The University of Kentucky Department of Agriculture recently published the results of a significant advancement in the management of Southern Root-knot Nematode (Meloidogyne incognita) in high tunnel tomato production through the use of grafted tomato plants. This innovative approach offers a sustainable and effective method for combating this pervasive pest, ensuring healthier crops and higher yields for Kentucky's tomato growers.
High tunnels (covered structures) provide a protected environment that extends the growing season and allows growers to capture premium prices through improved yield and quality. High tunnels rely on passive heating and cooling, meaning that temperatures inside the tunnel can increase rapidly on sunny days and cooling the high tunnel is largely done through venting or opening the sidewalls and end walls. Studies have shown that increased soil temperatures and overall daytime heat in high tunnels increase yield and optimize early season production for specialty crops such as tomatoes (Solanum lycopersicum L.) compared with open field production
Southern Root-knot Nematode (SRKN) is a notorious pest that infests the roots of tomato plants, leading to reduced plant vigor, lower yields, and significant economic losses. High tunnels are particularly susceptible to SRKN infestations due to the warmer soil temperatures and intensive cultivation practices.SKRN often goes unnoticed until the plant is pulled out of the soil at the end of the season and the galled roots are visible.
An alternative management strategy, which can reduce the need for chemical applications, is the use of RKN-resistant crops. Resistant cultivars are often used as rootstocks, the root system, rather than bred for fruit production. These resistant rootstocks can be grafted to susceptible tomato cultivars that produce desirable fruit by using a silicone tube to secure the union of the scion, the upper fruiting body, to the rootstock
Some of the key advantages of using grafted tomato plants are the following:
- Enhanced Resistance: Grafted tomato plants combine the desirable fruit characteristics of high-yielding varieties with the robust root systems of nematode-resistant rootstocks, providing superior protection against SRKN.
- Sustainable Solution: Grafting is a chemical-free method that reduces the need for nematicides, promoting environmentally friendly farming practices.
- Improved Plant Health: Grafted plants often exhibit increased vigor and resilience, leading to healthier crops and higher productivity.
- Economic Benefits: By reducing nematode damage, grafted tomatoes can significantly increase marketable yields, enhancing profitability for growers.
The intensive cropping environment of high tunnel production can lead to increases in population densities of RKN. UK researchers see benefits in grafting with resistant rootstock, as it can help growers manage RKN and maintain yield. However,more rootstocks should be studied to widen the market of resistant rootstock. Growers will also still need to use other management strategies in combination with resistant rootstocks to decrease population densities as well as manage high tunnel temperatures to the best of their abilities. Grafting resistant rootstock can be used to complement other integrated pest management approaches in high tunnel tomato production systems with RKN infestations.
The full article can be read on the HortScience electronic journal website at: https://doi.org/10.21273/HORTSCI17141-23