scholarly journals Efficacy of fungicides against brown spot on walnuts in the Western Forest-Steppe of Ukraine

Author(s):  
A. Skoreyko ◽  
T. Andriychuk ◽  
R. Bilyk

Goal. To study the effectiveness of fungicides against brown spot of walnut in the Western Forest-Steppe of Ukraine. Methods. The studies were carried out during 2018—2019. in agrocenoses of the walnut garden of the Ukrainian Research Station of Plant Quarantine of the Institute of Plant Protection of the NAAS. At the detailed account inspected not less than 3—4 accounting trees from four parties of a crown and analyzed on 25 accounting bodies (leaves, shoots, fruits) and determined intensity of defeat. The study of the effectiveness of fungicides against brown spot was carried out on the nut variety Bukovynsky 2 using drugs: Bordeaux liquid, 1-percent solution — the standard; Kuproksat, s. c., (copper sulphate tribasic, 345 g/l), Medyan Extra 350 SC s. c., (copper chloride, 350 g/l). Results. Defeat of leaves at the last account in variants with the drug Medyan Extra 350 SC s. c., decreased in comparison with control in 2.6 times, development of a disease — in 2.8 times. By all indicators, the variant with the drug Kuproksat, hp was more effective, where the brown leaf spot was 20.5% (64.5% in the control), the disease was 9.3% (31.4% in the control). Fetal damage in the last account in the experimental variants was respectively 2.7—3.9 times less, and the development of the disease — 3.1—4.2 times weaker than in the control. Conclusions. The obtained data show that in the conditions of the western Forest-Steppe of Ukraine the application of fungicides on walnut both in the experimental and in the reference variants provided good and approximately identical protection of the nut against brown spot Ophiognomonia leptostyla (Fr.) Sogonov. The effectiveness of fungicides was the highest in the variant with the drug Kuproksat, hp, (on the leaves — 70.4%, on the fruits — 75.9%). Technical efficiency of the drug Medyan Extra 350 SC, s. c. on leaves and fruits was 64.6 and 67.9%, respectively. Fungicide treatment of experimental plots helps to reduce the incidence of the disease, which makes it possible to obtain a yield of 0.9—1.1 t/ha higher than in the control.

2020 ◽  
Vol 20 (1) ◽  
pp. 13-18
Author(s):  
I Gede Swibawa ◽  
Franciscus Xaverius Susilo ◽  
Purnomo Purnomo ◽  
Titik Nur Aeny ◽  
Setyo Dwi Utomo ◽  
...  

Infestation of major pests and diseases on various cassava clones in Lampung-Indonesia. Lampung Province is one ofcassava producers in Indonesia which contributes more than 30% to the total national cassava production. However, theinfestation of pests and diseases can limit cassava production in the field. The objective of this research was to observe theinfestation level of major plant pests and diseases of cassava in Lampung. A survey was conducted in August 2016 in severallocations of cassava fields owned by farmers and experimental plots in the area of Faculty of Agriculture, University ofLampung. The results showed that cassava mealybug (Phenacoccus manihoti), papaya mealybug (Paracoccus marginatus)and red mite (Tetranychus urticae) infested at cassava clones in Lampung. The infestation of red mite tended to be higher thanthat of mealybugs. The cassava brown leaf spot disease that infested in mild to moderate severity was found on all cassavaclones, while viral disease with prevalence of 78% was only found on Duwet 1 clone in experimental plot.


Plant Disease ◽  
2021 ◽  
Author(s):  
Chunlin Yang ◽  
Yu Deng ◽  
Feihu Wang ◽  
Hanbo Yang ◽  
Xiulan Xu ◽  
...  

