How to choose the best fungicide for black spots on roses?

Black spots on roses – or the fungal disease Diplocarpon rosae is considered the most prevalent and hazardous diseases affecting roses. Dark circular lesions with feathery edges appear on leaves, causing them to turn yellow, wilt, and drop off. This affects the plant’s blossoming and physiological health, reducing its overall vitality and appearance. Selecting the right fungicide is crucial for effective fungus management and prevention in rose gardens. This guide provides tips on choosing the right fungicide for black spots on roses, with a real-life example included.

Understanding Fungicide Options 

• Contact Fungicides: These fungicides do not penetrate the tissues of the plants and act by eliminating fungi as soon as the spores come in contact with them. They must be used often as they are washed away by rain or irrigation regimes. Some ones are chlorothalonil and mancozeb. 
• Systemic Fungicides: These are taken up by the plant and afford what is termed internal protection. This is longer lasting than the previous and can even offer protection to new growth. Some of the members of this group are myclobutanil, propiconazole, triforine among others. 
• Biological Fungicides: These are obtained from the natural environment and some of them consist of friendly microorganisms that are capable of the inhibition of the fungal pathogens. An example of a Class 4 product registered for use in the developed countries is Trichoderma foliar spray fungicide, which is a bio-fungicide. 

Case Study: This is the case of the Rose Garden belonging to the Jones’ family

The Jones family, living near Tribeca, USA, discovered black spots on their hybrid tea roses recently. Concerned about their roses’ health, they sought a healthy, efficient method to treat the disease or pest. Initially, they tried home remedies like neem oil and baking soda sprays, which only partially helped. Despite these measures, black spots persisted, especially during high humidity or frequent rains, raising concerns about treatment effectiveness. After research, they chose a fungicide, Trichoderma foliar spray, with Trichoderma harzianum, for long-term and short-term protection. The Jones family now considers it the best fungicide for treating black spot on roses in their garden.

Why Trichoderma Foliar Spray?

• Eco-Friendly: It is as natural product so it won’t harm the surrounding environment, beneficial insects, and the pets.
• Effective Colonization: Trichoderma on the plant rhizosphere and the course of protection is constantly provided throughout the life cycle of the plant.
• Dual Action: It not only guards against black spot but also helps the plant to be healthy by helping in the absorption of nutrients.
• Application: The Jones did the right thing by following all the right procedures that was set by the application guidelines that were necessary.
• Frequency: The spray was used at two-week interval during the growing season by them.
• Coverage: Guarantied that there was adequate coverage of both the upper and the lower surface of the leaf.
• Timing: Specifically used when the sun is not too strong especially in the morning and at evening.
• Results: In the space of 6 weeks the Jones noticed that the occurrence of the black spots was remarkably low. Another benefit of the treatments was the health of the leaves; the newly grown leave did not exhibit any signs of disease or infection. The overall health of the roses increased and the roses produced more flowers to which were of better colours and quality.

Things you should know before selecting the right fungicide

• Identify the Problem: Officials need to double check that the disease is black spot and not some other rose disease.
• Evaluate Options: Disadvantages and advantages of fungicides: Contact fungicides and systemic fungicides, biological fungicides.
• Read Labels: Use the recommended rates of application and observe all the recommended safety measures as recommended by the manufacturer.

Eradicating black spots in roses involves using sound management practices integrated with suitable fungicides. Organic remedies, such as the Trichoderma foliar spray fungicide that contains Trichoderma harzianum as its active ingredient, from Novobac pose an environmentally friendly/favourable and effective method, as seen from the outcome regarding the Jones’ rose garden. This paper seeks to understand that with the right fungicide, proper application methods, roses can grow healthy and beautiful all season. Now that you know how to control black spot on roses thanks to the best possible organic treatment for black spot on roses, you can stay stress-free.

References:

1. Amin, Faheem, et al. “Biological control of powdery mildew and black spot diseases of rose.” Journal of Pharmacognosy and Phytochemistry 7.3 (2018): 2826-2828.
2. Prasad, R. D., et al. “Biological control of black spot of rose caused by Diplocarpon rosae.” Annals of Plant Protection Sciences 10.2 (2002): 256-259.