Questions of the Week

How much does ‘set it and forget it’ cost at combining?

Changes in air temperature throughout the day — especially in standing canola in hot, drying winds — dramatically impact harvestability by changing canola pod moisture, crop humidity, even how air moves through a combine’s fans. According to research from PAMI, higher harvest losses occur in cooler conditions (ie: below 23^oC). That’s because when canola plants are harvested in the heat, they break apart more easily. When a combine is set for hotter weather settings but runs in cool conditions, whole canola pods may flow through and out of the machine. More seeds out the back end mean less marketable yield and a greater weed seed bank of volunteer canola. Check harvest losses (here’s how) and adjust combine settings at least twice per day: once in the cool am or pm; another time in the heat of the day. Combine settings should also be checked when pod shatter ratings or hybrids change between fields. (Harvest loss calculator) (Combine optimization calculator)

What went right and what could have gone better from seeding through harvest?

Using yield monitor data and fall plant counts, ask what factors robbed yield in-season:

• Disease: could seed treatment or timely in-season management have helped? Post-swathing is the easiest time to see disease identifiers including stem shredding, sclerotinia sclerotia, verticillium stripe microsclerotia and blackleg pycnidia. Free disease testing is available for clubroot, blackleg and verticillium stripe: click here for Saskatchewan and here for Manitoba.

• Fertility: did the crop get what it needed? Though it’s too early to conduct soil tests for next year’s crop, make a plan to fall soil sample for residual nutrients, basing sample locations on yield monitor data. Review uptake and removal charts and applied rates of fertilizer to estimate carry over or deficit of nutrients.
• Heat blast: could earlier seeding have decreased heat’s impact?

Fall plant counts are the first step to seeding rate decisions for next year. Though some fields have a higher than desired plant stand, this year’s excellent moisture at seeding was an anomaly. Could spindly plants and competition have been reduced with more fertility? Be cautious about cutting seeding rates next year. (Seed: plant counts influence buying decisions) (A good reason to count stems at harvest)

How to manage hot canola and/or high green seed at harvest?

Temperatures are forecast to go above 30°C this week in many regions. Even if hot canola is very dry when binned, convection currents moving through the bin will concentrate moisture in the bottom of the bin’s central core, creating moisture pockets and the starting place for hot spots. Use aeration to even out temperature and moisture variation. When using aeration to cool very dry canola, shut fans off when the air temp is more than 5°C warmer than the grain; keep them running if the air temperature is close to or cooler than the grain temperature. If canola is anything other than very dry, keep fans running continuously. Storage risk drops sharply if canola moisture is 8% or lower and temperature is 15°C or lower.

Green seed increases storage risk. While green seed locked in by frost can’t be reduced, trapped green caused by premature cutting or very fast dry-down can be reduced by reactivating the green-clearing enzyme. (Green seed common questions) (Harvesting in heat: cool that canola) (Importance of the early days in storage)

When is best to tackle weeds around harvest?

Next year’s weed control starts in the fall, especially for fields planned for LibertyLink. The decision of whether to attack perennial weeds before or after harvest depends on harvest timing, preferred product and specific weed species: more info here. 

• Pre-harvest: Diquat products will support crop dry down; glyphosate can control perennial weeds but should not be used as a desiccant; saflufenacil can promote both crop and weed dry down. To manage excessive product residue, pre-harvest glyphosate (whether applied as a stand-alone or with Saflufenacil) cannot be applied until canola reaches less than 30% moisture in the least mature part of the field. More details on application timing are here. Always check pre-harvest intervals.
  
• Post-harvest: wait several weeks (ideally 4-6) for adequate perennial re-growth post-harvest. For now, make a plan considering order of operations: how will fall tillage impact weed management?

(Pre-harvest aids and pod sealants) (Canola Encyclopedia: Harvest management) (Fall weeds – when to spray)