Improved simsim offers good yield

Simsim, also known as sesame, is an oil crop mainly grown in the eastern and northern Uganda by smallscale farmers.

The crop, according to experts, has small nutritious seeds which is a very important in processing oil and is valued for its high quality oil content ranging from 44-52 percent.

Despite its high value and potential, the crop has received less attention, with its production characterised by low yields and low productivity among smallholder farmers.

This is as a result of the impact of frequent extreme weather such as droughts, unpredictable seasons and too much rainfall.

Other challenges include use of traditional seed varieties and poor management practices. Others include poor pests and disease control practices, declining soil fertility, pre and post-harvest challenges, among others.

Background

Simsim is believed to have originated in Asia or East Africa. Ancient Egyptians are known to have used the ground seed as grain flour. The seeds were used by the Chinese at least 5,000 years ago and for centuries they have burned the oil to make soot for the finest Chinese ink blocks.

Other scientific theories suggest the cultivated type of sismsim originated in India.  Archaeological remnants of charred sesame dating to about 3500-3050 BCE suggest sesame was domesticated in the Indian sub-continent at least 5,500 years ago.

It has been claimed that trading of sesame between Mesopotamia and the Indian su-continent occurred by 2000 BC.

India ranks first in the production of sesame seeds and with the help of its tropical climate, the country is one of the best sesame seed manufacturers which supply high-quality seeds.

However, simsim production in Uganda is picking up at a slow pace which has intrigued interests from crop scientists to breed improved varieties farmers can easily adopt in order to increase production.

In a 2017 publication by Africa Innovations Institute about the initiative by crop scientists to apply smart climate agriculture to improve simsim production, it is noted that in Uganda, about 250,000 smallholder farmers are engaged in sesame production

Farmers who observe the best agronomy practices are able to harvest 101,000 metric tonnes from an area of 176,000 hectares. The biggest percentage of this production, 93.7 percent, is realised from northern Uganda including West Nile.

Concerted effort

It is therefore against such background that crop scientists led by the National Semi-Arid Resources Research Institute (NaSARRI) in Serere with colleagues from private research institutes such as the Africa Innovations Institute (AfrII), Uganda Oilseeds Producers and Processors Association (UOSPPA), FICA Seeds and the Ministry of Agriculture, are working jointly to carry out research in a bid to breed varieties that can improve farmers’ yields.

According to Dr Walter Anyanga, a simsim breeder at NaSARRI, over the years farmers have been planting traditional varieties namely Serra and Sesim I until recently when his team released Sesim II and III with qualities of giving good yields up to 800 tonnes per hectare under good agronomic practices.

Scientists from Afril have been evaluating the two varieties which are drought tolerant particularly in Lango sub-region in a bid for farmers to practice climate smart agriculture by observing the right time when to plant.

Farmers have also been sensitised in controlling the common pests and diseases to avoid yield loss.

Dr Anyanga explains that his team is currently evaluating about 10 lines which are due for testing in various agro-ecological zones in northern Uganda and West Nile where the promising lines resistant to drought and pests and diseases will be selected for release to farmers next year.

Commercial potential

He contends that simsim has commercial potential and currently there are companies exporting about 500 tonnes every season to China.

He notes that once the selected lines are released to farmers they production rate will increase and farmers will attain improved incomes.

Francis Alacho from Afril, who is part of the breeding team, notes that from the assessment made so far, the new lines are drought tolerant as well as resistant to common pests and diseases.

Farmers have been allowed to access Sesim II and III with experimental trials conducted with model farmers to enable them concentrate on growing these varieties instead of the traditional ones.

Trials have been conducted and released varieties of Simsim2 and 3 (Sesim 2 and 3) distributed to farmers to give them chance to select among the released varieties the most suitable. They are then to compare the performance and make a selection that they will adopt basing on the crop yield and resistance to pests and diseases.

The eight host farmers selected for the experimental trials are in the districts of Otuke, Lira and Amolatar. More districts will be brought on board later.

On the different trial plots, some were treated with fungicides spray while the fertiliser trials were for evaluating different fertiliser rates to establish which combination of fertiliser gives better yields.

Best practices

Dr Anyanga explains that while his team is conducting research to develop more high yielding varieties, for the time being farmers are encouraged to grow Sesim II and Sesim III while following best practices to get bumper harvest.

Soil and climate requirements

Fertile soils are important for its good growth and farmers can boost the soil fertility about 125kg fertiliser at seedbed. Warm temperature are suitable for it .

Sesame is mainly grown in warm area with little rainfall and it is the reason it is mainly grown in Northern Uganda.

Planting

It requires a fine seed bed on fine soil and planting should be done during the onset of the rain season and it broadcast method is the best because the seeds are tinny. This must be the rate of 6 kg- 8kg per hectare.

If planted in row ate spacing is 30cm by 10cm and seeds must be dropped at the depth of 3cm deep

It is important to thin the plants once they have attained growth of 3cm high leaving one plant per hole at 10cm distance between plants.

Weeding

The plant is sensitive to weed competition during early growth stages therefore the first weeding can be done two weeks from planting and the second one after thinning depending on the type of the weed.

Pests and diseases

The most common disease is gall midge which destroys the pods leading to yield losses.

The pests include web worm which consumes the leaves leading to stunted growth of the plant.

Harvesting

For the shattering types, harvesting should be done before capsules start shattering. Farmers are expected to harvest plants with a knife when leaves turn yellowish or have been shade.

Tie up cut stems into bundles and place them on racks to dry and once the cut stems are dry, thresh them manually to release the seeds.

But there are also combined harvesters used in other countries growing the crop on large scale

Value addition

The scientists explain that there are number of products to be made out of simsim starting with processing oil for the fresh cake as well toasted grinded paste.

Others are confectionery products where it is used on baked bread, it can be used for wine processing and chocolates including simsim paste used in source.