06 July 2023, New Delhi: Imagine investing time, money, and effort into a crop and walking through rows to find curled, crinkled leaves, vein swelling, yellow mottling, shortened plant height, and, worst of all, a poor fruit set that indicates a near total crop loss. It’s not a pretty picture, right?
First identified in India, crop losses from Tomato Leaf Curl New Delhi Virus (ToLCNDV or New Delhi Virus) make that unfortunate scenario a reality for many squash, melon, and cucumber growers around the world. Growers need solutions that help protect their crops – especially in squash production where the virus is especially challenging.
“This virus is widespread and especially active in the Mediterranean Basin,” said Peter Szungyi, Syngenta Vegetable Seeds Portfolio Manager for Watermelon and Squash. “The number one priority for growers should be to prevent the virus vector from entering fields and tunnels, but we know that’s not always possible. That’s why finding varieties with resistance is such a high priority.”
The disease pressure can be high in open field environments, but viruses like ToLCNDV can be often found in protected crops where they can quickly spread and cause damage. Spain, Italy, and Morocco have identified the biggest infestation of the virus, but it has been discovered in many additional areas where squash is grown.
“We identified this virus as a potential issue for melon, squash, and cucumber crops years ago,” said Pedro Pleguezuelo, Syngenta Portfolio Manager for Melon and Cucumber. “Because of this, our research and development teams started working diligently to identify resistances in each of these crop types to support growers.”
Virus Resistance Combined with Genetic Excellence
Whether the resistance to a pathogen is discovered by crossing elite squash materials or by crossing with related wild biotypes, the varieties developed and made available for growers must provide the same high yield potential, good plant characteristics, and quality of fruit they’ve come to expect.
“Our goal is to find squash varieties and resistances that work in different environments so growers have solutions wherever the virus might appear-both in the open field and protected environments” said Guillaume Menet, Syngenta, Squash Breeding Team Lead. “This means we’re dedicated and using our experience in breeding squash, to develop the right parental lines and create new hybrids with the desired agronomical traits and the resistance to all of the diseases that matter-including ToLCNDV.”
With the efficiency of a data-driven breeding methodology, Syngenta researchers can identify and select high-potential parental lines to focus their efforts on developing New Delhi resistance and, in turn, offer more favorable varieties to the growers.
“These data-driven decisions give us the opportunity to continuously improve our research and development processes and operations, which accelerates product development and commercialization,” says Jesus Abad, Syngenta Head of Germplasm Development for cucurbit crops.
Today, breeders are trialing and evaluating many potential squash varieties to find the best option for ToLCNDV resistance. This means varieties that protect fruit quality, preserve yield potential and give growers another tool in their toolbelt against this damaging virus that’s spreading around the world.
Building on Years of Experience
While the New Delhi virus is top-of-mind for growers in affected areas, it’s not the only disease to protect crops against, nor the only desired characteristic. Having wholistic disease resistance is critical along with high yield, good plant performance, and high-quality fruits consumers have come to expect.
Researchers are building on more than just squash experience, too, Syngenta has already identified ToLCNDV resistance in cucumber and continues research into melon resistance as a leading cucurbit innovator. In cucumber, look for the Siriana variety for not only New Delhi resistance but resistance to key diseases and pests.
