scholarly journals Diversity ofPhytophthora,Pythium,and PhytopythiumSpecies in Recycled Irrigation Water in a Container Nursery

2019 ◽  
Vol 3 (1) ◽  
pp. 31-45 ◽  
Author(s):  
Neelam R. Redekar ◽  
Joyce L. Eberhart ◽  
Jennifer L. Parke

Recycling of irrigation water increases disease risks due to spread of waterborne oomycete plant pathogens such as Phytophthora, Pythium, and Phytopythium. A comprehensive metabarcoding study was conducted to determine spatial and temporal dynamics of oomycete communities present in irrigation water collected from a creek (main water source), a pond, retention reservoirs, a chlorinated water reservoir, and runoff channels within a commercial container nursery in Oregon over the course of 1 year. Two methods, filtration and leaf baiting, were compared for the detection of oomycete communities. Oomycete communities in recycled irrigation water were less diverse but highly enriched with biologically active plant pathogens as compared with the creek water. The filtration method captured a larger portion of oomycete diversity, while leaf baiting was more selective for plant-associated oomycete species of Phytophthora and a few Pythium and Phytopythium species. Seasonality strongly influenced oomycete diversity in irrigation water and detection with leaf baiting. Phytophthora was the major colonizer of leaf baits in winter, while all three genera were equally abundant on leaf baits in summer. The metabarcoding approach was highly effective in studying oomycete ecology, however, it failed to distinguish some closely related species. We developed a custom oomycete internal transcribed spacer (ITS)1 reference database containing shorter sequences flanked by ITS6 and ITS7 primers used in metabarcoding and used it to assemble a list of indistinguishable species complexes and clusters to improve identification. The predominant bait-colonizing species detected in recycled irrigation water were the Phytophthora citricola-complex, Phytophthora syringae, Phytophthora parsiana-cluster, Phytophthora chlamydospora, Phytophthora gonapodyides, Phytophthora irrigata, Phytophthora taxon Oaksoil-cluster, Phytophthora citrophthora-cluster, Phytophthora megasperma-cluster, Pythium chondricola-complex, Pythium dissotocum-cluster, and Phytopythium litorale.

Author(s):  
Rumiana Kireva ◽  
Roumen Gadjev

The deficit of the irrigation water requires irrigation technologies with more efficient water use. For cucumbers, the most suitable is the drip irrigation technology. For establishing of the appropriate irrigation schedule of cucumbers under the soil and climate conditions in the village of Chelopechene, near Sofia city, the researchеs was conducted with drip irrigation technology, adopting varying irrigation schedules and hydraulic regimes - from fully meeting the daily crops water requirements cucumbers to reduced depths with 20% and 40%. It have been established irrigation schedule with adequate pressure flows in the water source, irrigation water productivity and yields of in plastic unheated greenhouses of the Sofia plant.


Author(s):  
P. Bykova ◽  
I. Egorova ◽  
A. Strelkov ◽  
L. Talovyria ◽  
O. Nesterenko ◽  
...  

При изучении качества воды источника водоснабжения г. Самары Саратовского водохранилища особое внимание было уделено основным показателям, влияющим на выбор реагентной обработки: мутность, перманганатная окисляемость и цветность. Сезонные изменения качества воды водохранилища требуют постоянной корректировки дозы реагентов с целью достижения нормативных требований к качеству очищенной воды. Приводятся результаты производственных исследований изменения качества воды Саратовского водохранилища в створе водозаборов г. Самары за 20172019 годы по мутности, перманганатной окисляемости и цветности. В связи с аномальными температурными перепадами и наступлением осеннего паводка (конец декабря 2019 г. и январь 2020 г.) резко изменилось качество воды водохранилища по цветности и перманганатной окисляемости. Отмечено, что увеличение указанных показателей потребовало повышения дозы реагентов при очистке исходной воды. Оптимальная доза реагентов постоянно коректируется в зависимости от состава исходной воды на флокуляторе Lovibond ЕТ-750 . Регулярное проведение пробного коагулирования позволило поддерживать качество очищенной воды в соответствии с нормативными требованиями СанПиН 2.1.4.1074-01 Питьевая вода. Контроль качества , кроме цветности и железа общего, так как превышение этих показателей наблюдалось в пределах погрешности методов измерения.While studying the water quality of the water source of the city of Samara the Saratov water reservoir, special attention was paid to the main indicators that influence the choice of chemical treatment: turbidity, permanganate index and color. Seasonal changes in the water quality of the water reservoir require constant adjustment of the chemical dose in order to meet the regulatory requirements to the quality of treated water. The results of the studies of changes in the water quality of the Saratov reservoir at the water abstraction points of the city of Samara for 20172019 by turbidity, permanganate index and color are presented. Due to the abnormal temperature differences and onset of autumn flood (end of December 2019 and January 2020), the water quality in the water reservoir dramatically changed in color and permanganate index. It was noted that an increase in these indicators required an increase in the dose of chemicals during the source water purification. The optimal dose of chemicals is selected with Lovibond ET-750 flocculator depending on the composition of the source water. Regular test coagulation allowed maintaining the quality of purified water in accordance with the regulatory requirements of SanPiN 2.1.4.1074-01 Drinking water. Quality control , except for color and total iron since the values of these indicators were increased within the measurement accuracy.


