Tholen – Since last summer, a test kit has been on the market with which growers can quickly, easily and everywhere detect the presence of the Tomato brown rugose fruit virus (ToBRFV) in a pre-symptomatic phase. However, the virus does not only appear in plants. That is why producer Spark Radar has made efforts to expand the testing options. In addition to the existing tests for ToBRFV, a test for the cucumber mottled virus (CGMMV) has also been added to the range.
Building on the ToBRFV test for leaf material, there is now also a test to check seeds, water and surfaces for the presence of the virus. Rogier van der Voort, co-founder of the company, announced those tests at the end of last year.
The hardware that Spark Radar supplies and that the growers use to perform the test is the same for every test variant. This means that growers do not have to make an extra investment to want to use a different test method, such as water or surfaces. The first actions for the water test are different (collecting and filtering water is different from pipetting juices from leaf material), but the rest of the principle works the same.
The standard hardware to perform the test is also the same for the new tests. Spark Radar developed a magnetic rack and a detection rack. By using the magnetic rack, the tester, as it were, pulls the virus out of the sample. “It contributes to the high sensitivity of our test. Even in the presence of a low virus load, the test will detect the virus.”
An important caveat when using the rapid PCR test is that the result of the test does not provide any information about whether the virus found is dead or alive. “No test has been able to do that so far. You really need to do a biotest for this,” says Rogier. The fact is that growers want to test quickly and that Spark Radar’s test makes this possible, also faster than testing via a laboratory.
Locate and contain virus
The demand from growers for the tests is high. They use the tests to check whether the virus is present after cleaning the greenhouse after cultivation, for example with water samples, but also frequently to keep control and limit the damage, according to the experience of Rogier and his partner Bas Rutjens. . “As long as the virus is still fully present, there is a need for a solution that can detect the virus in a pre-symptomatic stage.”
Growers try to learn how to work with the virus as best they can. “They use our tests to locate the virus and use that knowledge to contain the virus as best as possible.”
Testing seeds for ToBRFV
Also new is a test for seeds. Following a concrete request from a breeder in Italy, Spark Radar has also developed a test for seeds in recent months. A maximum of 500 seeds can be tested in it at the same time. “The procedure for testing seeds is slightly different than for leaf material. To detect the presence of the virus in seeds, extra time is needed to remove the virus from the seeds. The material must be in the buffer extraction bag that we supply for 12 hours before the test can be carried out,” says Rogier. “In this way, the existing hardware can then be used to extract the virus from the sample, as it were.”
The demand for ToBRFV testing is certainly not only Dutch, although based on official figures, the number of infections seems to be greatest there. According to the most recent official NVWA figures, the Netherlands has fifty of them. However, the virus is also present in other countries and the international spread continues.
At Spark Rader, in addition to the Netherlands, they have already delivered tests to the necessary well-known tomato growing areas in Europe, such as Belgium, France and Italy, but also in the United States and Canada. “In North America, the need for a well-functioning pre-symptomatic ToBRFV test is very great. We even get questions here from the angle of vertical farming. We are currently conducting many demos, in which we send the first test kit with the necessary hardware and then go through the test online, so that growers can use the test optimally.”
Rogier indicates that early detection of ToBRFV is necessary to prevent major crop losses. “Outsourcing testing often takes too long and is costly. Embedding periodic testing in the protocol prevents major damage. In addition to growers adjusting their protocol and testing more with the right pre-symptomatic tests, we see that they are also testing more at the gate.” For example, growers test incoming plant material before planting. “Even with young plants about thirty centimeters high, we have seen that the test can show that the virus is present.”
Cucumber mottle virus
Due to virus pressure, the necessary tomato growers have also started growing cucumbers. They also encounter viruses here. A well-known virus is the cucumber mottled virus (CGMMV). As announced at the end of last year, Spark Radar now also has a test available for this. “Only a leaf test at the moment, because we want to see how much demand there is for this test in the coming months. If that demand arises, we will continue with more test options, just like with ToBRFV.”
Needle in a haystack
“We are now focusing on these two viruses before adding new viruses and pathogens to our test range. Our goal is now to help growers find a needle in a haystack. With the extra test options for ToBRFV, we have taken steps in this direction. For example, growers first take a water sample and then zoom in with a leaf sample. This way they know better where to look for the virus.”
For more information:
Roger van der Voort
3584 CH Utrecht