A clean, healthy start

When greenhouse and nursery plants are at their healthiest during propagation, they have the necessary building blocks to develop a strong root system and turn into valuable finished crops. However, protecting plants before and during propagation can be a challenge, especially when transportation and growth environments can easily become conducive for disease development. “Despite the best planning and efforts for seamless delivery from farms to greenhouses, it’s inevitable in the business of spring production that your cutting deliveries may become delayed,” explains Jamie Gibson, technical lead at Syngenta Flowers. “An extra day or two in transit can create several issues for plant species that are susceptible to ethylene damage or tissue breakdown. Fungicide sprays should be applied as soon as cuttings are rehydrated and turgid to help minimize Botrytis problems on damaged leaf tissues.”

Once propagation begins, unrooted cuttings, seedlings and liners generally require warm temperatures and frequent misting or high humidity for proper rooting. But this warm, humid environment also provides optimal conditions for spores of pathogenic agents to germinate, invading wounds and tender plant tissue. During propagation, plants may be at risk of developing various diseases, including foliar blights caused by Botrytis cinerea, leaf spots caused by Alternaria, Colletotrichum and Myrothecium spp., as well as lower stem rots. Seedlings are also at risk of damping-off from Pythium, Phytophthora and Rhizoctonia spp. when the growing media is wet for a prolonged period.

Adopting strong cultural practices and employing preventive fungicide applications can help growers maintain a successful crop throughout production. And with the proper selection of fungicides used as part of an agronomic program, growers not only protect plants against pathogens but may even boost their crop’s overall health. 

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“Plant health benefits are additional advantages from the treatment that occur above and beyond disease protection,” says Gibson. “One example of a plant health benefit is enhanced rooting. Faster root development could result in a shorter crop time, as well as the production of more fibrous roots, which aid in nutrient and water uptake, and better growth. The additional benefits are due to positive effects on the plant’s physiology, which can vary according to plant species and growing environment.”

Strobilurin fungicides are best known for providing these plant health benefits as well as lower rates of transpiration, which maximize the efficiency of water use, and increased nitrate reductase levels in plants, which allows nitrates to be more readily available to produce proteins essential to plant growth.

“Strobilurin fungicides also reduce the production of ethylene, which delays senescence, consequently improving growth and plant vigor because of increased production of carbohydrates within the plant,” says Charlie Krasnow, research and development scientist at Syngenta. “These particular benefits promote better resilience in plants, which help them hold up better during shipping and improves shelf life at retail.” 

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Mural® fungicide from Syngenta features a combination of azoxystrobin and SOLATENOL® technology.

Azoxystrobin, a well-known strobilurin chemistry, is systemic and offers xylem mobile movement, meaning it is absorbed by the plant and translocated upward to protect new growth. SOLATENOL technology is an advanced generation SDHI (succinate dehydrogenase inhibitor), which binds to the waxy layer of plants and slowly penetrates the tissue, creating a barrier of protection. 

This combination makes Mural ideal for inhibiting spore germination and mycelial growth during propagation and throughout production, by providing protection for the plant inside and out.

“The active ingredient combination has a synergistic relationship. We worked hard to optimize this ratio,” Krasnow adds.

Interestingly, plant health benefits, such as root enhancement, are more often seen at lower use rates. Mural provides broad-spectrum disease control and offers plant health benefits at rates of just 4 oz. (foliar) or 2-3 oz. (drench), which are rates typically used on young plants in production for effective disease control.

“The technical team at Syngenta Flowers is a big advocate of Mural as we have seen its use be tremendously beneficial in managing Botrytis on several large cash crops such as geraniums, hanging baskets and potted flowering crops, especially when there are older chemistries that have been shown to be resistant to Botrytis,” Gibson adds. “Protecting umbels of geranium, hydrangea and pentas is critical during spring when the disease triangle (host, pathogen, environment) is present.”

In addition to Botrytis, Mural also provides effective control of downy mildew, Pythium and Rhizoctonia in rotation programs for ornamentals and vegetable plants grown for transplant including cucurbits, peppers, eggplant and tomatoes.

With its broad-spectrum disease control and plant health benefits, including increased root density, Mural is an ideal fungicide for use in propagation as a spray or as a drench. Its many use sites make it a versatile option for any grower. Learn how to get more with Mural at GreenCastOnline.com/Mural. 

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