Author(s):  
M. V. Dlamini ◽  
M. T. Masarirambi

Saline irrigation water is becoming an important water source as fresh water is fast becoming a scarce resource in many areas of the world, including Eswatini, especially in arid and semi-arid regions.  A study to test the response of two varieties of spinach (fordhook giant and mustard) to salinity was conducted in a field pot experiment at the Faculty of Agriculture at the Luyengo Campus of the University of Eswatini.  The treatments were laid in a randomized block design (RCBD).  The experiment consisted of four treatments, each replicated twelve times.  Treatments were salinity levels of 0.0 dS/m, 1.5 dS/m, 2.0 dS/m and 3.5 dS/m.  All the treatments were subjected to similar agronomic practices. Spinach was grown and observed for a period of five weeks.  Plant height was measured and the number of leaves counted weekly throughout the experiment. Significant differences (P < 0.05) between salinity treatments were obtained for plant height beginning in week 2 but were more pronounced in week 3, 4 and week 5.  No significant differences were obtained for the number of leaves.  There were however, clear significant differences between spinach irrigated with none saline irrigation water compared to saline irrigation water.   It was concluded that irrigating spinach with saline water of more than 2.0 dS/m drastically reduce plant growth but not the number of leaves under the conditions of the experiment.


Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 459 ◽  
Author(s):  
Adas Marčiulynas ◽  
Diana Marčiulynienė ◽  
Jūratė Lynikienė ◽  
Artūras Gedminas ◽  
Miglė Vaičiukynė ◽  
...  

The aim of the present study was to assess fungal and oomycete communities in the irrigation water of forest nurseries, focusing on plant pathogens in the hope of getting a better understanding of potential pathogenic microorganisms and spreading routes in forest nurseries. The study sites were at Anykščiai, Dubrava, Kretinga and Trakai state forest nurseries in Lithuania. For the collection of microbial samples, at each nursery five 100-L water samples were collected from the irrigation ponds and filtered. Following DNA isolation from the irrigation water filtrate samples, these were individually amplified using ITS rDNA as a marker and subjected to PacBio high-throughput sequencing. Clustering in the SCATA pipeline and the taxonomic classification of 24,006 high-quality reads showed the presence of 1286 non-singleton taxa. Among those, 895 were representing fungi and oomycetes. The detected fungi were 57.3% Ascomycota, 38.1% Basidiomycota, 3.1% Chytridiomycota, 0.8% Mucoromycota and 0.7% Oomycota. The most common fungi were Malassezia restricta E. Guého, J. Guillot & Midgley (20.1% of all high-quality fungal sequences), Pezizella discreta (P. Karst.) Dennis (10.8%) and Epicoccum nigrum Link (4.9%). The most common oomycetes were Phytopythium cf. citrinum (B. Paul) Abad, de Cock, Bala, Robideau, Lodhi & Lévesque (0.4%), Phytophthora gallica T. Jung & J. Nechwatal (0.05%) and Peronospora sp. 4248_322 (0.05%). The results demonstrated that the irrigation water used by forest nurseries was inhabited by a species-rich but largely site-specific communities of fungi. Plant pathogens were relatively rare, but, under suitable conditions, these can develop rapidly, spread efficiently through the irrigation system and be a threat to the production of high-quality tree seedlings.


Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2558 ◽  
Author(s):  
Andrew Ristvey ◽  
Bruk Belayneh ◽  
John Lea-Cox

