Teagasc Tillage Update - 2 April

TILLAGE: Get some tips on spring barley; winter cereals; winter barley nitrogen advice; growth regulators and diseases. Watch videos on the fertiliser application rates required to match off takes and on fertiliser spreader calibration and set up.

After a prolonged period of inactivity on the land the recent dry weather has given tillage farmers a great opportunity to make progress with the spring workload. While initially land ploughed up wet the current dry spell has allowed farmers to give land an extra couple of days to dry out and seedbeds have generally been good. Good progress has been made with sowing around the country with the majority of beans, wheat and oats in the ground. The bulk of the remaining spring barley will be planted in the coming week.

Spring Barley. As we move into April increase spring barley seeding rate to 300 seeds/m². To achieve 300 seeds would require 159kg/ha (10.1st/ac) for a low TGW (45g) or 184kg/ha (11.7st/ac) for high TGW (52g). As planting moves into April it is important to incorporate N, P and K into the seedbed at sowing.

In this video, Mark Plunkett, Teagasc Tillage Specialist discusses the fertiliser application rates required to match off takes.

Winter Cereals. Growth in winter cereals has been steady over the past week but we are still waiting for the first flush of rapid growth. There are large variations in growth stages between crops. The earliest winter barley is at GS 30 but many other crops won’t be there for another week. Shoot count in barley is generally below average. Oats is similar to the earliest barley at GS30 but there are large variations in winter wheat depending on sowing date and crops range from early tillering to some early sown approaching GS30.

Winter Barley Nitrogen. The main split of nitrogen on winter barley will be the next task on winter cereals for many growers. Total nitrogen rate should be based on the yield potential of the crop. Two row barley would need in excess of 1,000 shoots to achieve high yield whereas six row barley can achieve high yields with 750 shoots. Where higher rates of nitrogen are being applied it is advisable to apply the main split at GS30 followed by a third split before GS32 to reduce the risk of loss.

Teagasc trials from 2012-2014 on 2 row, 6 row and 6 row hybrid barley varieties showed that while the nitrogen requirement does not need to be adjusted based on cultivar type the hybrid varieties generally have a yield advantage over 2 row varieties and that extra yield will require more nitrogen.

Table 1: Nitrogen strategy for winter barley

¹ Evidence of yields over 8.5t/ha is required for higher nitrogen applications

Even fertiliser spreading is crucial to achieving maximum benefit from fertiliser but also to prevent lodging.

In this video, Teagasc Machinery Specialist, Francis Quigley has some useful tips on fertiliser spreader calibration and set up.

Growth Regulator. Consider a split growth regulator programme where there is a risk of lodging. DAFM variety lodging rating, high tiller number and overall nitrogen rate are the main risk factors. PGR application at GS 30/31 will help to strengthen the base of the crop while a further application at GS32-39 will help shorten the crop. Apply Moddus (0.2L/ha)/Medax Max (0.2-0.3Kg/ha)+ CCC 1.0 L/ha mix at GS 30/31 in high risk crops but ensure the crop is not under stress, avoid tank mixes and do not spray when there are large day night temperature swings.

Disease. Teagasc fungicide trials on winter barley indicate that a two fungicide strategy at stem extension and awn emergence will deliver the best response. In seasons where disease pressure is high a fungicide at mid/late tilllering will give a response. Currently disease levels are low but watch Cassia and Tower in particular as early disease will lead to the loss of valuable tillers.