Department of Plant Science

Permanent URI for this community

https://ir.oauife.edu.ng/handle/123456789/232

Department of Plant Science

Browse

Now showing 1 - 20 of 33

Open Access
A Role for the University of Ife in Increasing Agricultural Production
(Obafemi Awolowo University Press, 1974-04-30) Duncan, E. R.
My purpose in presenting this paper is to voice concerns about the production of food in relation to existing and expected needs, about present population trends, and to suggest that the University of Ife can play a significant role in this drama. My qualifications to discuss this segment of agricultural and economic development may not qualify me as an authority in Nigeria, but hopefully may justify an expression of my concern
Open Access
Insects and Human Welfare with Special Reference to their Role in Agricultural Production
(Obafemi Awolowo University Press, 1978-10-19) Adenuga, A. O.
This I believe is the second ineugural Lecture to be delivered by a Professor of Plant Science in this University but the first by a Nigerian Professor of Plant Science. My predecessor, Professor Duncan, who first inaugurated the chair of Plant Science showed in his treatise quite clearly the importance of weather in agricultural production in a discipline known as agro climatology. My own lecture today on "Insects and Human Welfare," is in the area of insect science known technically as entomology. You can see, therefore, that Plant Science has a broad scope, some of its disciplines seemingly unrelated to an uninitiated observer. Indeed, I have often been asked: 'If you study insects, which are in any case animals, why are you not in the Department of Animal Science?'. As an agricultural entomologist the ultimate aim of my study of insects is to be able to reduce the damages insect pests do to crop plants, livestock and agricultural produce, and quite recently, that function has been extended to the improvement of environmental factors under which beneficial insects like parasites or predators of insect pests and insects that pollinate flowers can multiply and thrive well. But principally because insect pests of crops are several times more numerous than pests of livestock, entomologists are based in the Department of Plant Science rather than the Department of Animal Science.
Open Access
Effects of crop spacing on weed competition and seed yield in cowpea, Vigna unguiculata [L.] Walp c.v. Ife Brown
(Faculty of Agriculture, University of Ife, 1979) Fadayomi, O.
When cowpea (Vigna unguiculnta [L.] Walp c.v. "Ife Brown") was planted at spacings of 50cm x 25cm and 50cm x 50cm. 31 and 15 percent yield increases were obtained over that of the conventional (100cm x 30cm spacing respectively Optimum yield was obtained under the 50cm x 25cm spacing with 4 weeks of weed-free maintenance, whereas 6 weeks of weed-free maintenance were required for the same under the 50cm x 50cm and 100cm x 30cm spacings. When weeds were allowed to compete with the crop for more than 4 weeks, yields decreased under the 50cm x 50cm and 100cm x 30cm spacings but yield reductions were not observed under the 50cm x 25cm spacing even with up to 6 weeks of weed competition.
Open Access
Predicted responses to recurrent selection in maize (Zea mays L.)
(Faculty of Agriculture, University of Ife, 1979) Fakorede, M. A. B.; Obilana, A. Tunde
Previous studies with computer simulation models have shown that standardised correlated response in one trait, y, to selection for another trait, x, should be the same in one generation regardless of whether selection is for x or for y. In the study reported herein, we tested the hypothesis that direct response to selection for trait x should be the same as standardised correlated response in trait x when selection is based on trait y. Additionally, we compared, observed and predicted correlated responses to seven cycles of reciprocal recurrent selection for grain yield in two maize populations Results obtained indicated that predictions of direct and standardised correlated responses showed poor agreement. Direct response to mass selection, however, agreed more closely with standardised correlated responses than did half-sib selection and S1 testing, whereas direct response to S1 testing agreed more closely with conventional correlated response than did the other two selection methods. Also, observed and predicted correlated response to reciprocal recurrent selection for grain yield showed poor agreement. However, predictions based on parameters obtained in the fourth cycle of selection agreed more closely with observed changes than similar estimates obtained from the original populations. Implications of these results in determining indirect selection criteria are discussed.
Open Access
Seasonal Variation in the Incidence of Yeast Rotters of Tomato Fruit in Soil and on various Parts of Tomato
(Faculty of Agriculture, University of Ife, 1979) Onesirosan, P. T.
