East ◽  
Diagnostic Methods ◽  
Moscow Region ◽  
Kidney Bean ◽  
Yellow Mosaic Virus ◽  
Distribution Area ◽  
Sources Of Resistance ◽  
Wide Range

In the context of climate change phytomonitoring of the prevalence of the most common viral pathogens on the crops becomes even more important, because during the last decades the harmfulness of those pathogens, in particular Bean yellow mosaic (BYMV) has grown in intensity. The causative agent as the most members of Рotyvirus genus, has a wide range of host plants belonging to various families including Fabaceae. In Russia the virus was for the first time identified in the south of the Far East, where in the middle of XX century the massive damage of clove, lupine, sweet pea, pea, bean and Russian bean was observed. The distribution area of BYMV considerably expanded after advancement of heat-loving leguminous crops towards north. During the last years epiphytotics were reported in the planted crops of kidney bean (Phasйolus vulgбris L.), and Russian bean (Faba bona Medik. var. major Harz.) under conditions of temperate continental climate of nonchernozem belt in the RF. It is not feasible to eradicate natural BYMV foci, while the control of the causative agent carriers as a preventive measure is not very effective. There fore at present the search for the sources of resistance to BYMV and creation of parent selection material is a priority area of our phytopatologic research. At the present stage the tasks included: identification and study of the properties of BYMV Moscow isolates; integral assessment of resistance and other economically valuable characteristics of collection material and breeding stock material of kidney bean (810 specimens) and Russian bean (40 specimens) generated in the Laboratory of Legume Selection and Seed Production, Federal State Budgetary Scientific Institution “Federal Scientific Vegetable Center”. To achieve the goal visual, serological diagnostic methods were used together with biotesting and electron microscopy. The research revealed special physical-chemical characteristics of BYMV Moscow isolates characterized by 100% harmfulness when occurred as co-infection with the other viruses. The main symptoms caused by the above isolates in indicator plants and host plants under conditions of Moscow Region have been described. Evaluation of collection and selection materials of kidney bean and Russian bean formed the basis for identification of the sources of resistance to BYMV exhibiting integrated economically valuable properties (early ripeness, bean shape and color, productivity, etc.). These specimens have been included into selection program of the Federal Research Vegetable Center which is aimed on creation of high-productive varieties of the kidney bean meeting the modern market demands.

scholarly journals Cytospora (Diaporthales) in China

2020 ◽  
Vol 45 (1) ◽  
pp. 1-45 ◽  
Author(s):  
X.L. Fan ◽  
J.D.P. Bezerra ◽  
C.M. Tian ◽  
P.W. Crous
Keyword(s):  
New Species ◽  
Host Plants ◽  
Southwest China ◽  
New Combination ◽  
Large Collection ◽  
Dna Phylogeny ◽  
The Past ◽  
Worldwide Distribution ◽  
Wide Range ◽  
Woody Host

Members of the genus Cytospora are often reported as endophytes, saprobes or phytopathogens, primarily causing canker diseases of woody host plants. They occur on a wide range of hosts and have a worldwide distribution. Although several species have in the past been reported from China, the vast majority are not known from culture or DNA phylogeny. The primary aim of the present study was thus to clarify the taxonomy and phylogeny of a large collection of Cytospora species associated with diverse hosts in China. Cytospora spp. were collected in northeast, northwest, north and southwest China, indicating that the cold and dry environments favour these fungi. In this paper, we provide an assessment of 52 Cytospora spp. in China, focussing on 40 species represented by 88 isolates from 28 host genera. Based on a combination of morphology and a six-locus phylogeny (ITS, LSU, act1, rpb2, tef1-α and tub2), 13 new species and one new combination are introduced. The majority of the species investigated here appear to be host-specific, although further collections and pathogenicity studies will be required to confirm this conclusion.

scholarly journals THE EFFECT OF ILLUMINATION ON STEREO DTM QUALITY: SIMULATIONS IN SUPPORT OF EUROPA EXPLORATION

2016 ◽  
Vol III-4 ◽  
pp. 103-110 ◽  
Author(s):  
R. L. Kirk ◽  
E. Howington-Kraus ◽  
T. M. Hare ◽  
L. Jorda
Keyword(s):  
Horizontal Resolution ◽  
Simulated Image ◽  
Matching Algorithm ◽  
Wide Range ◽  
High Incidence ◽  
Rules Of Thumb ◽  
Image Pairs ◽  
Optimal Quality ◽  
Consistent Support

We have investigated how the quality of stereoscopically measured topography degrades with varying illumination, in particular the ranges of incidence angles and illumination differences over which useful digital topographic models (DTMs) can be recovered. Our approach is to make high-fidelity simulated image pairs of known topography and compare DTMs from stereoanalysis of these images with the input data. Well-known rules of thumb for horizontal resolution (>3–5 pixels) and matching precision (~0.2–0.3 pixels) are generally confirmed, but the best achievable resolution at high incidence angles is ~15 pixels, probably as a result of smoothing internal to the matching algorithm. Single-pass stereo imaging of Europa is likely to yield DTMs of consistent (optimal) quality for all incidence angles ≤85°, and certainly for incidence angles between 40° and 85°. Simulations with pairs of images in which the illumination is not consistent support the utility of shadow tip distance (STD) as a measure of illumination difference, but also suggest new and simpler criteria for evaluating the suitability of stereopairs based on illumination geometry. Our study was motivated by the needs of a mission to Europa, but the approach and (to first order) the results described here are relevant to a wide range of planetary investigations.

