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The increasing use of recirculating nutrient solutions and drainage water for irrigation purposes requires effective sanitation methods to minimise the dispersal of plant pathogens. Among these, plant viruses are of particular interest because they cannot be cured. A new disinfection system was tested in regard to its ability to inactivate plant viruses in nutrient solution in greenhouses. Potassium hypochlorite produced onsite by an electrolytic disinfector and injected once weekly into the nutrient solution by a sensor, prevented the dispersal of Pepino mosaic virus in the tomato crop. The management program assures that virus particles released from infected plants do not accumulate, forming an infectious virus reservoir which represents an inoculum potential in the hydroponic system. Both tested applications at 0.2 or 0.5 mg free chlorine/l nutrient solution for 60 or 30 min ensured virus inactivation and did not cause phytotoxicity. The yield of tomato plants grown in KCIO-treated nutrient solution was even significantly higher than that of control plants. PepMV-infected source plants solely bore unmarketable tomatoes showing discoloration. By inhibiting the dispersal of PepMV and the infection of test plants, the amount of unmarketable tomato fruits was reduced rigorously in treated variants.
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Irrig Sci (2016) 34:221–229
DOI 10.1007/s00271-016-0500-1
ORIGINAL PAPER
Plant viruses in irrigation water: reduced dispersal of viruses
using sensor‑based disinfection
Martina Bandte1 · Marlon Hans Rodriguez1,2 · Ingo Schuch3 · Uwe Schmidt3 ·
Carmen Buettner1
Received: 28 August 2015 / Accepted: 4 March 2016 / Published online: 17 March 2016
© Springer-Verlag Berlin Heidelberg 2016
infection of test plants, the amount of unmarketable tomato
fruits was reduced rigorously in treated variants.
Introduction
Closed irrigation systems conserve resources and minimise
production costs. However, there is a higher risk of infec-
tious diseases due to improved conditions for the dispersal
of waterborne plant pathogens in the recirculating nutri-
ent solution. A considerable number of virulent pathogens
which are difficult to manage are of significant concern in
greenhouse crops and can cause severe economic losses
(Stewart-Wade 2011). We focused on tomato which yielded
an estimated 14.9 million tons of tomatoes in the EU in
2013 (Eurostat 2015). Although many different fungal,
bacterial and viral pathogens affect tomato plants causing
significant yield losses, we selected Pepino mosaic virus
(PepMV), which has become a major threat to greenhouse
tomato production around the world. It was transferred to
the European and Mediterranean Plant Protection Organi-
zation (EPPO) A2 list in 2012. Pathogens and organisms
listed there are present in the EPPO region but not widely
distributed and are recommended for regulation as quaran-
tine pests. The evidence that PepMV is causing commer-
cial losses is largely based on anecdotal reports. PepMV
was found to reduce the quality of tomato fruits signifi-
cantly, but not the bulk yield (Spence et al. 2006). Losses
correspond to the aggressiveness of the respective PepMV
isolate (Peters et al. 2010). This aggressive isolate caused
an overall yield loss of 4 % and taking into consideration
only class I fruits as much as 14 % loss. In tomato crops
PepMV can be transmitted from plant to plant by mechani-
cal contact (Jones et al. 1980) through contaminated tools,
hands, clothing and direct plant-to-plant contact as well as
Abstract The increasing use of recirculating nutri-
ent solutions and drainage water for irrigation purposes
requires effective sanitation methods to minimise the dis-
persal of plant pathogens. Among these, plant viruses are
of particular interest because they cannot be cured. A new
disinfection system was tested in regard to its ability to
inactivate plant viruses in nutrient solution in greenhouses.
Potassium hypochlorite produced onsite by an electrolytic
disinfector and injected once weekly into the nutrient solu-
tion by a sensor, prevented the dispersal of Pepino mosaic
virus in the tomato crop. The management program assures
that virus particles released from infected plants do not
accumulate, forming an infectious virus reservoir which
represents an inoculum potential in the hydroponic system.
Both tested applications at 0.2 or 0.5 mg free chlorine/l
nutrient solution for 60 or 30 min ensured virus inactivation
and did not cause phytotoxicity. The yield of tomato plants
grown in KCIO-treated nutrient solution was even signifi-
cantly higher than that of control plants. PepMV-infected
source plants solely bore unmarketable tomatoes showing
discoloration. By inhibiting the dispersal of PepMV and the
Communicated by N. Lazarovitch.
* Martina Bandte
martina.bandte@agrar.hu-berlin.de
1 Division Phytomedicine, Faculty of Life Sciences,
Humboldt-Universität zu Berlin, Lentzeallee 55,
14195 Berlin, Germany
2 Agricultural Sciences Faculty – GICAP, Francisco de Paula
Santander University, Cúcuta, Colombia
3 Division Biosystems Engineering, Faculty of Life Sciences,
Humboldt-Universität zu Berlin, Albrecht-Thaer-Weg 3,
14195 Berlin, Germany
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... Detection of the viral pathogens PepMV and TMV in fertigation solution requires concentration of the viruses prior to testing by ELISA [44]. Therefore, samples of 10 l each were concentrated by tangential flow filtration (TFF) with subsequent further concentration of the retentate using ultracentrifugation, as described by Bandte et al. [45]. The pellets were re-suspended and pooled in 300 µL high-purity water and finally tested by ELISA for plant material (see Section 2.1). ...
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... The results obtained on simultaneous contamination with two fungal and two viral pathogens confirm the studies conducted by Rodríguez et al. [47] with the same two fungal pathogens. For complete inactivation of only PepMV a weekly application of 0.2 mg free chlorine/L for 1 h is sufficient [45]. Our previous experiments with the very stable TMV at this dose were not successful (data not shown). ...
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