Combining pea desiccation

If you are considering desiccating combining peas, the correct stage of application is important.

Moisture content should be between 40-45% when the crop is turning yellow, bottom pods are parchment-like and the seed is hard. Middle pods should be pitted and crinkled, pods becoming parchment-like with rubbery seeds within. Top pods will still be fleshy and still green/yellow.

If desiccation takes place too early when insufficient lignification has taken place, the haulm can collapse, the crop lodges and yield may be affected.

Intervals between desiccation and harvest will vary depending upon the weather. Following applications of diquat, crops are usually ready for combining 7-10 days later.

Glyphosate is available pre-harvest to control excessive green weed growth, but work at PGRO has shown it has little desiccant action in peas. Generally at least 7 days will have to elapse between application and harvest, and average moisture content should be below 30%.

Pre-harvest glyphosate should not be used on seed crops. For further information see Technical Update Number 150 on the PGRO website.

Field bean desiccation

As well as increasing production costs, there may also be loss of crop from the passage of the sprayer. Desiccation will not advance seed maturity and has a slow effect on green stems. However, if the crop is infested with green weedy material or has a few late set pods which are still green, application of a desiccant will aid combining.

It is important to apply the desiccant at the correct stage of maturity. Application before this stage may result in reduced yield or loss of seed quality.

The most widely used material is diquat. Agral can be added - but consult processors if the crop is destined for human consumption.

Apply when 90% of the pods are dry and black and most of the seed is dry. At this stage, most of the leaves have senesced and fallen, but the stems are still green. The contact action is fast and harvesting can be carried out 4-7 days later. It can be used on crops for animal feed, human consumption or seed.

Glyphosate is not a true desiccant but can be used as a pre-harvest treatment to control perennial weeds. It must not be used on crops destined for seed.