28
May 2019

Blight

Blight

Like clockwork, it has reappeared

 

Like it was scripted, I have been alerted of the first suspected case of Blight in a tomato crop.  I went and had a look and took these photos below.  Please be vigilant as the weather is perfect for Blight.  Don’t hesitate to go to your local horticultural supplier and purchase the necessary products to treat Blight if you see it.  Remember Blight = Plant Destroyer.  It will rip though a crop in a matter of days if left untreated, however if treated it is controlled almost as fast.

Above photos taken 28/5/19 

 

Below is from article written last year 21st May 2018:

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.  

To read full article click link below:

news/post/blight-is-back–react-and-prevent/

 

 

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

Article Edited by Marie Vogrincic, Editor, 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

Winter Bites
June 15, 2026
Winter Bites
Low Light, High Disease Pressure and the Importance of Keeping Crops Generative. Winter is often the period that determines whether a crop finishes profitably or simply survives until spring. The next three months will test growers' ability to manage light, energy, disease pressure and plant balance more than any other time of the year. As light levels decline and cold, wet weather becomes more frequent, we begin to see the typical winter challenges emerge. Across a number of sites I have already noticed the first signs of Botrytis and blight appearing. Once conditions favour these diseases, they rarely move backwards without intervention.
Signify expands Philips GreenPower LED toplighting force portfolio with tailored solutions for today’s diverse grower strategies
June 15, 2026
Signify expands Philips GreenPower LED toplighting force portfolio with tailored solutions for today’s diverse grower strategies
New Performance and Elite versions empower growers to optimize either upfront investment or long-term operational efficiency—without compromising on Philips quality
Signify: Developing next-generation cultivation systems that shorten growing cycles while maintaining consistent crop quality
June 1, 2026
Signify: Developing next-generation cultivation systems that shorten growing cycles while maintaining consistent crop quality
Signify boosts crop productivity and cost competitiveness at Yonam University smart farming hub with intelligent Philips LED lighting
Ground-Source Heating: Lessons from a Leading UK Greenhouse Operation
June 1, 2026
Ground-Source Heating: Lessons from a Leading UK Greenhouse Operation
An in-depth look at the ground-source heat pump system heating Stewarts Garden Centre in England and the opportunities this technology may offer commercial greenhouse growers in New Zealand. "Energy costs in the UK are currently extremely high compared with New Zealand. During discussions on site, electricity pricing was described as sitting around 22 pence per kWh, which converts to approximately NZ$0.50 per kWh. Considering those energy prices, the efficiency of the heating system was particularly impressive".
Demystifying stone wool for strawberry cultivation
May 19, 2026
Demystifying stone wool for strawberry cultivation
“Stone wool can make it easier for growers to face some of the current challenges”
Turn sunshine into synergy and unlock higher yields year-round
May 5, 2026
Turn sunshine into synergy and unlock higher yields year-round
How LED intercanopy lighting complements high radiation and transforms greenhouse production
CLASSIFIED