Theseus Mauruki Shambare in VICTORIA FALLS
FARMERS are set to benefit from reduced production costs and improved crop performance through biological technologies that use beneficial micro-organisms to improve soil health and protect crops against diseases.
The technologies, being explored by local researchers, were presented today at the ongoing 70th Cooperation Centre for Scientific Research Relative to Tobacco (CORESTA) Congress in Victoria Falls.
The research was conducted by independent researcher affiliated with the Tobacco Research Board (Kutsaga), Miss Debra Chamboko in collaboration with head of Plant Health and Agricultural Resilience Dr Cleopas Chinheya.
It examined the use of three beneficial fungi, Trichoderma harzianum,Trichoderma asperellum and Trichoderma asperelloides — in tobacco, maize, soybeans and groundnuts.
Miss Chamboko said farmers, particularly smallholders, needed affordable and accessible solutions to improve soil health and manage diseases caused by organisms living in the soil.
“Zimbabwe’s tobacco industry is predominantly smallholder-driven, with 85 percent of the tobacco output coming from the smallholder farmers. But these farmers, they operate in input and resource constraints.
“So there is need for a sustainable and cost-effective and also easily accessible solution because the soil health and the soil-borne pathogens remain an important challenge in this production,” she said.
Trials conducted over two growing seasons at Kutsaga in Harare and in Tete Province, Mozambique, in collaboration with Mozambique Leaf Tobacco, tested two ways of applying the beneficial fungi: soaking seeds in a prepared solution before planting and coating seeds with the fungi before sowing.
In tobacco, the treatments improved the plants’ ability to withstand diseases across four varieties, with disease suppression ranging from 39 to 62.5 percent.
They also reduced pressure from nematodes — microscopic organisms that attack plant roots — by between 10 and 71 percent.
However, the effect on yields varied among the tobacco varieties, with some recording increases while others experienced declines.
“The response to inoculation may have been dependent on the genotype of the crop, as we noticed there were varied responses to the inoculation for all the varieties,” Miss Chamboko said.
In maize, soaking seeds in the fungal solution before planting produced the strongest improvements in germination and early plant growth. The method also recorded the highest yield increases when using T asperellum and T asperelloides.
For soybeans and groundnuts, coating seeds with a combination of the three fungi produced the strongest yield responses, although the treatments did not significantly improve germination.
Miss Chamboko said the next phase would investigate combining Trichoderma with Bradyrhizobium japonicum, a beneficial bacterium that helps legumes capture nitrogen from the air and make it available to plants.
The research seeks to establish how the combination could improve soil fertility, crop productivity and the recycling of nutrients in crop rotation systems.
“The ultimate goal now is to develop a biologically supported rotation system that is productive, sustainable, nutritionally beneficial, and economically viable for the farmer,” she said.
“Microbial technologies have potential to support sustainable and efficient production in the production systems that we have.”
The researchers said further trials were necessary to identify the most effective combinations and application methods for different crops and growing conditions.