Water security in ornamental plant production systems is vital for maintaining profitability. Expensive, complicated, or potentially dangerous treatment systems, together with skilled labor, is often necessary to ensure water quality and plant health. Two contrasting commercial ornamental crop production systems in a mesic region are compared, providing insight into the various strategies employed using irrigation-water containment and treatment systems. The first is a greenhouse/outdoor container operation which grows annual ornamental plants throughout the year using irrigation booms, drip emitters, and/or ebb and flow systems depending on the crop, container size, and/or stage of growth. The operation contains and recycles 50–75% of applied water through a system of underground cisterns, using a recycling reservoir and a newly constructed 0.25 ha slow-sand filtration (SSF) unit. Groundwater provides additional water when needed. Water quantity is not a problem in this operation, but disease and water quality issues, including agrochemicals, are of potential concern. The second is a perennial-plant nursery which propagates cuttings and produces field-grown trees and containerized plants. It has a series of containment/recycling reservoirs that capture rainwater and irrigation return water, together with wells of limited output. Water quantity is a more important issue for this nursery, but poor water quality has had some negative economic effects. Irrigation return water is filtered and sanitized with chlorine gas before being applied to plants via overhead and micro-irrigation systems. The agrochemical paclobutrazol was monitored for one year in the first operation and plant pathogens were qualified and quantified over two seasons for both production systems. The two operations employ very different water treatment systems based on their access to water, growing methods, land topography, and capital investment. Each operation has experienced different water quantity and quality vulnerabilities, and has addressed these threats using a variety of technologies and management techniques to reduce their impacts.


2020 ◽  
Vol 96 (11) ◽  
Author(s):  
Mathilde Borg Dahl ◽  
Matthias Krebs ◽  
Martin Unterseher ◽  
Tim Urich ◽  
Greta Gaudig

ABSTRACT The drainage of peatlands for their agricultural use leads to huge emissions of greenhouse gases. One sustainable alternative is the cultivation of peat mosses after rewetting (‘Sphagnum farming’). Environmental parameters of such artificial systems may differ from those of natural Sphagnum ecosystems which host a rich fungal community. We studied the fungal community at a 4 ha Sphagnum farming field site in Northwestern Germany and compared it with that of natural Sphagnum ecosystems. Additionally, we asked if any fungi occur with potentially negative consequences for the commercial production and/or use of Sphagnum biomass. Samples were collected every 3 months within 1 year. High-throughput sequencing of the fungal ITS2 barcode was used to obtain a comprehensive community profile of the fungi. The dominant taxa in the fungal community of the Sphagnum farming field site were all commonly reported from natural Sphagnum ecosystems. While the taxonomic composition showed clear differences between seasons, a stable functional community profile was identified across seasons. Additionally, nutrient supply seems to affect composition of fungal community. Despite a rather high abundance of bryophyte parasites, and the occurrence of both Sphagnum-species-specific and general plant pathogens, their impact on the productivity and usage of Sphagnum biomass as raw material for growing media was considered to be low.


2011 ◽  
Vol 48 (1) ◽  
pp. 99-110 ◽  
Author(s):  
AJAY SINGH ◽  
SUDHINDRA NATH PANDA

SUMMARYThe groundwater in some parts of north India is generally saline and not suitable for drinking. However, it can be used for growing salt-tolerant crop plants. To explore the potential of using saline groundwater for farm production, a field experiment was conducted at Shahpur village, near Hisar in Haryana State, India, to study the effect of different qualities of irrigation water on mustard (Brassica juncea, cv. RH–30) crop growth, yield, water use efficiency and soil salinity. Treatments consisted of combinations of irrigation with saline groundwater (electrical conductivity (EC) 7.48 dS m−1), and a good quality canal water (EC 0.4 dS m−1) applied either alone, as blends or in alternate applications. In all treatments, canal water was used for pre-sowing irrigation. In mustard cultivation, saline groundwater with an EC of 7.48 dS m−1 can be used safely to supplement all post-sowing irrigations with marginal decline in crop yield. Irrigation with saline groundwater gave a yield as high as 95% of the optimum crop yield obtained with fresh canal water. The temporal variation in salinity showed that mustard yield responds to the average salinity of the soil during the growing season. Thus saline groundwater is a good water source to exploit for supplemental irrigation.


2018 ◽  
Vol 39 (1) ◽  
pp. 109-117
Author(s):  
Ikram Mokeddem ◽  
Meriem Belhachemi ◽  
Touhami Merzougui ◽  
Noria Nabbou ◽  
Salih Lachache

AbstractGroundwater samples from Turonian aquifer of Béchar region were evaluated as drinking and irrigation water sources. physicochemical parameters including pH, EC, TH, Na+, Ca2+, Mg2+, Cl−, SO42– and NO3− were determined for 16 water sampling points. These characterizations show that the groundwater is fresh to brackish, slightly alkaline and the major ions are Na+, Ca2+, Mg2+, Cl− and SO42–. According to WHO standards, 50% of the analysed water are suitable as a drinking source while the other samples are not in compliance with drinking water standards. This non-compliance is basically due to the high concentrations of Na+, Cl−, and SO42– requesting further treatment to reach the stringent standards. According to the results of nitrate concentrations, anthropogenic source seems to influence the groundwater quality. The present study shows that Béchar groundwater may represent an important drinking and irrigation water source. However, a specific management strategy should be adapted in order to avoid the contamination by anthropogenic sources.


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