April is the month when winter barley crops develop the fastest and demand for nutrition is at its highest, according to Teagasc.
Depending on the total amount of nitrogen (N) that growers intend to apply, the last split should be put out before growth stage (GS) 32.
Barley does not use late N efficiently and needs it working before the flag leaf is visible.
Manganese deficiency is common and needs attention.
Where fungicide programmes are concerned the decision to use a two- or three-spray strategy will depend on the variety and location.
Growers should use a three-spray programme on susceptible varieties, for example Cassia, where disease levels are moderate or high.
This is especially the case in the southern half of the country. Some of these crops have already received their first fungicide spray.
On crops in the northern half of the country, and on clean varieties, growers may be able to get away with two applications at GS31-33, followed by GS39-49.
It is also worth highlighting that the awns peeping stage is the ideal timing for that final fungicide to control ramularia.
Many growers still apply a flag leaf spray followed two or three weeks later with the final application to the head at GS59-69.
In Teagasc trials this has resulted on average, in a decrease in yield of almost 0.2t/ha.
Fungicide tank mix options include Siltra at 0.6L/ha, Decoy co-packs, Elatus Era at 0.8L/ha, MacFare Xpro or Proline at 0.4L/ha plus an SDHI (Imtrex, etc.) or strobilurin.
Where mildew is evident, growers should include a mildewicide.
Folpet should be included at 1.5L/ha to the last spray for the control of ramularia. It has been shown that, in barley, half rates of azole/SDHI/strobilurin fungicides will give adequate control. This will approach will also help to keep costs down.
According to Teagasc, winter oat crops that were planted last autumn have progressed well considering the wet winter they experienced.
Most crops are between GS30 and 31. Disease is evident in some crops and with options limited, it is important to choose the best product or products for each situation.
Prothioconazole products will give good control of mildew. Where pressure is high mildewcide should be included in the tank mix.
The addition of a strobilurin or SDHI will improve rust control.
All winter oat crops should receive their full N application by first node stage. It’s important not to apply more than 150kg/ha, as this will increase lodging pressure.
Trials from Oak Park also indicate that such an approach will reduce yield and quality.
Generally, the optimum N rate for winter oat crops is between 120-150kg/ha. Exceeding this risks reducing hectolitre weight and so is not advised.
Many crops will already have received a plant growth regulator (PGR). However, Teagasc trials show that the best growth regulation is achieved when crop is at second node (GS32-33).
Options include CCC 75% at 2.0L/ha or Ceraide at 1.4L/ha or CCC at 1L/ha plus Moddus at 0.2L/ha or Meddax Max at 0.2kg/ha.
Disease control in winter oat crops should start early with the first signs of mildew.