International Institute Of Tropical Agriculture Research Articles

Genetic Analysis of Grain Yield of IITA and CIMMYT Early‐Maturing Maize Inbreds underStriga‐Infested and Low–Soil‐Nitrogen Environments

ABSTRACTBreeding maize (Zea maysL.) hybrids resistant toStrigaand tolerant to low soil nitrogen (low‐N) will reduce grain yield losses due to stresses in West Africa (WA). Studies were conducted to determine if selection forStrigaresistance and/or drought tolerance in early‐maturing maize populations improved low‐N tolerance in hybrids derived from selected inbreds from International Institute of Tropical Agriculture (IITA) and International Centre for Maize and Wheat Improvement (CIMMYT) underStriga‐infested, low‐N and optimum environments in Nigeria. One hundred and fifty hybrids developed from crosses involving 30 lines using North Carolina Design II plus six checks were evaluated at two locations each under low‐N, artificialStrigainfestation, and optimum environments for 2 yr. Lines with combined resistance or tolerance toStrigaas well as low‐N were identified.Striga‐resistant– as well as low‐N–tolerant hybrids with outstanding performance under both stress environments could be obtained through the accumulation of favorable alleles for resistance or tolerance in both parental lines. Although selection forStrigaresistance and/or drought tolerance resulted in improved performance of genotypes under low‐N, it is important to test genotypes under low‐N to identify those with outstanding performance under the target stress. ENT 11 × TZEI 4 and TZEI 65 × ENT 11 were identified as the most stable and high‐yielding hybrids.

English

Nitrogen and potassium are key nutrients for optimum productivity in Musa species. In this study, optimum doses of N and K were determined for two plantain genotypes. The growth and dry matter yield (DMY) of ‘PITA 24’ (a hybrid plantain of the International Institute of Tropical Agriculture) and a landrace, ‘Agbagba’ were evaluated on factorial doses of N (0, 200, 400 and 600 kg.ha-1) and K2O (0, 300, 600 and 900 kg.ha-1). The nutrient use efficiencies of the applied nutrients were also studied. Analysis of variance showed that fertilizer combination significantly (p<0.05) influenced the genotype performance and genotype-by-fertilizer interaction effects. Growth and DMY in both genotypes were superior where both nutrients were applied together. ‘PITA 24’ maintained a better growth, higher DMY, and greater efficiency of nutrient use than ‘Agbagba’. Both genotypes had the best growth where N was applied at 200 or 400 kg.ha-1 in combination with 300, 600 or 900 kg.ha-1 of K2O. The control plants were the poorest. Agronomic efficiency (AE) of applied K+ was high at N200K300, N400K300, and N600K300; similarly, AE of applied N was superior at N200K600, N200K300, and N200K900. The partial factor productivity from the applied nutrients was highest at N200K300, suggesting that it was most economical to grow plantain with 200 kg N and 300 kg K2O ha-1. For optimum performance of plantains in the humid tropics of southeastern Nigeria, results from the study suggest the combined application of 200 to 400 kg N and 300 to 600 kg K2O per hectare, per annum. Key words: Plantains, dry matter yield, nutrient use efficiency.

Effect of Tillage on the Growth and Yield of Cowpea Varieties in Sudan Savanna Agroecology of Northern Nigeria