Geotrichum candidum and Pichla Kluyveri, the two important yeasts which incite rots of tomato fruits in southern Nigerian were frequently isolated from field/soil and various parts of the host plant during the wet season but rarely during the dry season. However, the frequency of their isolation remained uniformly high in forest soil in both seasons. G. candidum was isolated from the shoots and roots of seedlings as well as the flowers and fruits; it was also a frequent contaminant of tomato seeds extracted during the wet season. P. Kluyvery on the other hand, was more prevalent on the stems and leaves of mature plants.
Open Access
Artificial Defoliaton of Cowpea [Vigna unguiculata (L.) Walp.] cv. Ife Brown to Simulate Insect Damage: Effects on Crop Performance
(Faculty of Agriculture, University of Ife, 1980) Akingbohungbe, A. E.
The effects of defoliation on cowpea, Vigna unguiculata (L.) Walp cv. Ife Brown, were studied in the screenhouse by removing varying proportions of the laminae of leaflet along-the transverse plane, to give varying nominal levels of defoliation. Plants subjected once to 25%, SO%, 75% and 100% defoliation at either the primary leaf stage, the first trifoliate leaf stage or the second trifoliate leaf stage, were not adversely affected with respect to days to peak flowering, number of flowers per plant, number of pods per plant as well as number and weight of seeds per plant. However, 100% defoliation significantly delayed the days to first flower production. When plants were subjected to 25%, 50% and 75% nominal defoliation once a week for a period of three weeks, commencing at the first trifoliate leaf stage, significant treatment effects were observed with the 75% defoliation adversely affecting the number of pods per plant, number and weight of seeds per plant. I t was also observed that defoliated leaflets tended to compensate by increasing their widths. The importance of the results are discussed in relation to the impact of defoliators and recommendation's for their control in cowpea production.
Open Access
The effect of Slaughter Weight on Organ and By-product Weights of Pigs
(Faculty of Agriculture, University of Ife, 1981) Sonaiya, E. B.
The effect of slaughter weight on organ and by-product weights in pigs was determined by slaughtering 101 pigs at six slaughter weights ranging from 22 to 97kg. Slaughter weight had a highly significant influence on the weight of all organs and by-products such as liver, spleen, kidney, heart, hair, skin, head, blood, bone and kidney fat. Heavier slaughter weights above 74kg appear more advantageous in terms of the amount of by-products obtained but also .produced excessively fat carcasses. Breed and sex had no significant effect on organ and by-product weights. The proportion of organs declined while non-organ by-products increased with increasing body weight. The utilisation of abattoir by-products for food, feed and as industrial raw materials has the potential to increase the profitability of pig production.
Open Access
Estimating Kernel Weight in Maize
(Faculty of Agriculture, University of Ife, 1981) Fakorede, M. A. B.; Orisadare, S. S.
In an experiment involving 20 maize (Zea mays L.) cultivars and five sample sizes (100,500,750 and 1000 kernels) replicated four times, it was found that sample weight increased linearly (r2 = 0.81) as sample size increased. This suggests that mean weight/kernel did not differ significantly among sample sizes. In similar trials involving 21 S1 lines developed from two maize cultivars (FARZ 23 and FARZ 27) but utilising sample sizes of 25, 50, 75, 100 and 125, mean weight/kernel showed a curvilinear response to increased sample size with the point of inflection at approximately the sample size of 100 kernels. This suggests that mean weight/kernel was variable for sample sizes less than 100 kernels. It seems, therefore, that kernel weight in maize can be estimated from small sample sizes (e.g. 100 and 125) kernels in order to save time and expenses when evaluating a large number of lines in a breeding programme.
Open Access
Variability in Reaction of Ife Brown (Irawo) to the Cowpea Aphid-borne Mosaic Virus
(Faculty of Agriculture, University of Ife, 1982) Fatunla, T.; Ladipo, J. L.