Juglans sigillata Dode (Iron walnut) is mostly distributed in southwestern China, and valued for wood and nuts (Feng et al. 2018). In April 2020, we surveyed a walnut garden located in Baisha Town, Wanyuan City, (Sichuan, China), where brown spot symptoms were observed on leaves of ten trees among of 100 plants, and this disease can result in a reduced growth potential when trees are severely infected. Necrotic and subcircular lesions with conidiamata were observed on diseased leaves. Symptomatic leaves were collected and taken back to the laboratory forfurther analysis. Using the single spore isolation technique developed by Chomnunti et al. (2014), five isolates were grown from the infected leaves on Potato Dextrose Agar medium (PDA). The five isolates had similar colony morphology, which was initially white, suborbicular, gradually turning yellowish with black spots, developing fluffy aerial mycelium. Morphological characteristics were examined using light microscopy on the PDA. Conidiogenous cells were subcylindrical to cylindrical, or ampulliform, hyaline, rarely branched. Macroconidia were lunate, reniform, hyaline, 1-3-septate, mostly 1-septate, distinctly constricted at the septum, the basal cell was bluntly rounded, the apical cell had an acute end, and the basal cell was equal to or larger than the apical cell, measuring 22 to 40.5 × 2.5 to 8.3 μm (mean = 32 × 6.2 μm, n = 50). Microconidia were botuliform, or subfusiform, hyaline, both ends were rounded, straight or curved, aseptate, and measured 10 to 28.5 × 1.9 to 3.7 μm (mean= 17.2 × 2.7 μm, n = 20). A multilocus approach was conducted for precise identification of a representative isolate SICAUCC 20-0012. The internal transcribed spacer regions (ITS), guanine nucleotide-binding protein subunit beta gene (MS204), and translation elongation factor 1-alpha (tef1-α) of isolate SICAUCC 20-0012 were amplified and sequenced as described by Sogonov et al. (2008) and Walker et al. (2012a). GenBank Accession Nos. for ITS, MS204, and tef1-α are MW250303, MW246773, and MW246775, respectively. Phylogenetic analyses showed 100% support with Ophiognomonia leptostyla (Fr.) Sogonov, and the morphology was consistent with the asexual stage of O. leptostyla documented by Walker et al. (2012b). To test Koch’s postulates, five healthy plants of J. sigillata (2- to 3-year-old) with 5-8 leaves per plant were inoculated with conidial suspensions (104 conidia/mL) after wounded with a small pin as described by Desai et al. (2019), and the same number of healthy plants were wounded and sprayed with sterile distilled water as controls. Plants were sprayed regularly with distilled water every day and placed in a growth chamber at 25℃ with a 12-h fluorescent light/dark regimen. After 15 days, typical brown spot symptoms developed on inoculated leaves, but not on the controls. The fungus O. leptostyla was reisolated from the lesion as described above but not from non-inoculated leaves. O. leptostyla has been reported on some walnut trees; for example: J. ailantifolia, J. californica, J. cinerea, J. hindsii, J. major, J. mandshurica, J. nigra, and J. regia (Farr & Rossman 2020). However, to our knowledge, this is the first report of O. leptostyla causing brown leaf spot on J. sigillata. J. sigillata is an economically important tree in southwest China, and fungicide treatments should be considered to prevent the spread of this fungus before it becomes more widespread. Chunlin Yang, Yu Deng, and Feihu Wang contributed equally to this work. This research was supported by the Key Research and Development Project of Sichuan Province (2021YFYZ0032)


2021 ◽  
Vol 21 (2) ◽  
Author(s):  
V.K. Soni ◽  
Ranjeeta Nag

The investigation on “Pathogenic disease occurrence in plantation sites of Bastar district, CG, India” revealed that the several disease of Tectona grandish and Eucalyptus globules trees species in the plantation site maintained by Bastar forest division (C.G.) During the survey of plantation sites, many trees were infected by pathogens. The infected teak species showed leaf spot, leaf blight, leaf gull, leaf brown spot, stem canker, powdery mildew etc. and affecting the growth and form of teak. Whereas in Eucalyptus trees showed stem canker, collar rot, leaf spot, leaf rust, brown leaf spot, disease and affecting the growth and forms of Eucalyptus. The survey was conducted at two plantation sites namely Titrgaon and Bastar in the region and incidence of pathogenic disease commonly found and casual organism/ pathogen were identified prescribed disease management was recorded. Management of immediate removal of infected plants helps to prevent the disease spread. Therefore, the present investigation was carried out for knowing occurrence and abundance of pathogens associated with Teak and Eucalyptus trees plantation in the Bastar district of Chhattisgarh.


