Posted on June, 4, 2021 at 08:06 am
Sesame also known as Sesamum indicum is one of the oldest oil crops to be grown by farmers dating from 1600 BC.
In Natural Sciences a book written by Pliny the Elder, he mentions the cultivation of sesame seeds in areas of Greece and Asia Minor before it spread to the African continent with many countries taking the lead in its cultivation.
Background
As described in a May 16, 2018 Agonomag publications, sesame is an oily plant, as the seeds contain 60 per cent oil and 24 per cent protein.
According to April 2020 report by Common Agriculture in Small holder and Agribusiness (CASA), in 2014, Uganda was the seventh largest producer of sesame seeds in Africa and the 12th in the world.
Quoting FAO statistics, sesame production peaked at around 216,000 tonnes in 2012 but recently settled at around 124,000 tonnes. This can be partly explained by the use of recycled seed and inadequate knowledge on gaps by farmers.
Sesame seeds are commercialised in various forms and most of them are used to produce oil, but the seeds are also suitable for various bakery products and other goods of the food industry.
Raw or roasted sesame seeds are high in demand on the food market across the globe.
As such, agronomists at the National Semi Arid Agricultural Recourses Research Institute (NaSARRI) in Serere District have joined the initiative to breed hybrid varieties for farm adoption.
Seeds of Gold spoke to Dr Walter Anyang a senior agronomist and simsim breeder at the Institute about best practices farmers can adopt to obtain bumper harvest and below are the details.
Plant attributes
Dr Anyang explains that sesame is part of the Pedaliaceae plant family and the species Sesamum indicum is usually grown.
The crop it is not resistant to drought and its best productions are obtained on fertile soils, with medium texture and deeper groundwater.
The soil should be well drained but not waterlogged and fertile land with sandy loam soil free from concretions is the most suitable.
It can be grown in rotation following crops such as maize, sorghum, millet or cotton, or it can be grown as a mixed crop with millet and sorghum.
There are usually two types of sesame seeds used for farming with the white-seeded suitable for the bakery industry and the blackish for oil production.
Varieties
Before the introduction of the hybrid varieties, farmers in Uganda have been growing indigenous varieties named after their communities. They include Teso simsim, Oturtata (grown in Lango and Acholi) and Arut variety.
Hybrids
However scientists at Serere have bred two varieties Sesim 1 which is sometimes called organic because it can grow in farmer fields minus spraying. The scientists released it in 2003 and it is mainly grown in Lango and West Nile. Its yield capacity is 700 kilogrammes per hectare and it is drought tolerant with 38 per cent oil content. It is good for the confectionary industry where its seed is roasted and stuck on bread.
The other variety is Sesim 2 released in 2013. It is resistant to gall midge pest. This variety has hairy stems which tend to prick the abdomen of the pest once it clings onto a plant. It is early maturing and within 90 days it is ready for harvesting.
Land preparation
Sesame grows slowly in the early stages of vegetation, which is why the soil must be free of weeds. It can be planted in soils that were previously used for legumes.
Regarding the fertilisation of sesame, it is important to know that about 70 per cent of the nutrients are consumed after the flowering period, which is why fertilisation is necessary during vegetation.
Soil preparation must be done early in order to create a loose, graded and levelled ground. Basic soil preparation techniques used are ploughing and harrowing.
Most farmers broadcast the seed but it recommended farmers plant it in rows where they can hold a rope along the row and spread in 3cm by 3cm.
Alternatively they can make farrows and spread the seed along the rows and once germination takes it is important to uproot crowded plants and leave a few in a row.
Weeding
Weeding is done manually after two to three weeks from germination time.
Farmers may choose to weed once or twice depending on the level of weed growth in a particular farm.
It is not proper to abandon the farm minus weeding because this may lead to fungal infections infesting the plants leading to poor yields. But in case of any infections, farmers are advised to use a recommended fungicide to spray the plants.
Pests and diseases
The major pest is the gall midge pest where the female midges lay eggs along the veins of terminal leaves. The larvae are typical maggots and they are whitish to orange in colour, legless and with body tapering exteriorly and they grow up to 3 to 4 mm in length.
The maggots feed inside the floral buds and young capsules leading to formation of galls of up to 6 mm in diameter.
They pupate inside the galls attack the flowers making it to wither and drop off or become twisted and stunted and do not develop into flower capsules.
The simsim gall midge is usually a minor pest, but occasionally high infestations occur resulting in considerable crop losses.
Another is the web worm which is a moth that hatch caterpillars which eventually make spider webs on the plants leaves thereby causing stunting.
This can be controlled by spraying with insecticides and uprooting infected plants to avoid further infection.
Harvesting sesame
The harvesting takes place when the fruit at the base are ripe, the seeds from the fruit get the colour specific to the variety and the leaves at the base of the stem have fallen. It is usually ready for harvesting between 90 to 120 days after planting.
On small surfaces sesame is harvested with the sickle and then bound into bundles, where it continues to dry without losing its quality.
It is recommended that drying is done on racks and thereafter threshing is done on trampoline to maintain cleanliness. Winnowing can be done using available winnowing tools until it is clean seed.
Maturity
The crop which takes only 120-140 days to mature also do well in a well-drained sandy soil with a pH value between 5.4 and 6.75. Sesame requires a temperature of between 26-30degC to blossom making it well adapted to the East Africa’s warm climate.
Storage
It is recommended that farmers must store unshelled sesame seeds in dry conditions, protected from rain and humidity. Shelled seed must be stored in sacks after drying to attain 10 per cent moisture content.
Bagged seeds should not be placed directly on concrete floors because of the high risk of dampness.
Source: The Monitor