scholarly journals Probabilistic risk-based model for the assessment of Phyllosticta citricarpa-infected citrus fruit and illicit plant material as pathways for pathogen introduction and establishment

2021 ◽  
Vol 142 ◽  
pp. 105521
Author(s):  
T.R. Gottwald ◽  
E.L. Taylor ◽  
L. Amorim ◽  
A. Bergamin-Filho ◽  
R.B. Bassanezi ◽  
...  
2020 ◽  
Vol 110 (10) ◽  
pp. 1680-1692
Author(s):  
Nga T. Tran ◽  
Andrew K. Miles ◽  
Ralf G. Dietzgen ◽  
Timothy A. Shuey ◽  
Stephen R. Mudge ◽  
...  

Citrus black spot, caused by Phyllosticta citricarpa, is characterized by fruit blemishes and premature fruit drop, resulting in significant economic losses in summer rainfall areas. The pathogen forms both conidia and ascospores during its life cycle. However, the occurrence of these spores and their contributions to infection of fruit in field conditions are not well understood. Our research using direct leaf litter monitoring and volumetric spore trapping in Queensland orchards revealed that pseudothecia and ascospores in leaf litter as well as trapped ascospores had low abundance, while pycnidia and conidia were highly abundant. Both P. citricarpa and endophytic Phyllosticta spp. were identified, with P. citricarpa being dominant. In replicated field trials, we determined that infection of Imperial mandarin fruit by P. citricarpa occurred from fruit set until week 20 of fruit development, with the key infection events taking place between weeks 4 and 16 in Queensland subtropical conditions. These results demonstrate that protecting fruit during weeks 4 to 16 significantly reduced P. citricarpa infection. We found no significant correlation between the disease incidence in fruit and P. citricarpa conidial abundance in leaf litter or ascospore abundance measured by volumetric spore trapping. Therefore, it is suggested that inoculum sources in the tree canopy other than those detected by spore trapping and direct leaf litter monitoring may play a major role in the epidemiology of citrus black spot. Improved knowledge regarding epidemiology of P. citricarpa and an understanding of propagules causing infection may aid in development of more effective disease management strategies.


2016 ◽  
Vol 121 ◽  
pp. 1-8 ◽  
Author(s):  
Pamela Lombardo ◽  
Andrea Guimaraens ◽  
Jorge Franco ◽  
Eduardo Dellacassa ◽  
Elena Pérez Faggiani

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
S. A. M. Perryman ◽  
S. J. Clark ◽  
J. S. West

Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
Y Kobayashi ◽  
H Takemoto ◽  
Z Fu ◽  
E Shimizu ◽  
Y Kinjo

2018 ◽  
Vol 1 (2) ◽  
pp. 17-23
Author(s):  
Takialddin Al Smadi

This survey outlines the use of computer vision in Image and video processing in multidisciplinary applications; either in academia or industry, which are active in this field.The scope of this paper covers the theoretical and practical aspects in image and video processing in addition of computer vision, from essential research to evolution of application.In this paper a various subjects of image processing and computer vision will be demonstrated ,these subjects are spanned from the evolution of mobile augmented reality (MAR) applications, to augmented reality under 3D modeling and real time depth imaging, video processing algorithms will be discussed to get higher depth video compression, beside that in the field of mobile platform an automatic computer vision system for citrus fruit has been implemented ,where the Bayesian classification with Boundary Growing to detect the text in the video scene. Also the paper illustrates the usability of the handed interactive method to the portable projector based on augmented reality.   © 2018 JASET, International Scholars and Researchers Association


2019 ◽  
Vol 25 (1) ◽  
Author(s):  
NARENDRA SINGH ◽  
N. S. BHADAURIA ◽  
PRADYUMN SINGH

The Bio-efficacy of eleven plant extracts namely viz.Neem Kernel; Rhizome of Ginger; Leaves of Datura, Gajarghas, Harsingar, Oak and Latjeera; Bulb of Garlic and Onion; Flowers of Chrysenthemum and Fruits of Chilli in the concentration of 5 percent and imidacloprid @ 40 g ai/ha was tested against mustard aphid, Lipaphiserysimi and their effect on D. rapae and Coccinellid beetle were tested in the Department of Entomology, College of Agriculture, Gwalior (M.P.). All the tested plant materials and imidacloprid @ 40 g ai/ha were effective significanty in reducing the aphid population over control.The aphid population in treated plots ranged from 7.2 to 40.0 as against 85.4 aphid/twig in untreated control. Among the plant material, three sprays of Neem Kernel were found most effective followed by three sprays of chilli fruits.All the plant extracts were found significantly safer to D. rapae and coccinellid bettle in comparision to insecticide (imidacloprid).


Author(s):  
W.M. Williams ◽  
L.B. Anderson ◽  
B.M. Cooper

In evaluations of clover performances on summer-dry Himatangi sandy soil, it was found that none could match lucerne over summer. Emphasis was therefore placed on production in autumn-winter- early spring when lucerne growth was slow. Evaluations of some winter annual clover species suggested that Trifolium spumosum, T. pallidum, T. resupinatum, and T. vesiculosum would justify further investigation, along with T. subterraneum which is already used in pastures on this soil type. Among the perennial clover species, Kenya white clover (7'. semipilosum) showed outstanding recovery from drought and was the only species to produce significantly in autumn. However, it failed to grow in winter-early spring. Within red clover, materials of New Zealand x Moroccan origin substantially outproduced the commercial cultivars. Within white clover, material from Israel, Italy and Lebanon, as well as progeny of a selected New Zealand plant, showed more rapid recovery from drought stress and subsequently better winter growth than New Zealand commercial material ('Grasslands Huia'). The wider use of plant material of Mediterranean origin and of plants collected in New Zealand dryland pastures is advocated in development of clover cultivars for New Zealand dryland situations.


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