Plant Disease ◽  
1998 ◽  
Vol 82 (11) ◽  
pp. 1282-1282 ◽  
Author(s):  
A. K. M. Shahjahan ◽  
M. C. Rush ◽  
J. P. Jones ◽  
D. E. Groth

White leaf streak, caused by Mycovellosiella oryzae (Deighton and Shaw) Deighton (syn. Ramularia oryzae), was found in Louisiana rice. The symptoms closely resemble those of narrow brown leaf spot caused by Cercospora janseana (Racib.) O. Const. (syn. C. oryzae (Miyake)), and it is difficult to distinguish between these two diseases. Initially both produce similar elongated light brown lesions, but later the lesions of white leaf streak become wider with a whitish center and are surrounded by a narrow light brown margin (2,3). The disease was first observed at the Rice Research Station, Crowley, LA, in 1996 on older leaves of the cultivar Lemont at maturity. Leaves containing the unusual lesion types were placed in a moist chamber and incubated at 28°C for 5 days. Abundant conidia were produced and the fungus was isolated on acidified potato dextrose agar (APDA) by single spore isolation and by plating infected tissues after surface sterilization in 40% Clorox for 10 to 15 min. The colonies grew slowly on APDA and were dark gray in color. The conidia formed in branched chains or singly. They were hyaline, cylindrical with tapering ends and a thick hilum; 0 to 3 septate, and 15 to 35 m long (1,3). Pathogenicity tests were conducted in the greenhouse on the Lemont and Cypress rice cultivars by spraying a conidial suspension (103–4 conidia per ml) onto leaf blades at boot stage. Conidia were produced by growing the fungus on PDA for 10 to 14 days. Inoculated plants were placed inside a humid chamber in a greenhouse and maintained for 4 to 5 weeks. Many elongated lesions similar to those observed in the field were produced 3 to 4 weeks after inoculation. Reisolation from these lesions yielded M. oryzae. With the same methods, 45 cultivars and lines were inoculated to determine their reactions to this disease. Most of the cultivars grown in the southern United States were moderately susceptible or susceptible to white leaf streak. Foreign cultivars tested, including BR-7, BR-11, Cica-4, Cica-6, Cica-7. Cica-8, Cica-9, Oryzica llanos, Rax clear, Teqing, and Tetep, were resistant. In 1997, the disease was found prevalent on many cultivars grown at the Rice Research Station, Crowley, LA. As symptoms of both white leaf streak and narrow brown leaf spot were sometimes observed on the same leaf; it is possible that the disease has been present, but not identified as a separate disease because of the similarity of the symptoms of the two diseases. A thorough survey is necessary to determine the extent of its occurrence and further studies are necessary to determine its yield loss potential. At present it appears to be a minor problem for Louisiana rice. White leaf streak has previously been recorded from Papua New Guinea on cultivated Oryza sativa, and from the Solomon Islands, Sabah, Nizeria, and Sierra Leone on cultivated O. glabberima Steudel and on wild perennial rice O. berthii A. Chev. (2). This is the first report of white leaf streak on cultivated rice in the United States. References: (1) F. C. Deighton. Mycol. Pap., CMI 144:1,1979. (2) F. C. Deighton and D. Shaw. Trans. Br. Mycol. Soc. 43: 515, 1960. (3) B. C. Sutton and A. K. M. Shahjahan. Nova Hedwigia 25:197, 1981.


Crop Science ◽  
1986 ◽  
Vol 26 (3) ◽  
pp. 533-536 ◽  
Author(s):  
Clyde C. Berg ◽  
Robert T. Sherwood ◽  
Kenneth E. Zeiders

Plant Disease ◽  
2019 ◽  
Vol 103 (5) ◽  
pp. 1038 ◽  
Author(s):  
T. E. Kaspary ◽  
C. Bellé ◽  
C. A. G. Rigon ◽  
L. Cutti ◽  
G. Casarotto ◽  
...  