Field study was conducted during the rainy seasons (July-November) of 2007, 2008, 2009 and 2010 at the Research Farm of the International Institute of Tropical Agriculture (IITA) Minjibir, Kano State, Nigeria; to compare responses of six cowpea varieties to tillage. The treatments consisted of tillage systems (zero tillage, flat tillage and ridge tillage) as the main plot and cowpea varieties (IT89KD-391, IT90K-277-2, IT97K-461-4, IT97K-499-35, IT98K-131-2, and IT98K-506-1) as the sub-plot. The treatments were arranged as split plot laid out in a randomized complete block design with four replications. Zero tillage was significantly superior in influencing days to maturity, canopy height, intercepted Original Research Article Ewansiha et al.; ARRB, 5(3): 275-284, 2015; Article no.ARRB.2015.030 276 photosynthetic active radiation (IPAR) and leaf area index but not total dry matter and grain yield of cowpea. A positive and significant association was recorded for days to physiological maturity and canopy height across the tillage systems with a correlation coefficient of ≤ 40% for days to maturity and ≥50% for canopy height. Though flat tillage showed a positive correlation with intercepted photosynthetic active radiation (IPAR) and leaf area (LAI), but this association was not significant. However, ridge tillage showed a positive and significant correlation with IPAR and LAI (r =0.378*** and 0.384***). All the tillage systems showed a high and significant positive correlation with cowpea dry matter and fodder yield (r= 0.54*** to 0.77***). Across varieties, grain yield was better with flat tillage than zero and ridge tillage systems, with 10% yield advantage over the two. Zero and ridge tillage were similar in their effects on grain yield. Except for IPAR, LAI and total dry matter (TDM), the interaction effect of cowpea varieties and tillage systems was significant. Our result point to the fact that extensive soil tillage (especially, conventional tillage) may not be necessary for cowpea production in this agro-ecology with a high percentage of sand and a sandy loam as soil textural class. Following our result, we may recommended varieties for the different tillage systems as follows: IT98K-131-2, IT97K-461-4, IT90K-277-2, IT98K-506-1 (grain) and IT89KD-391/IT97K-4614 (best for fodder) for zero tillage system; IT90K-277-2, IT97K-499-35, IT98K-131-2 and IT98K506-1(grain) and IT89KD-391/IT97K-499-35 (best for fodder) for flat-tillage; IT98K-131-2, IT90K277-2, IT98K-506-1 and IT97K-464-4(grain) and IT90K-277-2/ IT89KD-391 (best for fodder) for ridge tillage).

Evaluation of Potential Allelopathic Relationship between Velvet bean (Mucuna cochinchinensis (Lour.) A. Chevand Speargrass (Imperata cylindrical (L.) Raeushel) with Selected Methods

Velvet bean [Mucuna cochinchinensis (Lour.) A. Chev] has been reported to smother the growth of Speargrass [Imperata cylindrical (L) Raeushel.] through competition and potential allelopathic effect on speargrass. Greenhouse experiments involving three methods were conducted at International Institute of Tropical Agriculture (IITA), Ibadan Nigeria in 2009. The aim of the trials was to establish if mucuna Original Research Article Bernard and Udensi; JAERI, 3(3): 89-96, 2015; Article no.JAERI.2015.036 90 exhibits allelopathic effect on speargrass, besides smothering effect. These methods included: (1) Mucuna fresh parts[(Leaves (L), leaves + vine (L+V), vine(V) and roots (R)] incorporation into pot planted to speargrass rhizome and a control pot without mucuna part incorporation; (2) Mucuna plant part extracts (of leaves, leaves +vines, vines and roots) and control with ordinary water; and (3) Mucuna seed and speargrass rhizome interplant (One mucuna seed-interplant, Two mucuna seeds interplant and Three-mucuna seeds interplant). Results showed that every mucuna part has the potentials of being allelopathic to speargrass. Incorporating mucuna parts into pot with speargrass reduced both speargrass shoot height and number by ≥ 20% and ≥ 50% respectively. Similarly mucuna parts extract on the average, reduced shoot and rhizome biomass by ≥ 60% and ≥ 50% respectively when compared to the control. The pot interplant method on the average showed a reduction of speargrass shoot and rhizome biomass by ≥ 20% and ≥ 16% respectively. The effect of speargrass and mucuna interplant on speargrass shoot height was not variable between the speargrass-mucuna interplant and the sole speargrass control except at 12 WAP. This investigation revealed that mucuna also exhibits allelopathic effect on speargrass, and this could serve as a bio-control method for speargrass. All the mucuna parts studied have the potentials of exhibiting allelopathy effect on neighboring and susceptible plants. The allelopathy effect appears to be greater with the leaves or the vines or both.

Effect of Staking and Non-staking Systems on Disease Severity, Yield and Quality Attributes of Yams (Dioscorea alata)

Aims: The aim of this study was to evaluate the effect of staking and non - staking systems on disease severity, yield and quality attributes of yams . Methodology: High c osts and lack of planting materials, labour, staking and inappropriate knowledge on production techniques are major constraints of yam production in Sierra Leone. A total of seven promising hybrid genotypes of yams from International Institute of Tropical Agriculture and one local cultivar, Pulli, were evaluated for yield, reaction to local pest and disease and desirable market traits during 2011 and 2012 in three agro - ecological zones of Sierra Leone. The experiment was laid out in randomized complete bloc k replicated thrice at the experimental

