ABSTRACT
A field experiment was conducted during the 2014 cropping season at the Teaching and Research Farm of the University of Agriculture Makurdi, Benue State to assess the growth, yield and quality of some soybean varieties in Makurdi. The experiment was conducted in a Randomised Complete Block Design (RCBD) with three replications and Treatment comprises of six varieties of soybean which were B1, B2, B4, B5, B6 and TGX 1448-2E. Samples of each of the variety were collected at the experimental site and was utilized to perform proximate analysis using standard methods at the College of Animal Science Laboratory for the determination of protein, carbohydrate and oil content. From the data collected and analyzed, it was observed that 1000 seed weight per plant and harvest index was significantly higher for B4 while variety B1 was significantly higher in terms of biomass of grain per plot, number of pods per plant and leaf area at maturity. Variety B4 and B1 are the best adapted genotypes to the Southern Guinea Savanna ecology among the five recently introduced elite varieties from Brazil. The result from the proximate analysis showed that B6 had the highest crude protein and moisture content, B2 had the highest crude fiber while variety B4 has the highest fat/oil content. Ash content was higher in B5.
CHAPTER ONE
1.0 INTRODUCTION
Soybean [ Glycine max (L.) Merrill] is the world’s leading source of oil and protein. It has the highest protein content of all food crops and is second only to groundnut in terms of oil content among food legumes (Fekadu et al., 2009; Alghamdi, 2004). The spread of soybean from its native land of origin has been mainly due to its adaptability and predominant use as a food crop for human nutrition, source of protein for animals, medicinal plant and lately as an industrial crop (Yusuf and Idowu, 2001). Traditionally, soybean is widely grown in the middle belt or the savannah zone of Nigeria (Okpara and Ibiam, 2000) but, its production has presently expanded beyond the traditional production areas of the middle belt to cover other Northern and Southern parts of the country that were otherwise considered unsuitable or marginal for soybean production (Asiegbu and Okpara, 2002).
Soybean is an industrial crop; it is also referred to as a miracle crop because of its nutritive value as a weaning food for infants and cheap source of protein for the privileged and the less privileged (Lucky Omoigui 2014).
Soybean has about 40 percent protein content and more protein-rich than any of the common vegetable plants found in Nigeria. It is a major industrial crop because soybean seeds contain about 20 percent oil on dry matter basis which is cholesterol-free (Lucky Omoigui 2014). Almost in every home, soybean is consumed in one way or the other. Soybean is not only seen as an oil plant but also used for various purposes. Among grain legumes, soybean is an economically important crop that is grown in diverse environments throughout the world.
Soybean has a tremendous potential to improve the nutritional status and welfare of the families of resource poor farmers (Sanginga, Adesina, Manyong, Ofite, & Dashiell, 1999; Obatolu, 2006). This is because it contains 42.8% high quality protein, 22.8% edible vegetable oil, 33% carbonate and a good balance of amino acids (Raw Material and Research Development Council, 2005). In addition, soybean oil is 85% unsaturated and cholesterol free when compared to other legumes and animal sources (International Institute for Tropical Agriculture [IITA], 1998). Currently, Nigeria is Africa’s largest producer of soybean, producing about 437,000 metric tons and Benue State, producing about 175, 000 metric tons, is Nigeria’s largest soybean producer (Federal Ministry of Agriculture and Water Resources [FMAWR], 2008). The utilization of soybean in local diets and local industries across Nigeria, as well as the contribution to export, has increased the demand for the crop over the years.
Grain yields of soybean cultivars are generally low in Nigeria compared to other places in the world. Yield on growers’ farms is often lower than 1000 kg/ha compared to yields greater than 2500 kg/ha in the USA (Modali, 2004), 3000 kg/ha in Brazil and greater than 3500 kg/ha in Turkey (FAO/ STAT, 2004). There is therefore a wide gap between what is currently being produced and what is needed. Increasing soybean production to meet the required quantities can best be achieved through an increase in yield per unit area, which can partly be achieved by the cultivation of high yielding improved varieties.
Soybean quality is influenced by nutrient availability and phosphorus has a positive effect upon oil and protein content (Gaydou and Arrivets, 1983).Very high soil phosphate values may depress seed protein and oil contents, or induce zinc and iron deficiencies (Weiss, 1983). Research has shown that genetic success in increasing yield and oil concentration, maintained protein concentration, but high protein cultivars tended to have relatively low oil concentration (Westgate et al. 1999; Morrison et al., 2000).
1.1 Objective
The objective of this work is to assess the growth, yield and quality of some soybean varieties in Makurdi.
