West: Final leaf 3 emergence slow in cold conditions

As always when I sit down to write this blog, I am determined not to talk about the weather too much, but it is difficult not to. It influences so much of our decision making, as crop growth is partly driven by air and soil temperatures.

The cool, showery and breezy conditions since last time I wrote has meant that spray opportunities have been very limited and equally frustrating. This has meant that quite a few T0s were not applied until mid-April, although on some farms I was pleased I amended plans to include some chlorothalonil.

Final leaf 3 emergence has been slow, but not surprising as phyllochron [period between leaf emergence] is directly related to thermal time. The night time frosts and cold northerly winds holding back day time temperatures recently means that thermal accumulation has been slow. I found myself field walking last week looking for leaf 3 emergence in hat, gloves and in a snow shower. Very few T1s have been applied in April, but if we get them on in the first week of May they will still be on target to hit leaf 3 and the tip of leaf 2 on the majority.

So far I am pleased with the response to grassweed herbicides applied in March, but it is too early to assess control levels as brome, in particular, has the infuriating knack of recovering and producing heads despite looking distinctly sickly 3-4 weeks after application.

Winter barleys are not romping away and still looking fairly short. The usual shock of seeing awns emerging has been replaced by questioning “is that the flag leaf?”. However, barley can put on a lot of growth after GS37 and I am sure once we have some warmer weather we will see them bounce, so late plant growth regulator (PGR) timing will have to be carefully monitored. If the awns are out it is too late.

Rhynchosporium has continued to develop in the showery conditions and an SDHI will be used at T2, as the crop still looks to have good potential, with good tiller numbers that are required to maximise yield.

Winter oats in most seasons are the crop that looks well all winter, but this season they went into a really stressed, purple state across all my farms in early spring. They are only just starting to pull out of this state, so I hadn’t put any spring sprays on oats before the end of April. Luckily mildew hasn’t been rampant, but they are in need of some fungicide and herbicide to tidy up broad-leaved weeds. I will probably separate the PGR applications, as I like to time when they have bounced into rapid spring growth.

The drier conditions last week did allow soils to dry out enough for the remaining of my spring beans, barley and oats to be drilled on the heavier ground and we managed to grab some early morning spray windows to apply the pre-emergence herbicides on the beans and barley. The last couple of seasons’ spring crops have performed pretty well, but these were drilled much earlier than this year. So these later drilled crops are going to require the weather to be very kind to get anywhere near.

The weather forecast suggests that we will see some warmer weather return this week, which is much needed to get things back on track in what has continued to be a frustratingly slow start to the season. I think I may have repeated myself again!

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