Scout your crops in June & July

June 2018

The area intended to be planted to wheat in the country is estimated to have slightly increased from the actual 491,000 hectares (with a national yield of 1,524 million tons at an average of 3,1 tons/ha) planted last season, to an estimated 500,200 ha’s this coming season.

Actual average yields varies from 1,8 tons/ha average in the Western Cape, 8,2 tons/ha in the Northern Cape reflecting the yields realised in the large area under centre pivot irrigation to 4,1 tons/ha in the Free State which is a combination of dryland production and pivot irrigated wheat.

Wheat prices for delivery in May 2018 are at R3 825/ton and look to be on an uptrend going forward. This implies a value of R5,931 billion for the 1,55-million-ton crop to come.

Each farmer has differing production circumstances whether producing wheat under dryland or irrigation. The yield potential differs from province to province but even at 1,8 tons/ha value of about R7 000/ha is to be managed and protected.

Constant scouting of the crop for weeds, pests and diseases must take place immediately after planting to ensure that the final yield targets are realised.

Planting periods
Recommended dryland planting dates of cultivars for winter wheat production range from the 7th of May in the North Western Free State through June and July up to the 7th of September for a late planted winter wheat cultivar in the Eastern Free State. Irrigation areas will be planted mainly in June to July. Dryland production in the Western Cape is usually confined to be planted the month of May.

Each farmer will be busy scouting their wheat crop from the exact planting date on their own lands and this will differ quite drastically from other areas. During June and July, the crop will have emerged and be in the early stages of growth. The onset of secondary root development is very important to note as this factor will greatly impact the final yield.

Scouting
Field scouting is the regular inspection of wheat lands to measure the start, progress and critical development of any pest levels that can impact the well being and final yield of your crop. Pests mentioned in this definition include any insects, weeds and diseases having a possible negative impact on the crop.

A knowledge of pest biology and being aware of the pests occurring in your production area is critical to be able to evaluate any changing condition experienced. Regular scouting prevents unnecessary treatments and expenses if the pest has not yet reached a pre-determined level of negative yield and thus total income. It is critical to choose and grow cultivars that are resistant to Russian Wheat aphids and various leaf, stem and stripe rusts depending on your production conditions.

Weed infestations are critical at the seedling stage and your chemical control supplier should be consulted to recommend the correct treatment at an appropriate and cost-effective stage of the crop development. Daily observation of your crop and formal scouting should take place at least once a week. You can also assess whether your management strategies are working or in fact causing problems. 

Guidelines
Use a 1 metre by 1 metre steel grid to measure the number of weeds per square metre. Take a pocket knife and sample bags with you. Walk through the whole land in a zig-zag pattern to comprehensively assess for weeds, pests and diseases. Be focused and as observant as possible to see the absolute detail of what is happening at the various growth stages. With insect infestations an assessment of number of insects occurring per leaf is important. For disease scouting check for plants that show signs of stunting, lesions, discoloration, yellowing or dying early.

The farmer can also monitor the effectiveness of the fertiliser programme during the development of the crop in terms of colour, growth stage, secondary rooting and later the stooling related to the actual plant population that emerged.

Conclusion
Comprehensive crop scouting will enable you to realise your optimum yield targets by being able to timeously address and treat any pest problems that might arise.

Article submitted by a retired farmer.

Publication: June 2018

Section: Pula/Imvula