Cowpea (Vigna unpiculata ssp. unguiculata) (L.) Walp. cv. Ife Brown showed genetic variability for resistance to cowpea aphid-borne mosaic virus. It was shown that Alabunch and Westbred, two Ife Brown parents, carry resistance genes to the virus in their populations. Two generations of individual plant selection in Ife Brown resulted in the production of four true breeding lines resistant to the cowpea aphid-borne mosaic virus.
Open Access
A Note on the Heritability of Pod Length and Number of Seeds per Pod in Cowpea, Vigna unguiculata s.sp. unguicalata (L) Walp
(Faculty of Agriculture, University of Ife, 1982) Ogunbodede, B. A.; Fatunla, T.
KR 91, (a short podded cowpea cultivar) was crossed to Paraquay No. 2, (a long podded cultivar), while Victor (a crowder) was crossed with B33 (a non-crowder) to study the inheritance of pod length and seed number respectively in the two crosses. The two parents, PI, P2, and the progenies F1, BC1, BC2 and F2 of each cross were evaluated at the University of Ife Teaching and Research Farm. Narrow sense heritability estimates of 72.1% and 36.8% were obtained for pod length and number of seeds per pod respectively. About seven and eight pairs of genes control pod length and number of seeds per pod respectively.
Open Access
Interrelationships between Pratylenchus brachyurus and Helicotylenchus pseudorobustus in Sugarcane
(Faculty of Agriculture, University of Ife, 1982) Onapitan, J. A.; Amosu, J. O.
Greenhouse studies showed that Pratylenchus brachyurus and Helicotylenchus pseudorobustus singly and in all combinations tested, did not significantly suppress both top growth and root development of sugarcane. Data on mean population increase, showed that P. brachyurus multiplied faster than H. pseudorobustus singly and in all combinations, and had suppressive effect on the reproduction of H. pseudorobustus.
Open Access
A Proposed Procedure for Rapid Development of Inbred Lines for the Production of Hybrid Maize in Nigeria
(Faculty of Agriculture, University of Ife, 1982) Fakorede, M. A. B.
A procedure is described for the rapid development of inbred lines to be used as parents of high-yielding hybrid cultivars of maize (Zea mays L.). This procedure involves the production of S1 lines from three unrelated populations A, B, C whose Fl hybrids are known a priori to demonstrate significant yield heterosis. The S, lines are evaluated per se and S2 lines obtained from the best performing 5 or more S1 lines from a population are intercrossed with those-from the other populations to give 75 or more S2 x S2 crosses. The S2 x S2 crosses are evaluated with check cultivars (e.g. cultivar hybrids, the best widely grown cultivar and single-cross hybrids, if available) and the top 5 are selected for the National Zonal Maize Yield Trials (NZMYT) coordinated by the National Cereals Research Institute (NCRI), Ibadan. S4 x S4 hybrids of these top 5 selections are evaluated in the NZMYT as well as several other locations available to the researcher and inbred lines of the best 1 or 2 hybrids are released as parent materials. The advantages of this procedure include (i) simultaneous inbreeding and evaluation trials, (ii) flexibility for concurrent population improvement and extraction of inbredlines, and (iii) with two rainfed cropping seasons and an off-season with irrigation facilities, near-homozygous inbred lines (F 0.99) can be obtained within 3 calendar years.
Open Access
Partitioning of Dry Matter in Relation to Yield Performance in Five Cultivars of Cowpea, Vigna unguiculata s. sp. unguiculata
(Faculty of Agriculture, University of Ife, 1982) Alofe, C. O.; Amusan, A. A.
Dry matter accumulation (DMA) and its pattern of partitioning were studied in five cultivars of cowpea, Vigna unguiculata ssp. Unguiculata (L.) Walp. Generally, TVx 183P9G and TVx 1193-9F flowered and podded earliest while TVu 1190E and Tvu 1977 were the slowest to flower and pod; Ife Brown was intermediate. TVu 1977 and TVu 1190E accumulated more dry matter in their stems, leaves and pods than any of the other cultivars. The proportion of dry matter deployed into pods was highest in TVx 1836-9G (81 percent) and TVx 1193-9F (75 percent), and least in TVu 1190E and TVu 1977 (63 and 67 percent each). In Ife Brown, it was 67 percent. Grain yields were similar in TVu 1977, TVu 1190E and TVx 1836-9G (505, 528 and 516 kgha respectively), but only 3 59 kgha in Ife Brown. I t was 472 kgha in TVx 1193-9F. Harvest index was low in TVu 1190E and TVu 1977 (18 and 20 percent, respectively), medium in Ife Brown (23 percent) and high in TVx 1836-9G and TVx 1193-9F (30 and 26 percent respectively). Correlation between seed yield and DMA though positive, was not significant. No correlation was observed between seed yield and harvest index, but correlation between DMA and harvest index was negative and significant.
