Basin water is generally mixed with drain water untreated, i.e. without disinfection; all pathogens in the basin are sent directly into the greenhouse. Robert de Hoo and Kees Luykx, distributor and producer of USAF ultrasonic transmitters, are amazed by this.
Robert: "We can actually say that there is often no insight into the quality of the basin water used. The drain water is almost always disinfected, but that is hardly ever done for basin water."
He points to practical examples. "Recently, the Tomato brown rugose fruit virus (ToBRFV) was found in the basin water of a tomato grower in Belgium, while the virus had not (yet) been found in the greenhouse, and at a grower in West-Friesland, a very strong concentration of the Pythium fungus was found in a fully covered basin (against algae growth). In both cases, the water was pumped directly into the mixing containers without any form of disinfection. Both growers found out about these infections by accident. If they had used this contaminated water in the greenhouses, this could obviously have resulted in a lot of extra work and large damage costs."
USAF ultrasonic transmitters
Both companies contacted Ultramins in response to previous articles on GroentenNieuws. Ultramins is the exclusive distributor of the USAF ultrasonic transmitters that combat micro-organisms in basin and silo water.
Robert: "We were asked whether our USAF ultrasonic transmitters could offer a solution, and, of course, they can. However, we are surprised by the fact that growers are still prepared to use basin water at their own discretion. Various strict and expensive measures are taken to work as safely as possible. For instance, no visitors are allowed in the greenhouse, shoes are disinfected, protective clothing is worn and tools are often disinfected. Laboratories can easily tell what is in the basin water from the water samples, so you are not going to take any risks with that, are you?
"However, even if you know the result, it can be different tomorrow as basin water is an open system. Basin water can be disinfected in a relatively simple way and in combination with H2O2 USAF, which kills off more than 99.99% of the micro-organisms. These transmitters work 24/7 at low operational costs, require no maintenance, are environmentally friendly, and deliver the best results."
Testing
Tests with ToBRFV-contaminated water, recently done by Proeftuin Ron Peters, showed that virus in the water causes contamination of the plants. (Read the article about the test here (NL)). These are risks growers should not take, according to Robert. "However, people often still think in a traditional way: 'This is how we have always done it, we have never disinfected the basin water before'. While in fact, every grower knows that there are enough dangers lurking in this water stream, especially when other growers or arable farmers are active in the vicinity."
Kees Luijkx, USAF producer: "We know for sure that, when all the water is disinfected by USAF, yields will improve and failures will decrease. Every grower knows that cleaner cultivation water leads to higher yields. It is therefore surprising that risks are still being taken with basin and cultivation water. The risks that are currently being taken can easily lead to enormous losses, which could easily have been prevented. Suppose that this method of disinfection brings with it an extra yield of only 1 to 2% - then any investment is quickly recouped."
For more information:
Robert de Hoo 
Ultramins B.V.
Jelle Zijlstraweg 45
1689 ZX Zwaag
+31 (0) 620 536 536
+31(0) 85 023 10 97
[email protected]
www.ultramins.com