2021 ◽  
Vol 285 ◽  
pp. 02027
Author(s):  
O. Yu. Kremneva ◽  
K. E. Gasiyan ◽  
A. V. Ponomarev ◽  
A. Kokhmetova ◽  
S. I. Novoseletsky

To carry out effective plant protection measures, it is necessary to take into account all the factors affecting the quality of the crop. The aim of our research was to study the degree of development of leaf diseases of winter wheat and the rate of infestation of crops, depending on the tillage method. The studies were carried out in 2019-2020 at the experimental plots of “Kuban educational farm” in Krasnodar. For the research, four experimental plots with Steppe variety of soft winter wheat were created, where various soil cultivation systems were applied: 1 - No-Till (zero technology), 2 - moldboard-free technology, 3 - recommended, 4 - moldboard technology. The article presents data on the degree of development of diseases and the degree of infestation of winter wheat plants in the crops of test plots with various tillage systems. It was found that the most preferable is the use of the recommended type of treatment, since with it the least number of diseases develops and the degree of development of pathogens is reduced by 2-3 times in comparison with other options. The influence of the tillage method on the number and composition of phytopathogen spores was revealed.


2020 ◽  
pp. 61-66
Author(s):  
О. Yu. Kremneva ◽  
I. A. Kostenko ◽  
A. A. Pachkin ◽  
R. Yu. Danilov ◽  
A. V. Ponomarev ◽  
...  

There have been carried out the route surveys to assess the development and distribution of the main pathogens of wheat and barley in 57 districts ofKrasnodar,StavropolTerritoriesand Rostov Region. The collection, organization and analysis of information on the damage degree of the production and breeding sowings of these grain crops by the main pathogens was conducted using a single spatial information environment designed by the Russian company “NextGIS”. During the field surveys, there have been included the data on the resistance to causative agents of yellow leaf spot of wheat, wheat Septoria leaf spot, powdery mildew on wheat and barley, rust diseases on wheat and barley, net spot of barley, and brown spot of barley into the program. In addition, while filling in the survey card, there were taken into account the date and time of the assessment, the phase of development of the grain crop, the variety; there was carried out a photographic fixation of the examined plants. In the field, there was used the freely distributed NextGIS Mobile software, installed on mobile digital devices (smartphones) running by the Android operating system. According to the results of field surveys using the NextGIS QGIS full-featured desktop geographic information system there were prepared thematic cartographic materials of the main wheat and barley pathogens in the southern region ofRussia. The collected long-term data of phytosanitary surveys will allow conducting a temporary analysis of the spatial distribution of pathogens in the studied area. This information can be useful for specialists dealing with plant protection, for employees of breeding institutions who develop varieties resistant to economically significant diseases of grain crops. The data can be used also by a wide range of specialists engaged in plant breeding who conduct field surveys and account any parameters of plant conditions, harmful facilities and the environment, as well as by the consumers of such information.


Author(s):  
A. P. Voloshchuk ◽  
I. S. Voloshchuk ◽  
V. V. Gliva ◽  
O. M. Sluchak ◽  
G. S. Gereshko ◽  
...  

In recent years, interest in non-traditional methods of farming and plant growing has increased, which include the widespread use of biological methods of plant protection and nutrition, allowing significantly reduce the use of pesticides and reduce fertilizer rates. Therefore, there is a constant search and selection of highly effective and competitive formulations that, in growing technologies, ensured an increase in yield and the quality of the grown products. It has been established that the reasons for obtaining seeds of low yielding and sowing qualities of winter wheat in the zone of excessive moisture in the Western Forest-Steppe of Ukraine are lodging of crops and the development of harmful diseases. These negative phenomena can be prevented through the use of the Vympel-2 growth regulator and Oracle microfertilizer colofermin copper, both when separately and simultaneously introduced into the ejection phase of the tube. Under the influence of these formulations, resistance to lodging of plants increases, the spread of diseases decreases: powdery mildew, leaf septoria, and dark brown rust. The increased spike growth and the best filling of winter wheat grains occur due to the shortening of the vegetative part of the shoot, which contributes to a significant increase in productivity - 0.45–0.55 t / ha. Due to optimal growth and development, seeds of high sowing qualities are formed on maternal plants. The most effective is the tank mixture of the Vympel-2 growth regulator (0.5 l / ha) with microfertilizer Oracle colofermin copper (1.0 l / ha) against the background of N30P90K90 with the phased introduction of nitrogen according to N30P90K90 at the IV and VII stages of organogenesis, which reduced development diseases on plants compared with the control (without treatment of sowing) by 15.4% (powdery mildew), 10.8 (leaf Septoria) and 10.4% (dark brown spotting).


Sign in / Sign up

Export Citation Format

Share Document