Open Access
Evaluation of Bacilus Thuringiensis Berliner and Baculovirus Heliothis as Microbial Control Agents of Heliothis Armigera (Hubner) and Spodoptera Littoralis (Boisduval) on Tomata.
(Obafemi Awolowo University, 1985) Lutwama, Julian Julius; Matanmi, B. A.
Field plantings of tomato grown during both the rainy and the dry seasons were subjected to foliar sprays of Bacillus thuringiensis Berliner (B.t.), Baculovirus heliothis (B.h.) and carbaryl, plus Tenac and Gustol adjuvants against larvae of Heliothis armigera (Hubner) and Spodoptera littoralis (Boisduval). In the laboratory, the dosage-mortality response of these larvae to B.t. and B.h., was also determined. This involved using the diet-surface treatment bioassay technique and obtaining the lethal concentrations (L.C.50) after probit analysis. H. armigera larvae were found to be highly susceptible to both B.t. and B.h. but S. littoralis larvae appeared highly susceptible to only B.t. The 0.5 Kg/ha and 1.0 Kg applications of B.t. gave good field control of the larvae, with the later giving control comparable to that of the 1.5 Kg/ha carbaryl application. B.t. and B.h. were shown to be compatible, though the combinations were not significantly more effective than either of the pathogens alone. Combinations of B.t. and B.h. with carbaryl were also not significantly different from either of the pathogens alone. The 0.5 Kg/ha application of B.t. with 0.5 Kg/ha carbaryl was as good as the 1.5 Kg/ha carbaryl application, thus indicating that B.t. could partially replace carbaryl in the spraying programme. The adjuvants GustolR and Tenac were compatible with B.t. and B.h. but they did not significantly increase the effectiveness of the pathogens.
Open Access
Studies on Cowpea Varietal Resistance to the Cowpea Flower and Pod Borer, Maruca Testulalis (Geyer) (Lepidoptera Pyralidae).
(Obafemi Awolowo University, 1985) Echendu, Thank-God Nnamdi; Akingbohungbe, A.E.
Several varieties of cowpea, Vigna unguiculata s.sp. unguiculata (L,) Walp., were screened for resistance to the cowpea flower and pod borer, Maruca testulalis (Geyer) using free-choice field trials, cohort tests in large screened cages and no-choice tests in the screenhouse and the laboratory. The damage potential of M. testulalis on Ife Brown cowpea was also studied using controlled infestations in order to establish a baseline infestation level that could be used to differentiate resistance effectively in no choice tests. The study on the damage potential showed that successful establishment of the first in star larvae could only be obtained and sustained throughout the crop growth at the flower bud stage. At this stage, infested plants showed significantly reduced numbers of flowers and pods as well as seed yield. Two first in star larvae per plant was the lowest infestation that produced such significant differences between infested plants and the control. Thus, it is suggested as an adequate level for differentiating susceptible and resistant varieties in no choice tests employing Ife Brown as a standard. The free choice field trials showed significant differences in the degree of susceptibility of the varieties screened. Using overall susceptibility indices that considered some parameters associated with pest attack and which could affect flowering, podding and seed yield, TVu 1896 A/G, Sese, EW/1 and H64-3 were found to be moderately resistant to flower damage; while 2Ak and TVu 1896 A/G were shown to be moderately resistant to pod and seed damage. The field resistance was confirmed by the cohort and no-choice tests. TVu 1896 A/G and H51-1 were found to be resistant to pod and seed damage while TVu 946 and 2Ak were moderately resistant. Non-preference for oviposition and larval feeding appeared responsible for the resistance observed. Antibiosis manifested in form of reduced weight and size, and lengthened pupal period was also observed.