Proteomic Quantitative UV Absorption Spectrum Analysis of Effect of Heat Stress on Protein Extract from Cowpea Seed (Vigna unguiculata (L) Walp)

Aim: Proteomic quantitative UV absorption spectrum analysis was used to study the effect of heat stress on protein extract from cowpea seeds (Vigna unguiculata (L) Walp). Study Design: Protein extracts were obtained from 9 cowpea accessions obtained from GeneBank of International Institute of Tropical Agriculture in January 2014. Each protein extract was divided into four batches out of which three batches were subjected to different temperature treatments and incubation at 37°C, 60°C and 100°C for 1 hour and the remaining one batch served as control. Protein content in each control protein extract and 37°C, 60°C and 100°C treated protein extracts from each of the 9 cowpea samples were determined at 280 nm using bovine serum albumin standard curve. Place and Duration of Study: Biochemistry Unit, Department of Chemical Sciences, Afe Babalola University Ado Ekiti, Nigeria between January 2014 and June 2014. Methodology: A200-A960 UV wavelengths absorption spectrum analysis was carried out on control protein extract and 37°C, 60°C and 100°C treated protein extracts respectively from each of the 9 cowpea samples. In order to establish the relationship between protein extracts (control) and protein extracts heat treated (37°C, 60°C, and 100°C), cluster analysis of optical density (OD) data was carried out using numerical taxonomy and multivariate analysis system. Results: The protein content (control) in Vigna unguiculata (L) Walp was between 8.4 and 10.8 mg/ml (10.5-13.5%) in seed, while protein content (heat treated) in Vigna unguiculata (L) Walp was between 8.9 and 9.5 mg/ml (11.2-11.9%), 8.7-9.5 mg/ml (10.9-11.9%), 9.0 and 11.8 mg/ml (11.3- 14.7 %) in heat treatments of 37°C, 60°C, and 100°C respectively. The protein UV absorption spectra of control protein extract and 37°C, 60°C and 100°C treated protein extracts from each cowpea accession were generally different due to differential UV wavelength protein absorption. Cluster analysis of absorbance spectra optical density values revealed five clusters (cluster 1, cluster 2, cluster 3, cluster 4, and cluster 5) among control protein extracts and protein extracts heated at 37°C, 60°C, and 100°C. Cluster1 was made up of protein extracts heated at 37°C and 60°C, while cluster2 and cluster3 constituted closely related protein extracts heated at 37°C and 100°C respectively. Cluster4 was typical of control protein extracts, while cluster5 was made up of distinct protein extracts heated at 100°C. Conclusion: Heating protein extracts at 37°C, 60°C, and 100oC has altered proteomic diversity in different cowpea accessions and this could make protein extraction more difficult with implications on protein properties

Characterization of New Quality Protein Maize (QPM) Varieties from a Breeding Program: Analysis of Amino Acid Profiles and Development of a Variety-Diagnostic Molecular Marker

Aims of the Study: This study was to determine the amino acid profile of two newly developed quality protein maize varieties and to develop variety-diagnostic molecular markers. Methodology: Two new maize varieties, named MUDISHI 1 and MUDISHI 3 have been developed by breeders and farmers using the participatory breeding approach. Total protein and amino acid profiles of the two new lines were compared to their respective parental population and a locally Original Research Article Nkongolo et al.; BBJ, 6(3): 101-112, 2015; Article no.BBJ.2015.032 102 released genetically improved normal maize variety. Maize accessions from the DR-Congo breeding program were analyzed using ISSR primers. Variety-diagnostic markers were identified and characterized. Results: Protein analysis data revealed that MUDISHI 1 and MUDISHI 3 are QPM varieties that are distinct from their original population, Longe 5 QPM from NARIUnganda and DMR-ESR-W-QPM from the International Institute for Tropical Agriculture (ITTA, Ibadan), respectively. Lysine content in MUDISHI 1, and MUDISHI 3 were 3.5 g and 3.6 g of lysine / 100 g, respectively, which represents a significant increase of 20% and 23% over the genetically improved normal maize variety (Salongo 2) that is currently released. There was a significant increase of 25% of tryptophan and 33% of methionine in MUDISHI 3 compared to its parental variety while the amount of lysine was similar for the two varieties. There were 10% and 15% decrease of lysine and tryptophan, respectively in MUDISHI 1 compared to its original parent Longe 5 QPM. Genomic DNA was extracted from different maize varieties. One ISSR diagnostic-marker of 480 bp that was identified was unique to the QPM variety MUDISHI 3. This sequence was converted to a sequence characterized amplified region (SCAR) marker using a pair of designed primers. This SCAR sequence was not specific to MUDISHI 3 as it was present in all the varieties tested. Conclusion: The newly developed varieties are typical QPM lines. The development of an ISSR diagnostic marker indicates that it is possible to develop a molecular breeding program involving QPM and normal varieties.

