Production of Certified Seed: Inspections and Rogueing

Certified Seed Rogueing

Rogueing is in full swing at many seed production plants at this time of the year. Rogueing is the removal of any unwanted plants by hand from a crop and it is routine for both the Department of Food and the Marine (DAFM) and seed companies to carry out this process along with a number of other crop inspections, especially in seed crops. Regular crop inspections ensure the crop is extremely clean of both weeds and off-types and rogueing is just one procedure to ensure the purity of certified seed produced here in Ireland.

Simply put, off-types are plants that have varying characteristics. During the rogueing stage, characteristics observed are; the plants themselves, weed contamination and in the case of Oilseed Rape (OSR) the leaf shape is observed. OSR off-types tend to have a larger yellow leaf or have curled anthers as opposed to straight.

A clean field of barley, after rogueing.
A clean field of barley, after rogueing.

For cereal crops, regular crop inspections are carried out to identify weeds or wild oats that may be present in the field. When inspecting fields, it is important to inspect near hedgerows and around ESB poles. If there are any sheds present in the field, these areas may also be home to weeds or wild oats caused by the inability of the sprayer’s boom to get in close enough.

Carrying out regular inspections allows potential issues to be identified earlier and rectified quicker in the season. One of the most common weeds present in cereal crops are wild oats. Depending on the crop, wild oats can be sprayed for or rogued by hand.

As the rogueing process is carried out by hand, the practise usually involves a team of people walking in a linear line through the crop. Each roguer is responsible for 3 strips of oilseed rape or a 4 metre strip of cereal crops and as they walk at a slow pace through the crop, they continuously rogue off-types, looking behind occasionally to view the crop from a different angle to identify any missed plants. Each rogue plant identified is pulled and discarded. To ensure the team do not miss any off-types a team leader will walk at a slow pace behind to detect any missed plants.

The overall aim is to insure the quality and purity of the crop is at a superior level as these seed crops will be sold commercially. Stringent crop inspections and monitoring allows for the production of excellent quality crops in Ireland year after year. Additionally, it gives Irish farmers peace of mind when purchasing certified seed that has been produced to an excellent quality and purity standard.

Additional Information:

  • Rogueing is the removal of any unwanted plants by hand from a crop, these are then discarded in the field or bagged and removed from the field.
  • A Roguer is a person that works at removing off-types, weeds etc. from the field by hand.

Key considerations for crop inspections:

  1. Continually monitor the stage of the crop to judge optimum rogueing time.
  2. Note the level of off-types present to judge number of roguers required.
  3. Recruit a trained eye as experienced roguers are invaluable in identifying the off-types/weed species.
  4. A team leader should be present at all times to offer guidance to roguers and for spot checks.
  5. A clean crop at the end of rogueing process gives superior quality and purity to the seed.