NORTHERN CORN LEAF BLIGHT
Northern corn leaf blight is one of the most common diseases of maize in South Africa, and while yield losses are typically minimal, they can become significant if the planted cultivar is susceptible.
The disease is caused by the fungus Exserohilum turcicum, and generally occurs before silking. It prefers moderate temperatures (around 18°C to 27°C) with prolonged periods of moisture. The fungus overwinters on maize leaf debris.
The University of Minnesota Extension (UME) says that the disease is usually more severe when infection occurs earlier.
FAST FACTS
Maize streak disease can cause stunting of maize plants and misshapen cobs.
Northern corn leaf blight can result in significant yield losses.
Grey leaf spot thrives in areas with warm temperatures and prolonged periods of high humidity (greater than 95%).
SIGNS AND SYMPTOMS
The UME says that typical symptoms of northern corn leaf blight are canoe-shaped lesions that range from 2,5cm to 15cm in length.
Initially, these lesions may be bordered by grey-green margins, which eventually turn tan colour and may contain dark areas of fungal sporulation.
The length or size of lesions may vary with different [maize] hybrids, the UME explains. Lesions generally begin on the lower leaves, before spreading to the upper leaves. Symptoms can progress rapidly, resulting in blighted leaves.
ESSENTIAL FACTS
• Pathogen: Exserohilum turcicum
• Typical signs and symptoms: canoe-shaped lesions, which are initially bordered by grey-green margins.
• Preferred conditions: moderate temperatures and high levels of humidity.
• Effects: yield losses.
Denne historien er fra Farmer's Weekly 3 February 2023-utgaven av Farmer's Weekly.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
Allerede abonnent ? Logg på
Denne historien er fra Farmer's Weekly 3 February 2023-utgaven av Farmer's Weekly.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
Allerede abonnent? Logg på
New farmers' seedling pitfalls
Inexperienced farmers may be tempted to grow seedlings from seed themselves, but they have much to gain by trusting a seedling grower at a nursery to perform this task for them instead
South African avocado production: a success story
Avocado production in South Africa has expanded markedly since the industry's humble beginnings over 80 years ago. From a small grove planted in 1938 in what was then Nelspruit, the industry has blossomed to seven million trees planted on 20 000ha. Dr Guy Witney, project manager at Great Brak Avos, spoke to Annelie Coleman about the country's avocado production.
Unlocking value through livestock exports
Exporting livestock might sound like a daunting business that's better left for big companies, but Gerrie Ferreira, who farms near Oudtshoorn in the Western Cape, has been doing it successfully for almost 30 years, sometimes in partnership with other breeders. He spoke to Glenneis Kriel about the huge potential this market holds, and offers some advice for farmers who are contemplating going this route.
An agribusiness's dedication to community upliftment
For agribusiness NWK, located in Lichtenburg, North West, corporate social investment is an important part of creating a positive influence alongside financial returns. Johan Bezuidenhout, NWK’s group manager of corporate marketing and communication, spoke to Annelie Coleman about why the company chooses to invest millions of rands in the area it operates in every year.
Empowering dreams, transforming lives
Since its launch in 2013, the Agri's Got Talent competition has revolutionised the lives of many farmworkers by unlocking their hidden talents and fostering a culture of empowerment. Glenneis Kriel spoke to various finalists about how the contest has changed their lives.
Foreign investment: agriculture maintains its appeal
South Africa remains a popular destination for foreign investors, despite an often negative outlook from its citizens. It is a gateway to Africa, and with its counterseasonal production to the Northern Hemisphere and favourable weather, local agriculture is especially well placed to attract foreign interest, bringing with it hope for rural communities
The real value and message of COP29 for SA agriculture
While the 2024 Conference of the Parties may have disappointed those who hoped for real progress, it's more important for South African agriculture to highlight its role in carbon mitigation
Improving efficiencies in feed and grain milling
Bühler, a Swiss-based company that provides solutions and equipment for various industries, including food and animal feed processing, has pledged that by 2025, it will deliver scalable solutions that will reduce energy, waste and water by 50% in the value chains of its customers.
Tips for better olive production
At an SA Olive Association field day in November, industry experts shared ways to improve olive production efficiencies, from soil preparation to harvesting.
More effort needed to protect vulnerable cheetah
On International Cheetah Day, commemorated every year on 4 December, emphasis was placed on the vulnerability of the species.