Genetic Analysis of Effect of Heat Stress on Genomic DNA from Cowpea (Vigna unguiculata (L) Walp.)

Aims: Genetic analysis was used to study the effect of heat st ress on young seedlings of cowpea ( Vigna unguiculata (L) Walp.). Study Design: Four different colors of cowpea seeds (white, dirty w hite, deep brown and light brown) were obtained from GeneBank of International Institute of Tropical Agriculture (IITA) Ibadan, Nigeria. Seeds from each of the cowpea four colors we re first pre-germinated and young seedlings subjected to DNA extraction. Extracted DNA subjected to different temperature treatments at 75°C and 100°C for one hour and control not heated. Place and Duration of Study: Department of Chemical Sciences Afe Babalola University Ado Ekiti, Nigeria between January 2015 and June 2015. Methodology: UV wavelength absorption spectrum analysis (A 200 – A 960 ) was carried out on control DNA and DNA heated at 75°C and 100°C respectively. Cl uster analysis of optical density (OD) data was carried out to establish the relationship between co ntrol DNA and heat treated DNA (75°C and 100°C). Results: DNA concentrations of Vigna unguiculata (L) Walp. were between 0.40 to 1.15 mg/ml, 0.33 to 0.84 mg/ml, and 0.26 to 0.89 mg/ml for control a nd heat treatments of 75°C and 100°C respectively. DNA UV absorption spectra of control and heat treatments of 75°C and 100°C were generally different due to differential UV wavelengt h absorption. Cluster analysis revealed three different clusters (cluster 1, cluster 2 and cluster 3) among control DNA and heat treated DNA. Cluster 1 comprised of V1-control, V1-75°C and V1-10 0°C, with V1-75°C and V1-100°C having similar characters. Cluster 2 was made up of V4-control, V4-75°C and V4-100°C, with V4-75°C and V4-100°C having the same characters. Cluster 3 was largel y characterized by dissimilar DNA extracts of V3-75°C, V2-control, V3-100°C, V2-100°C, V 3-control and V2-75°C. Conclusion: Genetic diversity among individual Vigna unguiculata (L) Walp. accession DNA as obtained in this study could possibly be as a result of variations in heat tolerance among dissimilar cowpea genomic compositions

Evaluation of levels of select toxic metals in commonly used herbal medicines in Benin city, south-south Nigeria

Background : Herbal medicine has been gaining growing attention as medicinal plants are now the major remedy to diseases in some places, especially in Africa. Some herbal preparations are made without standard manufacturing and safety standards, a practice that makes the products susceptible to contaminants which may include toxic metals. Even at low concentrations or levels of exposure, toxic metals have also been reported to pose health risks to man. Aim : To evaluate the levels of toxic metals in herbal medicines commonly prepared and used in Benin City, Edo state, Nigeria. Materials / Methods :Herbal medicines (n=8) were purchased from on-the-street vendors and evaluated for levels of five toxic metals (Lead, Nickel, Mercury, Cadmium and Arsenic).Analysis of toxic metals was carried out in the analytical services laboratory of the International Institute of Tropical Agriculture (IITA) Ibadan using Inductively Coupled Plasma Mass Spectrometry. Results :Lead (mg/L) respectively detected in the eight sampled herbal preparations were 0.025, 0.022, 0.092, 0.088, 0.052, 0.074, 0.051 and 0.092; while nickel levels (mg/L) were 0.075, 0.066, 0.277, 0.265, 0.153, 0.158, 0.029, and 0.052;and Levels of cadmium in mg/L detected were 0.014, 0.013, 0.052, 0.50, 0.029, 0.029, 0.153 and 0.277. In addition, Levels of mercury (mg/L) observed in the respective herbal samples were 0.035, 0.031, 0.129, 0.124, 0.071, 0.072, 0.071 and 0.129; and arsenic (mg/L) levels as observed were 0.002, 0.002, 0.007, 0.006, 0.004, 0.004, 0.004 and 0.007. Conclusion : Data obtained from this study indicate that the herbal preparations studied contain detectable amounts of toxic metals and by implication, the frequent and unorthodox use of these herbal preparations may increase the body burden of these metals which have been reported to be toxic at any level of exposure. Key Words : Herbal medicine, Medicinal plants, Contaminants, Toxic metals.

