Category: Growing Degree Days

Growing Degree Days

Kicking off Primo Maxx II, 2024

Primo Maxx II Keep Using It


GDD 101 – And reasons to keep the program ticking over even though Summer’s done

Growing Degree Days

Primo Maxx II – Can I trust the model when its this hot?!

If you are in the UK you will know its been very hot recently, and Ireland has seen its share of the heat wave also; Dublin’s Phoenix Park recorded 33.1C (91.4F). The hottest day in 135 years across the island of Ireland. I saw on the news that the UK had its hottest night on…

Growing Degree Days

The calculator is wrong!

A quick one… When looking at the GDD calculator on the Syngenta turf website. Sometimes people look at the high temperature and the low temperature and ask the obvious question. 12.1 + 6.7 / 2 = 9.4 not 8.8. Well yes and no If you’re working Growth Degree Days out for yourself that’s exactly how…

Growing Degree Days

Growing Degree Days – 0c or 6c?

If you’ve been studying the Greencast GDD calculator you’ll see this is the time of year when there is huge differences between 0c and 6c base temperatures. Of course the immediate reaction is that something is wrong. But it’s important to note:- by using different base temperatures we are measuring very different things and those…

Growing Degree Days

Primo Maxx II – when to start?

At this time of year I regularly get asked when should I start my Primo Maxx programme. I’ve added some additional complexities to it this year, because I’ve been talking a lot about growth degree days. Primo Maxx has been used for a long time now and I’ve seen a lot of different timings and…

Growing Degree Days

GDD – Why I’ve changed my mind

Last year I was talking a lot about using 6C as your base temp for timing your PrimoMaxxII programmes but now I think 0C is probably best. I shared this with the turf managers of the Nordics last week. Growth Degree Days are a really simple model for measuring temperature based activities. Generally there are…

Growing Degree Days

Unlock and Play – GDD edition

Can Yorkshire deliver any stress? That’s the question I usually open with and at last the answer is yes! This week I’ll take a look at why GDD (Growing Degree Day) models are still useful during high stress periods if you have that stress under control. After a pretty dull July the first 2 weeks…

Growing Degree Days

Unlock and Play – The Wear Edition

The last review I did of this trial asked the question – Can Yorkshire deliver any stressful climatic conditions? That answer to that is no (not yet anyway). So we’re going to add some artificial stress – just like managing turf – with wear. What stresses can we control? Since Yorkshire isn’t renowned for its…

Growing Degree Days

Beginners guide to Primo and GDD

What is Primo Maxx II? Primo Maxx II is a growth regulator that is used in sports turf primarily to regulate and suppress grass growth. That has advantages for time and cost savings, but also some real advantages for maintaining consistent surface playability. You can vary the amount of suppression you get by increasing the…