Integrated Pest Management (IPM) trial.

Dew to the destruction of our sweet sorghum crop by Chillo partellus stalk borer last season, we had decided to partner with the Department of Agriculture in Eastern cape through its reaserch centre Dohne, to test the effectiness of the Push and Pull system in controlling sterm borers.The system is ussually used to control stalk borers in Maize in various countries in Africa and had been reported to be successful.


TITLE: Effects of intercropping with Silverleaf desmodium (Desmodium uncinatum) on Chilo partellus (Swinhoe) populations on Sorghum (Sorghum bicolor L.) plants in the Eastern Cape Province of South Africa

RESPONSIBLE OFFICER: N. Skenjana (Department of agriculture Eastern Cape Entomologist)


AIM: To control Chilo partellus on sorghum using push-pull strategies

Objective:
• To determine the effects of intercropping silverleaf desmodium with sorghum on Chilo partellus populations.
• To assess the potential of increasing income generation for smallholder farmers by reducing input costs and increasing crop quality

6. PROPOSED EXPERIMENTAL SITE: Forest View Farm, Chintsa East, East
London
7. PROPOSED TRIAL DURATION: 3 years (2010-2013)

8. JUSTIFICATION:
Chilo partellus (Swinhoe) (Lepidopteara: Pyralidae), an invasive pest, introduced from India in the early 1930’s has been recorded as one of the most important pests of cereals including sorghurm (Sorghum bicolor L.) (Moench) in South Africa and the rest of Africa (Kfir et al., 2002). Last February, it was found infesting and damaging more than 45% of sorghum in the Chintsa East area of East London. According to the agronomist who visited the site, the sorghurm was in its vegetative stage when most of the damage was noticed. The Plant and Crops production Research Services directorate of Dohne Agricultural Development Institute has since been receiving numerous specimens of Chilo partellus from different maize/sorghum farmers in the area asking for an intervention.

Sorghum is known to be the second most important cereal in South Africa after maize. Morever it has proven to be a gem due to its multi purpose nature and the fact that it has been found to out-perform other cereals including maize under various environmental stresses. It is crucially important to food security right now due to its uniquely drought resistant nature and the fact that it can withstand periods of high temperature. More than 35% of sorghum in Africa is grown directly for human consumption. The rest is used primarily for animal feed, alcohol and industrial products (Kangama and Rumei, 2005). Sorghum has also become one of the crops that are being used to produce bio-ethanol at practical scales for both rural communities and industries. A bio-fuels research programme has been established at the University of Stellenbosch for the production of bio-ethanol (Esterhuizen, 2009).

On the other hand, Chilo partellus is known to be a very good competitor, and there have been numerous reports of the pest displacing native cereal pests all over Africa. In the Eastern Cape province of South Africa, there are records of the pest displacing Busseola fusca (Fuller) (Lepidoptera: Noctuidae) an indigenous pest of maize and sorghum in higher altitudes. This apparently is attributed to the rise in temperature and the fact that C. partellus develops faster than the indigenous pest. None of the biological control initiatives introduced against the pest have established yet in South Africa. Chemical pesticides due to their association with risks to human and animal health, the fact that they tend to kill natural enemies and their contributions to environmental pollution are being discouraged as a unilateral approach to insect control. They are also blamed for the increase in input costs as a result making agriculture to be unaffordable to resource poor small-holder farmers. Entomologists are now encouraged to develop economically viable, sustainable and eco-friendly pest management strategies.

The push-pull system which uses a combination of behaviour-modifying stimuli to manipulate the distribution and abundance of insect pests and/or natural enemies will be investigated in this study. Trials conducted in different parts of Africa by ICIPE, and in the Northern Cape Province of South Africa by the ARC have been successful in controlling targeted stem borers. After successful on-farm trials, the push pull was then officially released in Kenya and is being disseminated through their extension systems. Most of the trials concentrated on intercropping maize with different wild grasses and legumes. This study will concentrate on sorghum as a sole crop due to the importance of sorghum in this era. The legume chosen for the study; silverleaf desmodium was also used in the trials conducted in Kenya and trials have yielded pleasant results. It has also been found to grow well in the East London area and farmers in the Eastern Cape Province are familiar with it.

Forestvale reaserch and training farm will during and after this field reaserch work be doing extension and training services to local farmers and Individuals who wish to gain knowledge on Integrated Pest Management.This is an important step taken to strengthen our Rural Agro-ecological Development initiative scientifically.