21
May 2018

Blight is Back, React and Prevent

Blight is Back, React and Prevent

Blight is Back, React and Prevent

 

Blight identified in a tomato crop

 

Be on the lookout for Blight.  A crop of tomatoes in the Pukekohe area had what I could determine was Late Blight.  It was a quick fix with a common known fungicide.   The Blight was first sighted underneath a gutter row, a common place for the start of many funguses.  The trick with Late Blight is to react immediately, its not named ‘plant destroyer’ for no reason. 

The weather is still warm and there has been no shortage of rain in the past few weeks.  Perfect conditions for Blight.  This, along with windy conditions, mean the spores can travel far and wide!   Unfortunately, unless you have used a preventative, then it will just be a matter of good fortune if you don’t get Early or Late Blight, (especially in or around Pukekohe).  Early Blight is not as destructive as Late Blight but never the less you need to be vigilant.

Prevention is key but that doesn’t help once you have Late Blight, especially seeing how it can severely affect your crop in less than 48 hours.  You can have the best hygiene in the world but if your vents are open nothing will prevent spores from entering your greenhouse.  However, good hygiene practices are extremely important.

Unfortunately, it is hard to pinpoint what products you can use that are biological or organic to eradicate Late Blight once you have it. Copper products could control or slow down Late Blight epidemics but full coverage of the plants is required.  The Phytophthora infestans sporulates can survive on top of or underneath leaf surfaces.  Is there a way of protecting your crops with biological products?  

There are conventional preventive fungicides available, as long as you can use these products, and not exceed MRL’s (maximum residue levels), then I would recommend using them until we have better understanding and availability of biological products.   Personally, biological is the direction I hope we are able to take as an industry.  However, we must not dismiss chemicals and need to make sure they are our safety net, especially if biological products can not quite keep funguses like Late Blight in check.   I am concerned that there might come a day the chemical fungicides will not work as well, so using biological in conjunction with chemicals could extend the life of certain chemicals we currently rely upon.  It is a discussion I would like to have with growers and receive their thoughts.  

 

I would really like to hear the feedback from growers on this subject.

 

Photo of what I predict is Late Blight,  The speed at which the Late Blight spreads is astounding. 

 

I appreciate your comments.  Please feel free to comment below or on the grower2grower Facebook page:

https://www.facebook.com/StefanGrower2grower/

Article Written by Stefan Vogrincic, Consultant, Grower2Grower

CLASSIFIED

Subscribe to our E-Zine

Sign up here to subscribe to the Grower2grower Ezine. Every two weeks you will receive new articles, specific to the protected cropping industry, informing you of industry news and events straight to your inbox.

More

From This Category

Pukekohe Young Grower of the Year 2024 Competition and Awards Dinner
Grower2Grower annual golf tournament set for Friday the13th of September!
May 6, 2024
Grower2Grower annual golf tournament set for Friday the13th of September!
Sponsorship - we encourage you to enquire early to secure promotion opportunities: contact marie@grower2grower.co.nz today!
Horticentre Charitable Trust Continues as Exclusive Sponsor of Grower2Grower
April 23, 2024
Horticentre Charitable Trust Continues as Exclusive Sponsor of Grower2Grower
"Together we share a goal of offering future growers, and existing growers, a tool set, of credible trusted information, to achieve better outcomes".
Lefroy Valley’s Hydroponic Display Days-showcasing their newest lines
April 23, 2024
Lefroy Valley’s Hydroponic Display Days-showcasing their newest lines
Recently Lefroy Valley hosted a hydroponic field day to display lettuce varieties for the whole head and salad cut market.
What pests and diseases have caused tomato growers issues this past season?
April 9, 2024
What pests and diseases have caused tomato growers issues this past season?
TomatoesNZ asks NZ Commercial Greenhouse Tomato Growers to complete a short survey.
A brewing new industry for the North
March 12, 2024
A brewing new industry for the North
Ngawha Innovation & Enterprise Park progress with Specialty Coffee Project
CLASSIFIED