With harvest just around the corner, it is time to talk about the final steps and decisions that you are going to take to get the crop in the bin. You want to make sure you choose the option that will be the most efficient and practical for your operation. When it comes to pre-harvest, there are several options available. These include swathing, contact herbicides, and systemic herbicides. The use of a pre-harvest desiccant can be a great harvest management tool to speed up harvest and help you make better use of your time.
The use of Reglone allows for a quicker dry down of your crop which helps get the crop in the bin faster. The quicker dry down will also help you to be more efficient by allowing you to combine faster, spread straw better, combine later into the night, and start earlier in the morning. Quicker dry down also helps you protect the grade of the crop and avoid any environmental factors that could delay harvest. Contact herbicides are best suited for desiccation of pulse crops. This option is also available for canola, but the dense canopy makes the dry down process a little more challenging for a contact herbicide.
Systemic herbicides such as glyphosate can be used alone or in conjunction with a contact, such as heat to desiccate a crop. This mode of action offers enhanced control for those trouble fields that have high weed pressure late in the season. It can take 10-14 days for Glyphosate to show activity on the crop, so the addition of Heat LQ can speed up the rate of dry down. The downside is, these products do not help the crop mature, which is why a timely application is so critical. Early applications can have detrimental affects on yield and quality. Systemic herbicides are most commonly used for desiccating canola acres. Depending on the marketability, these products may also be used on some pulse and cereal crops.
First off you will want to look at the field as a whole and see if there is a general colour change from green to yellow amongst the entire field. This colour change is indicating that the crop is reaching its natural maturity. Next, you will want to go into the field and make sure that the bottom pods are dry. This means that the seeds rattle in the pods when they are shook. The middle seeds should be starting to turn a lime green colour and can easily be split in half. The top seeds should be a brighter green colour and will still be a bit juicy.
Before applying a desiccant to peas you will want the field to have an overall yellow colour. The moisture content also needs to be less than 45%. This is measured when the seeds in the bottom pods are dry and translucent in colour. The middle pods should be green/yellow, full sized and split when squeezed. At the top, the pods will still be a green colour but beginning to turn yellow.
When spraying yellow peas, you will want to see an overall colour change from green to yellow throughout the field. The bottom pods should be dry with detached seeds in the pods that are translucent in colour. The upper pods should be starting to shrink and the seeds should split when they are squeezed.
Desi: You will want the majority of the plants to be yellow (the tops of the plants may still be green) and the seeds should be a yellow/brown colour.
Kabuli: The majority of the plants and pods should be ripe and dried down. You will want the seeds to be white/tan and detached from the pod.
You will want to apply the desiccant when the field is at the hard dough stage (less than 30% seed moisture). The easiest way to establish this timing is when you can leave a nail print in the kernel. It is best to scout in many different areas of the field to get an accurate assessment.
Heat LQ should be applied to when there is 80% seed colour change. In order to determine the maturity, you will need to open up the pods and asses the seed colour since the ripeness of the overall field may be deceiving. The seeds on the bottom ¾ of the main stem should be changed to a dark brown/black colour. Seed colour change can be a very challenging thing to assess, especially in years where the crop is in two different stages. It is important to scout many different areas of the field to get an accurate assessment.
Always be sure to check with your grain buyer to see what desiccated seed will be accepted before you spray!
For any more guidance on pre-harvest desiccation, reach out to your local SynergyAG retail!