Wheat is Kenya’s second largest grown cereal crop after maize. Consumption of wheat food products has now overtaken maize across the country. Accordingly, Kenya has yet to achieve self-sufficiency in production, in fact the gap is widening. One of the main challenges in production of wheat is post-harvest losses particularly when conditions are wet during harvest. Poor prices can also dampen farmers’ morale, although prices fluctuate from year to year.
Wheat diseases pose serious challenges resulting in major losses. Some common ones in Kenya include stem rust, blotch, head smut among others. Weed control is also of major importance, as weeds will strangle young wheat crop very quickly. Despite these challenges, wheat farming can be very rewarding, provided production is maximized, and quality is maintained. A healthy crop harvested at the right time will fetch higher prices in the market, which is undersupplied.
Wheat does best in medium to high altitude, depending on the variety. It also prefers medium rainfall and cool temperatures. The soil should be well drained (loamy), medium to slightly acidic Ph, and fertile. Areas where wheat is grown in Kenya include Narok, Nakuru, Uasin Gishu, Trans Nzoia, as well as Nanyuki. Narok is the leading area of production, followed by Nanyuki. The planting season starts from February to early April, during the long rains. Highland wheat (and Barley) is grown in Mau Narok and Uasin Gishu. The planting season there starts much later, July to August, as the long rains persist for longer. Choice of variety depends on area of production, and resistance to disease. These include varieties such as Pasa, Kenya chirika, Mbuni, Kenya kwale, Kenya popo, Kenya fahari, Kenya kongono, Kenya Nyambu, Kenya Nyangumi, Kenya paka, Kenya kulungu, Kenya nungu, Kenya Tembo, Kenya Mbweha, Duma, Ngamia, Mbega, Ks farasi, Ks Mwamba. These have been bred by KALRO, and are generally available from KFA, or from registered seed farms within the planting zones.
Growers will frequently process their own seeds from earlier crops, rather than buy new seed stock. Quality can generally persist for up to 3, 4 seasons without undue deterioration. However, disease resistance can be compromised after 2 plantings. Treating with PROTREAT and RODAZIM at 2ml per kg of seed, (2 ltrs of each mixed in 6-8ltrs of water for 100 kgs of seed) will protect seeds from insect and disease infection for up to 6 weeks after planting.
Wheat requires a fine planting bed for uniform germination. The land should be well ploughed and harrowed. It should be free from growing weeds and weed seeds, to prevent strangulation of the young crop. It is recommended to first apply a pre-emergence herbicide (Glyphosate) followed by thorough ploughing and harrowing, at least 4 weeks before planting. This will ensure the land does not have fresh compost (plant material that is not fully rotten) during planting, which is detrimental to germination and early plant growth.
Planting is best done using a seed drill. Planting spacing should be 15cm between rows. The seed drill and speed of planting should be set to deliver 120 to 140 kgs per Ha. This is the optimum seed rate. DAP Fertilizer can be applied at the rate of 200-250kgs per Ha, depending on the soil analysis reports.
For best results, seeds should be pre-treated with PROTREAT, RODAZIM, and AFRIKELP (2ltrs per 100kgs seeds). This will ensure protection against insect pests such as wheat aphid, which attack early and are vectors for very serious viral diseases. The AFRIKELP will stimulate strong germination and root establishment, giving the wheat an early start over the weeds, thus a better chance of survival and higher production.
Weed management is a key activity in wheat. Care should be taken to prevent weeds from overtaking the crop, as this will reduce production significantly. Post emergence weed control is best done between 3rd leaf and tillering stage (between 3-5 weeks after germination). Weeds should be targeted when they are growing strongly, and before they are mature. It is difficult and expensive to control weeds which have grown up to flowering stage. For Grass weeds, including rye grass, canary grass, wild oats, etc., treat with TWIST 100EC (750ml to 1ltr per Ha).
For broad leafed weeds, apply Pro2.4D 720SL (1-1.5 Ltrs per Ha). These can also be combined (mixed) at half rates each for total protection. This combining will also reduce the cost of production. One application should be enough if the crop is growing as required.
Wheat requires fertile soils for optimum growth. Soils should be high in nitrogen, phosphorous and potassium. Kenya’s soils are often deficient in Sulphur and Copper which are very important for wheat. The application of fertilizers should be dictated by the stage of crop growth. During planting, DAP at 200 to 250 kgs per Ha is recommended. Quickly available Nitrogen is especially important during tillering, stem extension and ear emergence. Therefore, instead of topdressing with granular fertilizers, it is recommended to apply HARMONY, 300ml per Ha at Week 2, repeated at week 5, Week 7 and Week 10 where possible, or at least once every month.
Further application of Soluble copper and sulphur minerals is recommended during ear emergence (week 9, 10). These are crucial for proper ear formation and growth, and often are deficient in soils. However, DO NOT mix these with HARMONY, or any other foliar or pesticide.
PROTECTION AGAINST PEST AND DISEASE:
Proper crop rotation is important in reducing pest and disease incidence. You should avoid alternating crops with maize, barley, oats, Rhodes grass, or any other member of the Grass crop family. Legumes (including canola) are the best choice, followed by potatoes, cabbages or other vegetables.
Aphids are the most important insect pest. These can cause huge losses to the crop, and they are vectors for viral diseases. Aphids can be controlled by Application of JACKPOT 5EC, or ALPHASIN at 300ml per Ha per spray on the first sign of attack, and repeated 5 days later. This will also control Army worms and Pink borers, and Wire worms, all of which can be potentially destructive. JACKPOT 5EC and ALPHASIN have low toxicity to animals and humans and are therefore safe to use.
Termites can be a problem at times. If the farm is prone to termites, it is advisable to apply IMAXI at 300 ml per Ha during planting. It can be sprayed onto the planted field in areas where termites are known to emerge. One spray should protect the crop till harvest. Additionally if the problem is recurring, it is advisable to identify the nest where the termites originate from and treat the nest with METRO 25ml/20ltr mix. This is done by cutting off the heads of the chimneys in an ant hill, and applying METRO mixture at least 1 Litre per hole.
The most serious wheat diseases are stem and leaf rust, blotch, and head smut. Smut has been largely controlled through breeding of resistant varieties. Ensure the seed you use is free from smut by using certified seed. Rust and Blotch can be controlled by proper field hygiene, and early application of STAGE 250EW, at 500ml per Ha. It is best applied as a preventative measure at flag leaf and ear emergence, when crop is most susceptible to attack. Mixing STAGE with HARMONY gives excellent results, as HARMONY increases the efficacy of the fungicide, while increasing crop nutrition. If the rust attacks during rainy weather, repeat the spray after 7 to 10 days, and then if necessary, alternate this after 7 -10 days with an azoxystrobin based fungicide, together with HARMONY. This should be enough to clear the disease.
When the wheat has reached full maturity, the kernel becomes difficult to divide with a thumbnail, cannot be crushed between fingernails, and can no longer be dented by a thumbnail. It is ready for harvest when the kernels have achieved maximum weight and suitable moisture level. An experienced farmer can determine this by biting the kernels. Harvest is best done by a combine harvester. To fetch the highest price, the wheat must meet high quality standards. These include high weight/volume ratio, low moisture content, and optimum protein content. Buyers will assess wheat for these parameters and pay according to grade. In order to achieve these quality specifications, the farmer should do his best to ensure the crop receives the correct nutrition and water requirements, and reduce insect and disease pressure.