scholarly journals Effects of cis-Jasmone Treatment of Brassicas on Interactions With Myzus persicae Aphids and Their Parasitoid Diaeretiella rapae

2021 ◽  
Vol 12 ◽  
Author(s):  
Jamin Ali ◽  
Anca D. Covaci ◽  
Joe M. Roberts ◽  
Islam S. Sobhy ◽  
William D. J. Kirk ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Myzus Persicae ◽  
Methyl Salicylate ◽  
Plant Defence ◽  
Diaeretiella Rapae ◽  
Methyl Isothiocyanate ◽  
Volatile Emission ◽  
Brassica Crops ◽  
Wide Range ◽  
Promising Treatment

There is a need to develop new ways of protecting plants against aphid attack. Here, we investigated the effect of a plant defence activator, cis-jasmone (CJ), in a range of cultivars of Brassica napus, Brassica rapa and Brassica oleracea. Plants were sprayed with cis-jasmone or blank formulation and then tested with peach potato aphids (Myzus persicae Sulzer) (Hemiptera: Aphididae) and their parasitoid Diaeretiella rapae (M'Intosh) (Hymenoptera: Braconidae). CJ treated plants had significantly lower aphid settlement than control plants in a settlement bioassay. Conversely, in a foraging bioassay, D. rapae parasitoids spent a significantly longer time foraging on CJ treated plants. Our results reveal that CJ treatment makes plants less attractive to and less suitable for M. persicae but more attractive to D. rapae in a range of brassica cultivars. It is likely that these effects are due to changes in volatile emission indicating activation of defence and presence of conspecific competitors to aphids but presence of prey to parasitoids. Increases in volatile emission were found in CJ induced plants but varied with genotype. Among the synthetic volatile compounds that were induced in the headspace of CJ treated brassica cultivars, methyl isothiocyanate, methyl salicylate and cis-jasmone were most repellent to aphids. These results build on earlier studies in Arabidopsis and show that tritrophic interactions are influenced by CJ in a wide range of brassica germplasm. The implication is that CJ is a promising treatment that could be used in brassica crops as part of an integrated pest management system.

Determination of Cardinal Temperatures of Flax-leaf Alyssum (Alyssum linifolium) in Response to Salinity, pH, and Drought Stress

Weed Science ◽  
2018 ◽  
Vol 66 (4) ◽  
pp. 470-476 ◽  
Author(s):  
Ahmadreza Mobli ◽  
Ali Ghanbari ◽  
Mehdi Rastgoo
Keyword(s):  
Germination Rate ◽  
Farming Systems ◽  
Quadratic Polynomial ◽  
Polynomial Model ◽  
Weed Species ◽  
Wide Range ◽  
Species Specific ◽  
Cardinal Temperatures ◽  
Different Levels

AbstractFlax-leaf alyssum (Alyssum linifoliumSteph. ex. Willd.) is a winter weed species in irrigated and dryland farming systems of Iran. Experiments were conducted to compare the cardinal temperatures ofA. linifoliumat different levels of drought, salt concentration, and pH. In all experiments, the dent-like model showed a better fit than the quadratic polynomial model.Alyssum linifoliumproduced the highest germination rates at pH 7 and a temperature of 20C in nonstress treatment. Minimum, optimum, and ceiling temperatures in the dent-like model were 4.1 (upper=26.8, lower=10.0) and 35C, and in the quadratic polynomial model were 3.3, 19.1, and 35.0C, respectively. At increased salinity and drought potential levels, the minimum temperature increased, while optimum and ceiling temperatures decreased. Seeds could germinate at up to 20 dS m−1and −1 MPa, respectively, but germination rate and percentage significantly decreased. The seeds of this weed germinated across a wide range of pH values (4≤pH≥8), but the temperature range at which seeds could germinate was reduced. These data serve as guidelines for species-specific propagation protocols and agricultural decision support systems.

The interactive effects of stream temperature, stream size, and non-native species on Yellowstone cutthroat trout

2021 ◽  
Author(s):  
Robert Al-Chokhachy ◽  
Mike Lien ◽  
Bradley B. Shepard ◽  
Brett High
Keyword(s):  
Native Species ◽  
Cutthroat Trout ◽  
Population Level ◽  
Stream Temperature ◽  
Interactive Effects ◽  
Oncorhynchus Clarkii ◽  
Wide Range ◽  
Yellowstone Cutthroat Trout ◽  
Stream Size ◽  
Native Salmonids

Climate change and non-native species are considered two of the biggest threats to native salmonids in North America. We evaluated how non-native salmonids and stream temperature and discharge were associated with Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri) distribution, abundance, and body size, to gain a more complete understanding of the existing threats to native populations. Allopatric Yellowstone cutthroat trout were distributed across a wide range of average August temperatures (3.2 to 17.7ºC), but occurrence significantly declined at colder temperatures (<10 ºC) with increasing numbers of non-natives. At warmer temperatures occurrence remained high, despite sympatry with non-natives. Yellowstone cutthroat trout relative abundance was significantly reduced with increasing abundance of non-natives, with the greatest impacts at colder temperatures. Body sizes of large Yellowstone cutthroat trout (90th percentile) significantly increased with warming temperatures and larger stream size, highlighting the importance of access to these more productive stream segments. Considering multiple population-level attributes demonstrates the complexities of how native salmonids (such as Yellowstone cutthroat trout) are likely to be affected by shifting climates.

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