Confidence on every level – Rootstocks with endurance and vigor deliver high-performance

Tomato rootstocks are the basis of a highly productive crop. Healthy roots help enable good water and nutrition uptake, especially under harsh conditions. Strong rootstock with endurance and a good root system can support plant development, which may help minimize the severity of symptoms throughout the season.

We are conducting continued research on the role of rootstocks in ToBRFV transmission and resistance performance in substrate and soil. We are working to accelerate the penetration of high ToBRFV resistance in our rootstock portfolio while keeping the high level of agronomic performance our customers have come to expect from Vegetables by Bayer.

*Ct stands for Cycling times. It is the number of multiplications of a specific part of the virus RNA that’s needed to detect the virus.
A Ct value less than 32 indicates the virus is present. A Ct value of more than 32 indicates the virus is no longer present.

Rootstock influence on scions and ToBRFV levels

There is little information about ToBRFV in the roots of tomato plants. The effect of the rootstock in relation to the scion and ToBRFV levels has not yet been investigated, so Vegetables by Bayer conducted trials under glasshouse conditions in The Netherlands.

The trial was set up as follows: A resistant and susceptible variety were each grafted onto a susceptible rootstock and a resistant rootstock. The scions were inoculated first with Pepino Mosaic Virus and a week later with ToBRFV.

Twelve days after inoculation, the ToBRFV concentration in the scion was measured. The susceptible scion showed a similar concentration of ToBRFV whether it was grafted to a susceptible or a resistant rootstock. The virus concentration in the scion was already high, and soon after, the first symptoms were visible. The resistant scions resisted the ToBRFV longer, and there was no influence from the rootstock, whether resistant or susceptible.

After 35-40 days, the susceptible scions showed severe leaf and fruit symptoms and the resistant scions showed some symptoms after 50 days. The experiment ended after 3.5 months, and the final examination showed hardly any leaf symptoms and no fruit symptoms in the resistant varieties, whether grafted on susceptible or resistant rootstocks.

The experiment was conducted in early spring in the Netherlands, so light conditions were low, representing a difficult period of the year for tomato cultivation. As such, more experiments and research are needed as we continue the experiments to complement our knowledge and in turn, better inform you.

These trial results do not contradict the value of strong rootstock as a base for good production. A good rootstock provides advantages during the entire crop cycle. And strong rootstock with endurance and a good root system can support stronger plant development, which may lead to less severe infections throughout the season. Many growers and plant raisers tell us they prefer a strong rootstock with endurance. A new and less strong rootstock is seen as a higher risk for good production. Even if the rootstock is not resistant to ToBRFV, the power and the strength of the rootstock are a secure base to help enable the best production.

_{Reference: * A Novel Platform for Root Protection Applies New Root-Coating Technologies to Mitigate Soil-Borne Tomato Brown Rugose Fruit Virus Disease Eyal Klein 1, Elisheva Smith 1,2, Chen Klap 2,3, Elena Bakelman 2, Arie Ophir 2, Aviad Sela 3,4, Elena Poverenov 4, Dmitry Rein 5, Yachin Cohen 5, Dan Eliahu 6, Shai Shahal 6, Guy Mechrez 4, Karthik Ananth Mani 4, Pulikanti Guruprasad Reddy 7, Abraham J. Domb 7, Nadav Pass 1 and Aviv Dombrovsky 2,* 35 =  Dombrovsky, A.; Mor, N.; Gantz, S.; Lachman, O.; Smith, E.}