Comparison of Physicochemical Properties of Soils under Contrasting Land Use Systems in Southwestern Nigeria

Soil physicochemical properties were determined for soils under cropland and forest at the headquarters of the International Institute of Tropical Agriculture in Ibadan, Southwestern Nigeria to examine the 30-year effects of different land use on the fertility of five soil series toposequences underlain by a Basement Complex. The cropland had been under cultivation for 30 years, during which mainly maize and yams had been cultivated in rotation with application of chemical fertilizer and intermittent fallow, while the forest had secondary vegetation that had been regenerated during a 30-year period under protection. The findings for cropland indicated an accumulation of available phosphorus and exchangeable potassium, soil compaction and slight depletion of topsoil organic carbon content; and the findings for forest indicated soil acidification and accumulation of exchangeable Ca at the surface soil horizon. These findings suggest the possibility of maintaining soil fertility with a long-term intensive and continuous crop farming system in kaolinitic Alfisol soil over the inland valley toposequences of tropical Africa. Discipline: Soils, fertilizer and plant nutrition Additional key words: continuous cultivation, forest restoration, maintain soil fertility, IITA Present address: 4 Faculty of Life and Environmental Science, Shimane University (Matsue, Shimane 690-8504, Japan) *Corresponding author: e-mail wakatuki@life.shimane-u.ac.jp Received 10 February 2014; accepted 6 April 2015. Introduction Soil degradation and fertility depletion are the fundamental reasons for the decline of per-capita food production, hunger and malnutrition in Sub-Saharan Africa (Sanchez et al. 1997). It is estimated that the soils in this region have suffered an annual loss of 22 kg N ha1, 2.5 kg P ha1, and 15 kg K ha1 as a result of low input farming systems for subsistence such as traditional slash-and-burn practices over the past 30 years (Smaling et al. 1997). This annual loss is equivalent to US $4 billion in fertilizer (Sanchez 2002). The longer cultivation period and shortened fallow duration under ever-increasing demographic pressure have been threatening the productivity and sustainability of the traditional farming systems. Viable alternatives to these systems are required in the transition from traditional shifting cultivation to semi-permanent systems through the use of fertilizers. Soil fertility management is key to the sustainability of prolonged, semi-permanent farming systems that enable cropping intensification. Sanchez et al. (1982, 1983) documented an improvement in pH, exchangeable Ca and available P of soil in a highly weathered red soil (Typic Paleudult) of the Amazon Basin during an 8-year period of consecutive cultivation after forest clearing as a result of the application of chemical fertilizer (annual rates: 80100 kg N ha1, 25 kg P ha1, 80-100 kg K ha1). In contrast, Juo and Lal (1977) and Juo et al. (1995a, 1995b, 1996) found a declining trend in the same soil properties and crop productivity in a kaolinitic Alfisol (Oxic Kandiustalf) of tropical Nigeria during a 10to 18-year period of consecutive cultivation despite continuous application of the

Identifying and developing maize germplasm with resistance to accumulation of aflatoxins

Efforts to identify maize germplasm with resistance toAspergillus flavus infection and subsequent accumulation of aflatoxins were initiated by the US Department of Agriculture, Agricultural Research Service at several locations in the late 1970s and early 1980s. Research units at four locations in the south-eastern USA are currently engaged in identification and development of maize germplasm with resistance toA. flavus infection and accumulation of aflatoxins. The Corn Host Plant Resistance Research Unit, Mississippi State, MS, developed procedures for screening germplasm for resistance toA. flavus infection and accumulation of aflatoxins. Mp313E, released in 1990, was the first line released as a source of resistance toA. flavus infection. Subsequently, germplasm lines Mp420, Mp715, Mp717, Mp718, and Mp719 were released as additional sources of resistance. Quantitative trait loci associated with resistance have also been identified in four bi-parental populations. The Crop Protection and Management Research Unit and Crop Genetics and Breeding Research Unit, Tifton, GA, created a breeding population GT-MAS:gk. GT601, GT602, and GT603 were developed from GT-MAS:gk. The Food and Feed Safety Research Unit, New Orleans, LA, in collaboration with the International Institute for Tropical Agriculture used a kernel screening assay to screen germplasm and develop six germplasm lines with resistance to aflatoxins. The Plant Science Research Unit, Raleigh, NC, through the Germplasm Enhancement of Maize (GEM) Project provides to co-operators diverse germplasm that is a valuable source of resistance toA. flavus infection and accumulation of aflatoxins in maize.

