Replanting: Consider all the factors

October 2025

DR AART-JAN VERSCHOOR, SENIOR MANAGER, ARC AGRIMETRICS. FIRST PUBLISHED IN SA GRAAN/GRAIN, MARCH 2025

SOMETIMES, AT THE START OF A GROWING SEASON, A FARMER’S HARD WORK TO GET SEED INTO THE GROUND RESULTS IN POOR EMERGENCE. AT TIMES, THE DAMAGE TO A MAIZE CROP CAN BE SO SEVERE THAT IT CAN LEAD TO CROP FAILURE. THIS IS USUALLY THE RESULT OF A NATURAL PHENOMENON – PERIODS OF EXTREME HEAT AND DROUGHT, PESTS SUCH AS LOCUSTS OR WORMS CAUSING SIGNIFICANT DAMAGE, OR A STORM WITH HAIL, STRONG WINDS OR EVEN FLOODING.

TO REPLANT OR NOT
At this point, the farmer must decide whether there is still enough time in the growing season to achieve a harvest with the current crop stand, or whether it makes sense to replant. The question also arises whether it makes economic sense – whether costs can be recovered, and whether the farmer can still realise a profit. It can be even more complex: If no planting is done, the loss of income could harm the farmer’s reputation and future chances of securing financing.

As each farmer’s situation is unique as far as soil, the climate, other resources and crops are concerned, this is not an in-depth economic analysis, but just a suggestion of the principles that should be considered.

Farmers planting manually, trusting that there will be rain to help their crops grow.

IMPORTANT FACTORS TO CONSIDER
The farmer can start by considering a few key points:

• Determine the yield potential and value of the current damaged crop stand.
• Assess the yield potential and value of a replanted crop stand.
• Calculate the difference.
• Determine the additional replanting costs and compare them to costs already incurred.

Essentially, this is a cost-benefit calculation, which sounds simple but is not that straightforward.

The farmer may reason that he has already invested significantly in the specific field through soil preparation, pest and disease control and nutrient management. Decide whether this investment will still have value in the next season, or whether it should preferably be utilised now.

Another consideration is the costs that must be covered again – and here, the most important expenditure is seed. Depending on the crop, input costs are certainly one of a farmer’s most significant expenses – and seed is by no means a minor part of this. The availability, price and nature of the seed (such as a shorter growing season) will be significant here.

The farmer must also consider other additional costs such as mechanisation, fuel and labour. Time is also a crucial factor. Consider whether there is still enough time to achieve a harvest with the available cultivar, which is competitively priced.

In short, a percentage of the typical input costs for planting actually doubles. The primary consideration is whether the estimated additional costs still allow for a break-even point and the possibility of profit.

CONCLUSION
Two principles stand out:

• Firstly, the calculations must be accurate – precise figures are crucial. Yes, there will be assumptions about the yield, cost and price, but these are informed estimates. 
• The second principle is that the farmer must know his farm, soil and resources (natural, physical and human). This knowledge of the potential of given resources is decisive.

Furthermore, it is essential to know how long the window period for establishment is. There is no point in replanting if the expected yield is likely to be suboptimal.

Clearly, the decision to replant or not is not an easy one. However, an informed decision, based on reliable data and knowledge, is essential and can mean the difference between a crop failure and a reasonable harvest – or even a good result. 

Publication: October 2025

Section: Pula/Imvula