Reducing mechanical damage

Mechanical damage is physical damage to the seed which penetrates the seedcoat such as cracks, chips, and holes. It is currently assessed visually and reported as a percentage. 

At CSD, we work hard to ensure every bag of planting seed that is delivered to the grower is of the highest quality possible.  

What causes mechanical damage?

Damage can occur during any stage of processing or seed handling including – picking, ginning, delinting, grading, treating, bagging, storage, transport and planting. Cottonseed is highly processed so there is a lot of potential for damage. The seed production conditions can make some seedlots more susceptible to mechanical damage with dry conditions during seed maturation being a risk factor for elevated mechanical damage. This is because low seed moisture content can make seed more brittle and susceptible to cracking during handling. Some varieties may be naturally more prone to mechanical damage than others (such as low density seed type varieties). 

How does CSD minimise mechanical damage?

CSD uses seed handling systems specifically designed to minimise damage, CSD processes have been optimised to minimise seed damage and the seed increase team work with gins and growers to minimise damage during picking and ginning. 

How does CSD reduce mechanical damage? 

CSD has a very comprehensive seed grading and cleaning system. Traditional processing based on size, density or aspiration can reduce levels of mechanical damage through the removal of broken and immature seeds, however, they are generally ineffective at selectively removing mechanically damaged seed. Last year CSD implemented colour sorters in the grading system. These use visual imaging to detect and remove damaged seeds. They will not remove all damaged seeds (pinhole damage for example is outside the detection limit) but significant mechanical damage can be reduced. 

Can mechanical damage affect germination?

Yes, it is possible for mechanical damage to affect germination. If damage is sufficient to affect germination or vigour, this will be reflected in the warm and/or cool germination test results. Germination testing is conducted on representative samples containing both damaged and undamaged seed, therefore germination results provided represent the entire seedlot, including any mechanical damage present. A proportion of reported mechanical damage is typically superficial seed coat damage and has little to no impact on seed physiological quality. 

What can I do as a grower?

Mechanical damage field trials and assessments of high mechanical damage commercial seedlots in the post controls have previously demonstrated that seedlots with higher levels of mechanical damage are still capable of achieving strong field establishment. The greatest risk associated with higher mechanical damage seedlots is generally planter performance, not germination. Damaged seed coats can produce additional seed coat fragments during planting. These fragments may accumulate within the planter metering system and partially block planter plates. If plates are not cleaned regularly, uneven seed placement and reduced plant stands may result.