Occurrence of Cucumber mosaic virus Subgroups IA and IB Isolates in Tomatoes in Nigeria.

Tomato (Solanum lycopersicum L.) is a major economic crop consumed globally in fresh or processed forms. During a routine field survey of major tomato-producing areas of southwestern Nigeria in May/June 2013, tomato plants cv. Roma VF showing virus-like symptoms including stunting, chlorosis, and narrowing of leaf blades were observed in 10 farmers' fields with varying levels of incidence averaging ~27%. Moderate to high aphid infestations were also observed in affected fields, and fruit production was significantly impacted based on visual observations. Since symptoms observed on affected plants are similar to those described for Cucumber mosaic virus (CMV) infection in tomato (5), leaf tissue samples collected from a total of 92 tomato plants across 10 commercial farms were subjected to antigen coated plate (ACP)-ELISA essentially as described previously (2). In ACP-ELISA using a CMV polyclonal antibody, 24 of the 92 samples (26.1%) derived from 7 of the 10 survey locations spread across Oyo, Ogun, Ekiti, and Osun states of southwestern Nigeria tested positive for CMV. Based on the ACP-ELISA results, one randomly selected sample from each of the CMV-positive survey locations, seven samples in total, was subjected to total nucleic acid extraction (1) followed by one step-single tube RT-PCR using primers CMV1/CMV2 and conditions described previously (4) with appropriate virus-positive and -negative controls. A ~500 bp DNA band was amplified from these seven ACP-ELISA-positive samples, thus confirming the presence of CMV. To further confirm these results and to enable molecular typing of CMV isolates from southwest Nigeria, the amplified DNA fragments were precipitated with the addition of 70% ethanol and centrifugation and directly sequenced using the ABI 3130xL Genetic Analyzer (Applied Biosystems, California) at the Bioscience Center of the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. Following the removal of primer- and 3'UTR-specific sequences, the remaining 366-bp partial CP-specific sequences (GenBank Accession Nos. KM091952 to 58) and corresponding sequences of global CMV isolates obtained from GenBank were subjected to multiple alignments using the MEGA 6.0 software. This analysis showed that tomato-infecting CMV isolates from southwest Nigeria shared 91.6 to 99.4% and 94.9 to 99.1% nucleotide (nt) and amino acid (aa) identities among themselves and 91.6 to 98.0% and 94.1 to 98.3%, 89.4 to 94.1% and 93.2 to 98.3%, and 75.2 to 78.8% and 84.0 to 87.3% with corresponding nt and aa sequences of representatives of CMV isolates belonging to subgroups IA (D10538), IB (AB008777), and II (M21464), respectively. Maximum likelihood phylogenetic analysis revealed the clustering of four and three CMV isolates obtained in this study into subgroups IA and IB, respectively, with >70% bootstrap support. CMV has been detected in tomato seeds (3) and its very wide host range includes cultivated crops and weed species (5). It is therefore plausible that contaminated seed lots and alternative weed and crop host plants serve as sources of CMV inoculum to cultivated tomato in affected farms. Although CMV has been reported from tomato from several countries worldwide, to our knowledge, this is the first empirical evidence for the occurrence of CMV subgroups IA and IB in cultivated tomato in Nigeria.

3D Agro-ecological Land Use Planning Using Surfer Tool for Sustainable Land Management in Sumani Watershed, West Sumatra Indonesia

3D Agro-ecological Land Use Planning Using Surfer Tool for Sustainable Land Management in Sumani Watershed, West Sumatra Indonesia

English

This paper investigates the determinants of adoption of improved cassava varieties in south- western Nigeria. The data come from a farm household survey of 841 households selected using a three-stage stratified random sampling procedure. The data collection was conducted in 2011 by the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. Empirical estimates of a Double-Hurdle model revealed that adoption increases with the age of the household head and is influenced by the gender of the household head, hired labour, cultivated land, and access to credit. The results further showed that the intensity of adoption is influenced by hired labour and farm size; access to information about the improved cassava varieties is determined by the age, gender, and level of education of the household head, and by off-farm income. Key words: Adoption, improved cassava, double-hurdle, Nigeria.

