daniel chigunwe
Agriculture Specialist Writer
KUTSAGA Research’s successful 75-year tobacco seed genetic evolution history has reached the high-yielding climate smart variety era (2020-2025) where harvest potential has more than quadrupled from one tonne to over four per hectare.
To fulfil the objectives of the Vision 2030 of leaving no one and no place behind, National Development Strategy 1 (NDS1) and Tobacco Value Chain Transformation Plan (TVCTP), Kutsaga is spearheading production of climate-smart varieties (T78, T79, T80 and T81) currently on limited release programme in agro-ecological regions 4 and 5.
These varieties are being tried in Masvingo, Matabeleland North’s Insiza district, Lower Gweru and Mashonaland East’s Uzumba district.
Speaking at during recent tobacco seed and variety field day recently Kutsaga plant breeder, Dr Chenjerai Kashangura said their institution’s 75-year history started with the cultivation of the early KE1 variety, which underwent research and development from very low yields to the current yield potential of 5 000 kilogrammes per hectare for most KRK varieties.
The event was running under the theme: ‘Celebrating 75 years of excellence in tobacco research.’
“Zimbabwe’s tobacco seed development has passed through four research eras, all based on balancing the desires of growers and merchants.
“We moved from the white-mould into the tobacco mosaic era and advanced to heavy soil adaptation era to the current high yielding era,” he said.
Dr Kashangura revealed that it took 10 to 12 years to come up with a variety for sale to growers.
“A developed variety passes through three years under agronomic trials, two years under smoking trials, more years under limited release phase to satisfy the quality control protocol, before sale to growers on the open market,” he added.
Chronicling the 75-year history, he said the pre-1950 era saw growers planting importing seed, which had no disease resistance and relied on wild species to incorporate disease resistant genes in the seed.
“KE1 was the first variety with disease resistance and is orange in style, it was however, not resistant to tobacco mosaic virus. Breeding research produced KM10 in the 1980s and 1990s, a lemon-styled variety, which was resistant to tobacco mosaic virus but not to root node,” he elaborated.
Kutsaga research intensified and developed varieties, which are resistant to root node with improved yields of up to 2 000 kilogrammes per hectare, the KRK varieties.
It also produced varieties that were attached to soil types with those produced in heavy soils containing a lot of nitrogen and presenting challenges of late maturing and angular leaf spot disease.
“Lemon-styled medium to fast ripening varieties (KRK26R, KRK22 and KRK23) were produced with better yields of up to 3 000 kilogrammes. KRK26 ripens very fast such that a farmer needs to have twice the barn capacity of his/her field and where the farmer ordinarily harvests two leaves per plant, he will be picking four to six leaves,” he explained.
The 2000s era saw breeding of varieties that are slow ripening to counter the lack of adequate barn capacity challenge. The tobacco plant has lugs, leaf and tips.
“The yield in tobacco is in the leaves, it’s not in the seed bed leaves or lugs. If the leaf holds then it builds a lot of starch allowing harvest of four to five tonnes per hectare,” Dr Kashangura added.
He urged growers to ensure that they do not harvest underripe and overripe leaves but only mature leaves that would have accumulated the starch/carbohydrate required for the right weight.
Kutsaga has developed orange-styled climate-smart varieties KRK 75 and KRK 71, which thrive under drought conditions, thanks to their dense, fibrous root system.
Online Reporter