Freeing up the valuable commodity of time with savvy agronomy – Blog #2

Freeing up the valuable commodity of time with savvy agronomy – Blog #2

Andrew Gilchrist, Managing Director of Scottish Agronomy
20th May 2020

Does everyone agree that an easier life is preferable to the harder version? Yes?….Then let’s look at how some simple agronomy changes can help to free up that valuable commodity – time.

Growing crops is a highly technical business these days. To get the most efficient outcome, all the agronomic ‘ducks’ need to be in perfect alignment: the best variety choice for the soil-type / location / sowing timing; the most cost-effective cultivations; the optimum crop protection programme; the optimal nutrition: balancing soil availability, organic, and out of a bag.

Timings need to be precise to get the best out of all the above, which brings in the biggest, fattest duck, which only occasionally will fall into line – the weather!

The weather is friend and foe. The current sunny, dry spell is brilliant for photosynthesis and helping to suppress wet weather diseases but causing crop stress as well. Timings may have to change, tank-mixes may need altering, and fertiliser availability is delayed. Same thing (but worse) for wet weather. All conspiring to spoil the best laid, technically sound agronomy blueprints. So, what can we do to mitigate this?

Potentially the next two examples could help.

  • Be smarter about variety choice

Choosing the highest yielding variety on the recommended list may sound like a logical choice if yield is the biggest decision driver. But bottom line really relates to cost of production – the lower the cost of production, the more money will be made. If you have to spend a fortune on crop protection, it may well negate any advantage in choosing a high yielding but needy variety. An example of this is in our managed Recommended List wheat trials. There is a dramatic difference between varieties in terms of their response to fungicide. Let’s look at the response to fungicide input for two popular varieties over the last three seasons.

Variety Treated Yield Untreated Yield Response to fungicide
Barrel 11.11 t/ha 9.02 t/ha 2.09 t/ha
Sundance 10.74 t/ha 10.16 t/ha 0.58 t/ha

As you can see, a substantial difference between the two varieties. It can be argued that the higher  treated yield of the Barrel justifies the spend, but this is a very robust (and expensive) fungicide programme, with four passes over the crop. If you reduce the spend and/or miss-time the key fungicide passes (T1 and T2), the yield response will also slip. There is little in the way of wiggle room. The Sundance however, although ultimately with lower yield potential than the Barrel, is a different proposition if spend on fungicide is reduced or timings are missed. Much more flexibility and much less risk. Also scope to reduce passes over the crop – creating more time!

  • Don’t spray if there is no evidence it works

The oilseed rape crop has been around in Scotland since the early 80s. It is our largest area break crop for cereals. We have learned a lot about how to get the best out of the crop over that timescale. We learned initially that the varieties back then were pretty responsive to fungicides – particularly in controlling our most common (and potentially damaging) disease – Light Leafspot. The old varieties were highly prone to the disease, and we used to use fungicides a lot – up to six times a season. The fungicides worked pretty well and yield responses justified their use. Things have changed more recently, however. Our varieties now have superior resistance to Light Leafspot and are stiffer. The other concurrent element is that fungicides are no longer very effective in controlling LLS. Put these two factors together and the previously ‘standard’ Autumn fungicide application is unlikely to produce any return on investment. This has been documented time and time again in our trials and also in split field comparisons. Is there any recent evidence out there to contradict this? We are not aware of any.

Further to this, other sacred cows are being challenged in the stem extension spring fungicide timings. Again, we are observing that if there is no significant established LLS infection at this point, there may be little benefit from a routine fungicide application. Our most recent trials results indicate a better return on investment from more emphasis on fungicide application during the flowering time. This period also sees other key diseases such as Sclerotinia, Botrytis and Alternaria potentially rearing their head, and concentrating the spend on fungicide during this period utilising their efficacy on more than one disease makes their use more efficient. Fairly radical perhaps, but we have evidence. Potentially reducing spray passes by two? Must be worth considering?

Both examples show that with robust trials data and timely application of fungicides aligned with you choosing the correct variety for your situation will benefit your farming operation bottom line.

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