How maize seeds are bred to boost food security

By Maore Ithula

Because Kenya’s agriculture is rain-fed, local breeders for maize seeds mould their research to fit into rain patterns in various parts of the country.

For this reason, breeders concentrate crossbreeding efforts on developing maize lines that do well in each of the four ecological zones, experts say.

Mr James Nderitu, the Kenya Seed Company’s technical sales adviser, says Kenya can be divided into four climatic zones: Highlands (Mt Kenya region, Kericho, Kitale and Eldoret; medium altitude and transitional zones (Eastern, Nairobi, Kiambu), dry land areas (Ukambani, North Eastern Province and northern Kenya) and the lake, Coast region and low-lying areas (Nyanza and Coast Provinces).

Nderitu says seeds are developed according to the rainfall each region receives annually.

Mr Robert Musyoki, Simlaw Seeds’ research officer, concurs. He says: "Because heights above the sea level determine climates in specific areas, packages of seeds developed by any breeder, must be clearly coded to depict the altitude status of the area for which the seed is developed."

Examples are the H500 and H600 series of maize seeds, he says. The letter H, notes Musyoki, stands for highlands while 500 and 600 are indications that seeds will achieve optimum performance if they are grown in farms located more than 5,000ft and or 6,000ft above sea level. The H500 series is meant for the medium altitude and transition zones, while the H600 is for the highlands, says Musyoki.

"For the lake and coast regions, there is the PH1, 2, 3 and 4. The letters PH stand for Pwani Hybrid. The DH01, 02, 03 and 04 are designed for the dry lands," says the researcher.

Erratic climates

This explicit branding is a reserve for Kenya Seeds and Simlaw Seeds which develop seeds for various crops locally. Other companies sell imported seeds aimed at meeting erratic international climates.

They are then tested by the Kenya Plant Health Inspectorate Services (Kephis) to ensure they are able to meet the needs of local ecological zones.

Nderitu says Kenya Seeds and Simlaw Seeds conduct breeding in stations in specific areas where they (seeds) are supposed to be grown.

For instance, the Mtwapa breeding station takes care of the Coast and lake region, Kiboko for Lower Eastern; Embu for medium altitudes while Kitale, Muguga and Lanet serve high and medium altitudes.

Musyoki says seeds for crossbreeding are identified through their special traits that include, taste, yield levels, adaptability to weather, resistance to diseases and pests and time of maturity. Others are, cob size and shape and post-harvest conversion like density, he says.

When the preferred strain(s) is chosen, the researcher says, breeding starts with the help of selected farmers. Mature maize cobs are harvested and sorted out before shelling. Cobs that are not true to characteristics stated above are discarded.

Maize processing

Selected cobs are dried to the optimum moisture content of 13 per cent. The kernels are then removed manually, leaving the bottom and the top parts of the cob to avoid extremities in seed character.

Through a sieve, kernels are sorted into three grades. The ‘medium flat’ type are fit for machine planting, the ‘large flat’ can be planted using both machines and the hand while the ‘hand-planting’ lot are specifically for manual planting.

This pattern of grading is conducted on each of the four categories of seeds, based on the ecological zones they are destined to be grown.

The last stage before maize seeds find their way into the shelves of ‘agro vet’ stores, is dressing which is conducted after Kephis has established that the seeds really meet some set quality standards that include 98 per cent rate of germination, maximum moisture content of 13 per cent, absence of disease and purity.

They are then dressed in a mixture of fungicide, insecticide and dye before they are packed in units of one, two, 10 and 25 kilogrammes. The packet must be marked clearly which grades of each of the four categories of seeds they contain, the experts say.