English

Five International Institute of Tropical Agriculture (IITA) drought tolerant and open pollinated varieties (OPVs) (lines) and four local varieties with various level of susceptibility to drought (testers) were used. These maize varieties were crossed using a line x tester mating design during the 2007 cropping season to determine the general combining ability (GCA) and specific combining ability (SCA); also the level of heterosis was investigated. Parental lines and hybrids were evaluated in Biu in 2008 and 2009 cropping seasons. Results from the analysis of variance and combining ability shows that there was high and significant level (P&lt; 0.05) of genetic variability among the parental lines used and their hybrids in days to tasseling, days to silking, anthesis silking interval (ASI), plant height, ear height, weight of cobs, dehusked cobs and grain yield, thus suggesting the possibility for genetic improvement. The study established that, there were significant (P&lt;0.05) differences of GCA effects of parents and that of SCA effects of hybrids. Estimates of GCA were consistently lower than SCA effects in almost all the traits evaluated. This suggests that high performing hybrids such as EVDT-99WSTRQPMC0 x EX-DAMBOA WHITE, EVDT-99WSTRC0 x EX-DAMBOA YELLOW andTZE-COMP3DTC1 x EX-DAMBOA WHITE may be used to develop potential varieties. The parents: EVDT-99WSTRC0, EVDT-99WSTRQPMC0, TZE-COMP3DTC1 and EX-BIU WHITE were identified as the best general combiners in terms of GCA for days to tasseling, days to silking, ASI, plant height, ear height, dehusked cobs and grain yield. &nbsp; Key words: Maize, combining ability, additive, non-additive genetic effects, drought tolerance.

Identification of Pro-vitamin A Cassava (Manihot esculenta Crantz) Varieties for Adaptation and Adoption through Participatory Research

In spite of diligent efforts by National Root Crops Research Institute (NRCRI) Umudike and International Institute of Tropical Agriculture (IITA) to make Nigeria the largest producer of cassava in the world, the adoption rate of elite cultivars by farmers is about 40% and that is unacceptable. In addition, all cassava cultivars presently grown in Nigeria are low in essential minerals, vitamins, and protein content, and high in cyanogenic content. Cassava with yellow roots contains elevated levels of β-carotene (pro-vitamin A), an essential nutrient, but they are not commonly grown in Nigeria. Because farmers select cultivars based on multiple criteria, participatory rural appraisal and selection are essential for a successful adoption of new improved varieties. A participatory rural appraisal (PRA) and sensory evaluation were conducted in Abia, Imo, and Ebonyi states of Nigeria to assess farmers’ preferences for pro-vitamin A cassava. Some of the farmer-preferred traits included high yield, early maturity, tolerance to pests and diseases, sweetness, high amount of dry matter (DM) content, easy peeling, marketable roots, and roots that keep long in the ground without decaying. High pro-vitamin A cassava cultivars TMS 01-1368, TMS 05-1636, and TMS 05-0473 were better than farmers’ cultivar NR 8082, because of their color, high premium price, nutritional value, texture, among others, and were selected for adoption.

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The genetic diversity of 40 African yam bean (AYB) accessions was assessed using amplified fragment length polymorphism (AFLP) markers. Seeds of 40 accessions of AYB obtained from the International Institute of Tropical Agriculture (IITA) and Institute of Agricultural Research and Training (IAR&amp;T) Ibadan, Nigeria, were grown in a greenhouse and young leaves from two weeks old plants collected for DNA extraction. The four primer combinations used generated a total of 1730 amplification fragments across the AYB accessions used in this study of which 1647 were polymorphic (95.20%). The number of amplified polymorphic AFLP bands per primer pair varied from 360 to 520 with an average percentage polymorphism of 95.6%. E-AGC/M-CAG produced the highest number of polymorphic bands (520). Polymorphic information content (PIC) values ranged from 0.9447 to 0.9626. The highest level of polymorphism (100%) was recorded for two primer combinations (E-AAC/M-CAG and E-ACT/M-CAG). The results of cluster analysis using UPGMA tree, grouped the 40 accessions of AYB into two major clusters with an overall similarity of 67.5%. The level of similarity between the accessions spanned 0.66 to 0.91. TSs 138 and TSs 139 were the most closely related accessions with high level of similarity index (0.91). Comparable results were obtained using Factorial Coordinate Analysis (FCO).&nbsp; The results from the present study confirm the robustness and the suitability of the AFLP as a molecular tool for the assessment of genetic diversity in AYB accessions. &nbsp; Key words: Amplified fragment length polymorphism (AFLP), cluster analysis, genetic diversity, Sphenostylis stenocarpa, polymorphism.

