Stop leaf spots and fruit rots in cucurbits and fruiting vegetables

This article was updated in 2024 with additional information.

With summer approaching, most of your vegetable crop is in the ground and your disease management programs are well underway. However, as weather conditions change, so does the risk of different diseases.

When it comes to tomatoes, peppers, and cucurbits, managing fungal leaf spots to maintain crop canopy preserves the potential for high yield and quality.

Check out the summaries below to learn how to maximize your application of Syngenta vegetable products to manage diseases caused by fungi:

Cucurbits: What conditions promote disease?

What solutions to try?

What to try? (FRAC Group)	Spectrum	When to try and why?	L/acre*
(29)	Alternaria leaf spot Gummy stem blight  Downy mildew	Early in season to break up other groups due to the long pre-harvest interval of 30 days	0.3 to 0.7
(M5)	Powdery mildew  Anthracnose  Scab  Downy mildew	Flexible timing to protect vegetative growth early, or use as a dependable rotational partner later on.	1.9
(3 + 11)	Powdery mildew Anthracnose  Gummy stem blight  Alternaria leaf blight	Typically applied at flowering. Two active ingredients provide broad-spectrum protection.	0.3 to 0.4
(7)	Powdery mildew  Anthracnose  Gummy stem blight  Cercospora leaf spot  Alternaria leaf spot  Alternaria leaf blight	During fruit set, translaminar activity with long-lasting protection found in SOLATENOL® technology.	0.2 to 0.3
(3 + 11)	Powdery mildew  Anthracnose  Gummy stem blight  Alternaria leaf spot  Alternaria blight**	Applied during fruit development, the ADEPIDYN® technology component of Miravis® Duo provides extended control into harvest.	0.4

Leaf spots, like gummy stem blight and anthracnose can often be confused with angular leaf spot. Keep in mind, the products that protect against leaf spots won’t protect against bacterial diseases. Explore products to target water molds like downy mildew in cucurbits. 

Check out the side-by-side comparison with Miravis^® Duo in zucchini and squash from 2019 and 2020. 

 
 

Tomatoes: What conditions promote disease?

What solutions to try

What to try? (FRAC Group)	Targets	When to try and why?	L/acre*
(M5)	Early blight Anthracnose Septoria leaf spot Late blight Botrytis grey mould	Flexible timing to protect vegetative growth early or use as a dependable rotational partner later on	1.0 to 1.9
(3 + 11)	Early blight Anthracnose Septoria leaf spot	Typically applied at flowering, two active ingredients provide broad-spectrum protection.	0.25
(7)	Early blight Anthracnose Septoria leaf spot	During fruit set, translaminar activity with long-lasting protection from SOLATENOL® technology.	0.2 to 0.3
(3 + 7)	Early blight Anthracnose Septoria leaf spot Alternaria canker and rot Botrytis grey mould** White mould**	Long-lasting protection with ADEPIDYN® technology when applied during fruit development provides extended control into harvest.	0.4

The rules for chlorothalonil are different for processing tomatoes and staked tomatoes. Review the details. 

Looking for more information on controlling late blight in your tomatoes? Talk to your local input supplier, connect with a Syngenta rep, or check out the Ontario CropIPM site for more information. 

Peppers: What conditions promote disease?

What solutions to try

What to try? (FRAC group)	Spectrum	When to try and why?	Product/acre*
(3 + 11)	Anthracose Powdery mildew	Start applications at flowering, rotating FRAC Groups for resistance management	0.25 L
(7)	Anthracnose		0.2 to 0.3 L
(3 + 7)	Anthracose Powdery mildew Botrytis grey mould** White mould**		0.4 L
(9 + 12)	Anthracnose Botrytis grey mould		0.31 to 0.39 kg

*Always consult the product label to confirm the application rate and targets by crop.

Looking for more information? Check out this article on Phytophthora in peppers by Horticulture Specialist, David Jefferson. 



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