In August 2023, American Alex Harrell recorded the best soybean harvest in history on his farm in the state of Georgia. At 13.9 ton/ha the yield was significantly higher than the previous world record set in 2019 by Randy Dowdy who farms in the same state.

Harrell’s record was achieved in the US equivalent of South Africa’s Grow for Gold competition run every year by Grain SA, which means that the field on which the record was surpassed received a lot of special attention. While it is good to know what is possible (South Africa’s soybean-yield record, set by Jan van Heerden from Hartswater in August last year, stands at 6.668 ton/ha under irrigation), no grower can devote competition-level effort to hundreds, if not thousands, of hectares of soybeans. Under normal circumstances, growers aim for optimal yield without losing sight of profitability per hectare – the latter being only possible by achieving the best balance between input costs and yield.

“The basic principles must be adhered to protect crop potential well enough to realise maximum yield, especially given the tough, dry season South Africa experienced the past summer season,” says Hanlie Geldenhuys, row-crop expert at Syngenta South Africa.

The secret to protecting yield lies in growers controlling stressors that can be managed or manipulated to some extent, to the best of their ability.

Planning is the key

Geldenhuys says the prospects for soybeans are positive for the season ahead, due to favourable commodity prices and La Niña conditions, the likelihood of above-average rainfall. However, it is also true that fungi and diseases flourish in wet conditions, hence growers will have to be smart about disease and pest control. “A healthy soybean crop depends largely on a well-planned and executed spray programme. Steps taken on the spur of the moment are often too late and can be counter productive.”

Success with soybeans can be likened to a four-camp athletics event with every item, or stage, demanding focused attention and inputs.

Yield must be considered even before the first row is tilled. Seed treatment ensures proper germination, seedling vigour, even stand and robust root-system development, all of which result in strong, healthy plants. With such a head start, a good crop stand give the best chance of realising its yield potential. Syngenta’s APRON® Plus Beans seed treatment with CRUISER® as an add-on, is the recipe for an excellent start to the season. In combination, these products keep the fungi and insects that prey on seeds and seedlings in check.

Weed control early  in the life of a soybean seedling is of utmost importance to prevent yield losses. Weeds compete with crops for light, water and nutrients and can have a devastating impact on soybean quality and yield. A study done in 2006, found that weed pressure and competition place 37% of global soybean production at risk. In Ethiopia it was found that weeds can diminish soybean yield by up to 60%; a study done in America over six years put the loss percentage at 52%. Researchers further noted that weeds in fields during harvest can stain soybean seed and lower its quality, while also making harvesting far less efficient (https://www.cambridge.org/core/journals/weed-technology/article/perspectives-on-potential-soybean-yield-losses-from-weeds-in-north-america/839B31C6771865071E6956BAEFC0F076).

Growers therefore never have to debate the need for weed control – the science speaks for itself. A programme that combines Syngenta’s TOUCHDOWN FORTE® Hi Tech and METAGAN® Gold is a very good choice in the battle against weeds.

Insect pests can destroy a soybean crop, especially soil-borne insects that attack seedlings and root systems early in the season. To prevent insect damage, growers can start with KARATE® Zeon followed by AMPLIGO® which, thanks to its residual action, is particularly effective against bollworm. A bollworm infestation later in the season can decrease grain quality dramatically.

Disease control is the fourth step on the road to a profitable soybean season. When soybean plants start flowering, diseases that impair photosynthesis in particular are of great concern. AMISTAR® Xtra not only keeps diseases at bay, but also improves yield by keeping plants green for longer (which facilitates photosynthesis) and encouraging the uptake of water and nutrients. The result is stronger plants that are more resilient against sclerotinia – the soybean grower’s biggest headache for which there is no direct treatment.

Soybean production in South Africa is rapidly increasing and becoming one of the country’s economically most important crops. In a crop-rotation system, soybeans restore soil health significantly enough for it to be noticeable in the next season’s maize yield. Lower input costs and a favourable risk profile furthermore ensure that soy is profitable in its own right.

It is, therefore, worth the effort to invest in the planning and meticulous application of the right crop protection  programme. The optimal balance that can be achieved between input costs and yield , will go a long way to ensuring a winning soybean season.