The use of pre-harvest glyphosate will be a worthwhile exercise on many cereal crops this harvest: to improve harvesting speed, help maintain quality and to control any weeds which may have germinated in the crop.
For most crops 1.5 litres/ha of a 360g/lt glyphosate (e.g. Motif / Samurai / Rosate) is sufficient for harvest management and small annual broad-leaved weeds. More expensive proprietary glyphosate brands such as Roundup Energy or Glyfos Dakar will act faster and are more rain fast, however if desiccation is timed correctly this should not be necessary.
It is important to check with the merchant before glyphosate is applied to milling crops especially, and seed crops should not under any circumstances be treated with glyphosate. Certain malting barley contracts also prohibit the use of glyphosate for pre-harvest desiccation.
Skyfall was difficult to thrash out last season as its straw remained very green despite the grain being fit. Oats, both winter and spring, can also retain green leaf and straw making combining difficult.
The correct timing is when the grain is below 30% moisture; at this stage the grain should just take a thumbnail print. In most situations combining will be around 10-14 days after this, however the harvest interval of 7 days for most products must be observed.
Ripeness can also be assessed by checking the colour of the Peduncle just below the ear – when the crop is ready for glyphosate it will be yellow/brown as shown on the right most ear.