17 August 2001

Grain cracker waits to tackle winter barley

THE third week of SACs whole-crop monitoring trial, sponsored by FSL Bells, sees winter barley ready for harvesting using a grain cracker, writes Lothian-based SAC senior adviser Chris MacDonald.

Sampling on Aug 2 followed a week of much warmer weather which led to rapid growth. Winter barley is close to harvest, having ripened considerably over the last week. It has a light yellow appearance overall, but with some greenness around the nodes.

Winter wheat, spring barley and spring wheat remain green, although spring barleys lower leaves and awns are yellowing. With a high proportion of green leaf, all three crops still have potential for further growth.

Light rain was falling when crops were sampled. Winter wheat has overtaken winter barley as the highest yielding crop. The two spring crops have also grown well during the past week, particularly barley.

Head dry matters have increased, with winter barley going from 56% last week to 75%. But straw DMs are still only about 30% dry matter, even for winter barley.

Winter barley grains are quite hard and difficult to split with a thumbnail. This is the stage where it could be harvested using a forage harvester fitted with a grain cracker. The forage harvester can be set at different heights to vary the proportion of grain to straw, depending on desired feed quality.

Although winter barley is becoming rather dry for crimping, the addition of water could still make this a possibility. Winter wheat is at the soft dough stage, while spring barley is slightly ahead with a firmer dough texture.

Grains in these two crops are close to the stage where, if left unprocessed, they would pass straight through cattle. It is, therefore, getting too late to harvest these as whole-crop, but too early for crimping, where a target of 60% DM is required.

Spring wheat is some way behind the rest at the milky ripe stage, which is the period where it can be considered for cutting as traditional fermented whole-crop. &#42


Description of whole-crop heads on Aug 2


Winter barley Winter wheat Spring barley Spring wheat

Growth stage 91 85 87 75

Grain texture Grains hard Soft dough Medium dough Medium milk

Colour of head 0% Green 100% Green 100% Green 100% Green

Fresh yield (t/ha) 13.0 17.6 15.2 10.2

% dry matter 75 38 44 30

Yield dry matter (t/ha) 9.7 6.6 6.6 3.0

% of crop (DM) 66 44 50 34


Description of whole-crop straw on Aug 2


Winter barley Winter wheat Spring barley Spring wheat

Colour 5% Green 100% Green 100% Green 100% Green

Height cm 85 73 70 72

Fresh yield (t/ha) 17.3 28.4 30.5 22.1

% dry matter 30 30 21 27

Yield dry matter (t/ha) 5.1 8.4 6.5 5.9