Mechanical haulm topping – the smarter choice

The first potato may only come out of the ground on harvest day, but the groundwork for that harvest starts weeks earlier. This can make a real difference to tuber quality, skin set, storage life and harvesting efficiency. That said, one issue remains in the spotlight: the best way to manage potato haulm destruction. 

Chemical desiccation has been part of the pre-harvest toolbox in many regions of Africa for a long time. But due to rising input costs, pressure to farm sustainably and changing chemical regulations, growers have had to explore alternative solutions.  

Mechanical haulm topping is the solution – and it’s fast gaining ground. It reduces the growers’ dependence on chemical input and does not compromise on harvest preparation or quality. But why is haulm destruction so important? 

Getting the haulm under control 

The process of haulm destruction is straightforward: stop vegetative growth and allow the crop to concentrate on tuber maturation. Done two to three weeks before harvesting means potatoes develop a stronger, more mature skin set. This matters when potatoes are about to undergo lifting, handling, transport and storage. 

Haulm destruction is therefore far more than a routine pre-harvest job. It is a critical crop management decision, and one that increasingly has growers looking beyond chemical desiccation to a solution that offers better storability with fewer losses, a quality crop to sell … and greater profitability. In a nutshell, less haulm, less hassle, more harvesting. 

Mechanical for more control and benefits 

Mechanical haulm topping offers a direct, controlled solution. Rather than relying on a chemical to do the job, the haulm is physically cut, crushed and shredded, with the material deposited between the ridges. The result? A rapid reduction in plant biomass and a cleaner field ahead of harvest. GRIMME identifies mechanical haulm topping as both a sustainable alternative and a valuable supplement to chemical programmes, delivering benefits on two fronts. As this shredded plant material breaks down, it returns organic matter to the soil, supporting soil structure and contributing to a more sustainable production cycle. 

For the grower’s potatoes: 

• Improved skin set and storability
• More uniform tuber maturity
• Reduced risk of virus contamination
• Greater harvest maturity
• Improved crop quality  

For production efficiency: 

• Mechanical haulm destruction reduces the risk of blockages at the intake of the harvester, can increase throughput, means less component wear and more productive harvesting days
• When harvesting conditions are right, mechanical haulm topping can happen immediately
• Less dependence on chemical inputs 

Meet the TOPPA 

GRIMME’s TOPPA range of mechanical haulm toppers has been designed specifically for potato harvest preparation. The machines crush and shred the haulm before depositing it neatly between the ridges, promoting uniform crop maturity and creating ideal conditions for lifting. 

In Southern Africa, growers commonly work with the TOPPA 200, TOPPA 400 and TOPPA 800, offering options suited to different farm sizes as well as being able to perform in demanding field conditions. Selected machines can also be fitted with RidgeRunner ridge pressing wheels. These press the ridge after topping, helping to close cracks that could expose tubers to direct sunlight and potentially increase the risk of them developing before harvest.

Mechanical haulm topping offers greater control over crop preparation, less reliance on chemicals, a cleaner path for the harvester and improved crop quality. A better harvest doesn't begin when you start lifting. It begins when you start preparing. 

GRIMME offers a range of TOPPA haulm toppers for controlled efficient production