by Brian Mhango

Socrates once said: “Nobody is qualified to become a statesman who is entirely ignorant of the problem of wheat.”

With that quote I thought of sharing a few interesting bits about wheat. Wheat was one of the first domesticated food crops, and for 8 000 years has been the basic staple food of major civilisations in Europe, West Asia and North Africa. It is grown on more land than any other crop.

World trade for wheat is greater than for any other cereal. The only other agricultural commodity traded more than wheat is soya beans. More foods are made with wheat than any other cereal grain.

Wheat provides more nourishment (calories & proteins) for humans than any other single food crop. Accounting for a fifth of humanity’s food, wheat is second only to rice as a source of calories in the diets of developing country consumers, and it is first as a source of protein.

Demand for wheat in the developing world is projected to increase 60% by 2050. At the same time, climate change induced temperature increases are likely to reduce wheat production in developing countries by 20 to 30%. (Wheat CRP, FAOSTAT).

I believe the above provides a lot of enthusiasm for farmers going into wheat production this winter. With wheat prices averaging $400 to 475 per tonne, dams steadily filling up in the wheat producing areas, coupled with a positive global demand for Mhangowheat, we believe there can be no better time than now to invest in wheat production.

One of the most important decisions to make for profitable wheat production is choosing the right variety or varieties to plant.

Many differences exist between varieties, and it is imperative to assess what characteristics are important in a particular production area to reduce or manage risks. Growers are encouraged to diversify their risk by planting multiple certified varieties. This helps improve the chances of success. Certified seed ensures the highest quality with good germination and absence of noxious weeds.

The soil environment plays a critical role in optimising wheat growth, and development has consistently shown increased wheat yields with deep tillage. In fields with hard pans or compacted soils, tillage enables easier root growth and penetration, increasing the potential for water and nutrient uptake.

Tillage also serves to reduce surface residue that may host diseases and pests. In wet years, compacted, dense soils can result in very low soil-oxygen conditions, which can reduce yields of most small grains due to poor root production and nutrient uptake. No-till is less common in wheat production due to observed yield reductions ranging from 3 to 20%. With the understanding that no-till management often has a wheat yield penalty, it may be considered as a decision for the whole farm system to reduce erosion and save on tillage costs. Disking is a common tillage practice that can provide an excellent seedbed, but may lead to the formation of a compacted layer of soil. The weight of the implement is concentrated in a very small area at the tip of the disk, and when disking is repeated several times, a hard pan can form.

Deep tillage (bottom or para ploughing or V-ripping) is the most reliable tillage option to optimise yield potential. It is slower and more expensive than disking, but is usually cost effective with improved yields. When double-cropping field operations make it impractical to deep till, chiselling or subsoiling can be a beneficial alternative.

Consistent and proper seed placement will influence the uniformity of emergence, final stand, and potential yield of wheat. Good seed soil contact with soil moisture promotes rapid emergence and good root development.

Wheat should be planted at least 2,5 to 4 cm deep when soil moisture is adequate for good germination. Take care to achieve uniform planting depth, as poor depth control leaves seed too deep or too shallow for uniform emergence.

Planting wheat with a properly calibrated planter is preferred over broadcasting, as uniform emergence is very difficult to achieve when broadcasting wheat. Numerous studies have demonstrated that higher yields are consistently achieved with a properly calibrated planter compared to broadcasting.

It can be beneficial to establish a row traffic pattern at planting or soon after emergence, for all post-emergence field traffic can be beneficial. Traffic patterns or tramlines can be established by closing one or more openings in the drill when planting the crop. This can be done by retrofitting the drill with clutches attached to the metering cup that can close the opening to leave unplanted rows that match the wheel spacing of your sprayer or tractor. Devices for drills can be purchased to establish tramlines on any tractor width in any multiple of drill widths.

Tramlines may also be established after the crop has emerged by chemically killing the rows that match the wheel spacing of the implement used to apply fertiliser or pesticides with glyphosate (Touchdown).

Precision agriculture tools such as light bars and GPS guidance systems can help reduce the error of overlapping when chemically killing rows to establish tramlines. This method should be applied early, once the wheat has one to two developed leaves. Using tramlines in intensively managed wheat enables uniform application of nutrients and pesticides with improved precision and timeliness. Tramlines can save on the cost of aerial applications, and can reduce the chance of disease development when compared to plants that are crushed by running over standing wheat. Studies have shown that the border plants will compensate 50 to 60% of the yield lost by the missing rows, whereas plant damage has far less impact on yields.

The planting date is another critical consideration of successful wheat production. Planting too early or too late reduces yield potential. Always plant late maturing varieties first, since these varieties most often have the longest vernalisation (the cooling of seed during germination in order to accelerate flowering when it is planted) requirements. Recognise, though, that some medium maturing varieties may also have long vernalisation requirements which make them less suitable for late planting. Vernalisation requirement vary widely with variety. In order for wheat to vernalise, temperatures must be low and remain cold for a specific length of time. In the absence of cold weather, wheat waits until enough heat units have accumulated, and nights are short before heading. The warmer the temperature during grain fill, the poorer the yield and weight. If wheat is planted late in the season, choose an early maturing variety because they have, in general, very low vernalisation requirements.

Optimum seeding rates for wheat can vary widely due to differences in seed quality, genetics, planting conditions or planting dates, and planting methods (drill or broadcast). Seeding based on seeds per hectare is much more accurate than seeding based on weight per hectare. Multiple seeding rate studies have been conducted throughout the country and most show that seeding of up to 240 plants per square metre (m²), with a seed rate of 110 kg to 120 kg per hectare is desirable. However, this will vary depending on seed size, germination and planting conditions.

Broadcasting requires a higher seed rate of up to 140 kg/ha as does planting under zero tillage. However, achieving this rate will require knowledge of seed size (number of seeds per kg). The use of certified seed will help to ensure that you are planting seed with a minimum germination of 90% and free of noxious weeds.

Planting bin-run seed is not recommended as it infringes on plant breeders’ rights (PBR). It robs seed companies of the chance to earn revenue on their innovation, and therefore undermine their ability to recoup their research and development investment.

Wheat production is done off the rain season around April/May, therefore it requires irrigation, with water requirement of 400 to 600 mm per season to guarantee a good crop.

Fertiliser application is also critical. Basal of 400 to 500kg/ha and top dressing of around 300 to 400 kg/ha are recommended.

Weeds compete with the crop for water, sunlight and nutrients, and it is critical that they are well managed with herbicides like Syngenta Axial, Dialen Super and Traxos.

You also need to look out for diseases and pests. Syngenta Amistar Extra, Cherokee, and Elastus Arc offer potent fungal control for rust, Septoria and powdery mildew in wheat for excellent yield results.

For growth regulation, Moddus (Trinexapc-ethyl) comes in handy as an anti-lodging agent by improving stem strength and providing an excellent root system. Common insects such as aphids and bollworm can be controlled with Ampligo.

May you all enjoy a successful wheat season!

For more information, contact the author: brian.mhango@syngenta.com, Head of Marketing Southern Africa and Seeds E2E.