By Gift Briton
Researchers have found out that high-density planting and top-dressing during flowering could increase the yield and grain protein content of cowpea.
This is according to a study done by International Institute of Tropical Agriculture(IITA) and the Consultative Group on International Agricultural Research (CGIAR) focusing on establishing a simple method for increasing the yield and protein content of the crop.
According to the researchers, cowpea (Vigna unguiculata), is an important source of protein and livelihood for many people in the African region with west Africa alone accounting for more than 80% of annual world production. However, they note that its yields per unit area and the seed protein content need to be increased to meet the protein demands.
To achieve this, they carried out a study to investigate the effects of top-dressing timing on cowpea yield, the seed nitrogen content as well as the effect of the planting density on the crop’s yield in farmers’ fields in three different regions of Burkina Faso.
During the investigation, three planting density plots—normal, high, and super high —were established in the different regions, characterized by their annual rainfall. The north region was semi-arid (annual rainfall of 520 mm), the central region was also semi-arid (an annual rainfall of 780 mm) and the south region was sub-humid (annual rainfall of 1175 mm).
The result showed that high-density planting and top-dressing during flowering could increase the yield and grain protein content of cowpea in different agroecological zones across different regions in Burkina Faso. Under such approaches, the yield significantly increased by as much as 214.5% and applying top-dressing when the plants started flowering increased the seed protein content by up to 24.4%.
According to the researchers, cowpea yield can be easily improved even when farmers have no access to fertilizer, adding that even if the cowpea yields for any individual farmers do not improve dramatically, the effects of high density planting could greatly impact national or regional production.
Meanwhile, high density planting is the accommodation of the maximum possible number of plants per unit area to get the maximum possible profit.
In addition, the researchers advised farmers to evaluate the soil type, soil fertility, and varieties of cowpea they use in their locations to adapt to the developed techniques, noting that that simple management practices could improve the income and nutritional status of populations through increased protein intake in developing countries.
According to Haruki Ishikawa, lead researcher and Plant Physiologist at IITA, “Our findings could contribute to achieving stable and sustainable food production in West Africa.”
Cowpea is a food and animal feed crop grown in the semi-arid tropical areas with 25% grain protein content and several vitamins and minerals. The plant tolerates drought, performs well in a wide variety of soils, and being a legume, it can replenish low fertility soils when the roots are left to decay. In addition to its ability to tolerate shade, enabling it to be cultivated with other crops, cowpea also grows and covers the ground quickly thereby preventing erosion.
According to IITA, cowpea’s high protein content, its adaptability to different types of soil and intercropping systems, its resistance to drought, and its ability to improve soil fertility and prevent erosion makes it an important economic crop in many developing regions.
Moreover, all parts of the cowpea crop are used as all are rich in nutrients and fiber. In Africa, humans consume the young leaves, immature pods, immature seeds, and the mature dried seeds. The stems, leaves, and vines serve as animal feed and are often stored for use during the dry season with more than four million tons of the crop being consumed worldwide and 387,000 tons consumed in Africa.