20
Oct 2020

Light fluctuates like a yoyo

Light fluctuates like a yoyo

More challenges for growers

 

Last week light levels were erratic with some fantastic days proceeded by very dull, wet and windy days. Some crop reports showed 25% less light compared to the previous week.  The weather pattern is not uncommon for this time of the year but never the less it is extremely hard on older crops or crops with high fruit load. Sun is definitely a grower’s best friend; however, it is those pesky clouds which throw spanners into the works.

When the sun does burst through it is extreme and crops can flag very quickly, even if they have the best root system a sudden shock can cause plant stress.  Even though I promote the use of both wind and lee vents equally it has become necessary, in certain situations to reduce wind side vent activity to maintain relative humidity and protect crops.   The changing of seasons creates additional challenges with increased wind gusts, which again makes it difficult to liberally use the wind side vent.  Personally, I like to ensure the wind side vent is active to allow good airflow patterns and distribute ambient Co2 evenly.   This is especially important for growers that do not use supplementary Co2.  My advice though is to protect the crop, it is a change of season so be mindful of your wind side vent settings/influences.

 

Light Diffusion:

For glasshouse growers it is ideal to apply diffused products such as Redufuse or Redufuse IR.  Growers that have access to roof sprayers, or able to justify a helicopter, to apply the products are reaping huge benefits from plant health and an increase in crop production.  The issue is unless you have a custom-made sprayer, or are prepared to engage with a helicopter spraying contractor, it is perceived cost prohibitive to apply the products.  I floated the idea of using drones for smaller growers but this idea is yet to come into fruition (to my disappointment as it is rather appealing).  Smaller growers need a system that can spray their greenhouse safely and efficiently using a spray boom that is light and easily transferred from gutter to gutter.  Temperatures are increasing and the weather more extreme, these products offer growers a huge opportunity to improve not just production but help maintain quality outcomes for their produce. 

I have personally seen the huge benefits of using coatings such as Redufuse.  I fully endorse the product and believe all growers could benefit from spreading light more evenly throughout their crops and if you use Redufuse IR you could also reduce heat radiation, by it bouncing back off from the glass or plastic greenhouse. 

When it is time to remove the diffused coatings, you will require Reduclean to remove the coating in the Autumn.  This has to be done.  By doing this you also kill two birds with one stone, you remove the diffused coating and clean the glasshouse at the same time. 

Cover image taken this week.

 

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

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

Article Written and compiled 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