Genotype × environment interactions and yield stability of stress-tolerant open-pollinated maize varieties in the Eastern Cape province, South Africa

Genotype × environment interactions are inherent in multilocational trials and complicate identification of superior genotypes. The aim of the study was to determine yield performance and stability of 13 maize genotypes in five locations of the Eastern Cape province, South Africa. The genotypes assessed were: ZM305, ZM423, ZM501, ZM525, ZM621, ZM627 and Obatanpa from the International Maize and Wheat Improvement Centre; BR993 and COMP4 from the International Institute of Tropical Agriculture; four local checks, AFRIC 1, Okavango, Nelson's Choice, and PAN 6479. Yield data were subjected to analysis of variance (ANOVA) and additive main effects and multiplicative interaction (AMMI) analysis. According to ANOVA, genotype × environment interaction was significant. PAN 6479 (5.21 t ha-1) and ZM525 (5.19 t ha-1) were the highest-yielding varieties, whereas Okavango (4.08 t ha-1) showed the lowest yield. Based on AMMI analysis, BR993 and Obatanpa were the least stable genotypes. PAN 6479 and ZM525 showed specific adaptations to high potential environments. Obatanpa was adapted to environments with low-yielding potential, since improvement of the environment did not improve its yield. ZM501 was the most stable genotype, and showed no significant yield difference to PAN 6479. ZM501 can therefore be assigned to several environments in the Eastern Cape.

English

Cassava is ideal for biofortification due to its popularity as a root staple among populations with high vitamin A malnutrition. The crop is vegetatively propagated and retains the enhanced trait across generations. The combining ability for beta-carotene content and important yield trait was evaluated in a cassava F1 generation. Ten high beta-carotene clones from International Institute of Tropical Agriculture (IITA) were hybridized with ten local clones in a North Carolina Design II mating design. The F1 population was evaluated at the Kenya Agricultural Research Institute (KARI). A total of 125 families were evaluated, including 35 reciprocal crosses. The IITA parents had highly significant (P ≤ 0.001) General Combining Ability (GCA) for pulp colour and plant height. The GCA of the local parents was significant (P≤ 0.05) for harvest index, number of lobes (P≤ 0.05) and for plant height (P≤ 0.001). The Specific Combining Ability (SCA) was significant for harvest index and plant height at P≤ 0.05 and P≤ 0.001 respectively. Root pulp colour was influenced by both additive and non-additive genetic effects. There were also maternal effects associated with the trait. Results indicated that local cassava varieties can be improved for beta-carotene content without a decline in agronomic performance.

Screening of some cowpea genotypes for photosensitivity

Experiments were conducted in 2008 at International Institute of Tropical Agriculture (IITA) Kano Station. The varieties were planted in March which coincided with the dry season and in July for the rainy season planting. Data were collected on number of days taken from sowing to flower bud initiation, first opened flower and first pod maturity. This was aimed at evaluating the effects of daylenths on phenology. The results revealed that daylength had significant effect on phenology in all the genotypes. Four genotypes including IT99K241-2, IT97K 568-19, IT99K 213-11-1, IT98K 131-2 and IT99K 216-48-1 were found to be photoperiod sensitive while four genotypes which include IT99K 1092-2, IT97K 454-3, IT97K 409-4 and IT93K 452-1 were observed to be photoperiod insensitive. Based on the results, the cowpea genotypes were characterized into early (IT98K 131-2, IT99K 1092-2, IT93K 452-1, IT97K 409-4 and IT97K 454-3), medium (IT97K 568-19, IT99K 216-48-1 and IT99K 213 – 11 – 11), and late (IT99K 241-2) maturing varieties. Keywords : Cowpea genotype, Phenology, Daylength, Photosensitivity