Open Access
Genotype X Environment Component of Variance and its Implications in Maize (Zeamays L.) Yield Trials.
(Obafemi Awolowo University, 1985) Adisa, Aramide Omolara; Fakorede, M. A. B.
Grain yield data obtained from yield trials conducted in 1981 and 1982 for five open-pollinating cultivars and eight varietal hybrids of maize (Zea mays L.) were used to investigate the effectiveness of 3 different yield trial methods. These included experiments A: 2 years, 2 locations, 1 planting date; experiment B: 1 year, 2 locations, 3 planting dates, and experiment C: 2 years, 1 location, 3 planting dates. Variance components were obtained for each method and optimum combinations of numbers of years, locations, planting dates and replications for varietal testing were determined by calculating theoretical standard error of the mean (SEM). Analysis of variance for the three methods showed highly significant location, year, planting date and genotype effects. SEM of 0.256 was obtained for 2 years, 2 locations, 1 planting date and 4 replications, and this was used as the standard for comparing the other two methods. When planting dates were substituted for years in experiment B, the SEM of 0.256 was obtained for combinations ranging from 1 year, 8 locations, 2 planting dates and 1 replication, to 1 year, 2 locations, 2 planting dates, and 4 replications. Substituting planting dates for location in experiment C however, resulted in the use of a larger number of planting dates than in experiment B, and not less than a 1-year period of testing to obtain the minimum SEM of 0.256. Planting dates can therefore be effectively substituted for years in order to reduce the time for conducting preliminary maize yield trials. Planting dates can also be substituted for locations where funds but not time, are limiting.
Open Access
Six-Legged Science in Nigeria and its Development
(Obafemi Awolowo University Press, 1985-03-12) Akingbohungbe, A.E
"Six-legged science" is a literal substitute for the more technical term, "entomology" which, put simply, is the study of insects. Insects are characterised by a number of features among which is the possession of six legs (a pair each per thoracic segment) and hence the substitute term, "six-legged science". Traditionally, entomology had as its dimensions the following areas of specialization: insect morphology, insect taxonomy, insect physiology, insect ecology, medical and veterinary entomology, and agricultural entomology. The last two are also frequently integrated variously to give what is called, "economic entomology." The hall-mark of today's science is the high degree of specialization evolved, and entomology has not been an exception.
Open Access
Inheritance of Yield and Agronomic Traits in a Maize (Zeamays L.) Population at Two Levels of Inbreeding.
(Obafemi Awolowo University, 1986) Ajala, Samson Oyewole; Fakorede, M. A. B.
Hybrids resulting from diallel crosses of ten radom lines at the second (S2) and fifth (S5) generations of inbreeding in the TZSR-W population of maize (Zea mays L.) were studied. Eight of the lines were common to both generations. At both generations, general combining ability (gca) was more important than specific combining ability (sca) for most traits. For grain yield however, gca and sca were nearly equal. Therefore, recurrent selection methods that utilize both additive and non-additive gene actions should be used to improve the population. Generally, lines with positive gca effects at the S2 generation also had positive gca at the S5 generation with line 013 being the best at both generations. However, the relative performance of crosses (sca) differed between the two generations. Appreciable inbreeding depression had occurred at the S2 generation with little further depression at the S5 generation. The preponderance and relative stability of gca effects, and the magnitude of inbreeding depression at the S2 generation suggest that good inbred lines can be selected as from the S2 generation. However, the inconsistent ranking of hybrids for sca effects at both generations implies that the yielding ability of such selected lines must be specifically tested to identify the best hybrid combinations. Correlation, stepwise multiple regression and path-coefficient analyses indicated that vigorous lines that mature early, with long rather than wide ears will be high-yielding in hybrid combinations. These analyses also showed that shelling percentage, emergence percentage and numbers of days to silking of S2 X S2 hybrids positively influenced grain yield in the S5 X S5 hybrids. Therefore, these traits could be used as indirect selection criteria for high-yielding hybrids.
Open Access
Genetic and Environmental Analysis of Vegetative and Yield Traits in the Oil Palm ( Elaeis Sp.).
(Obafemi Awolowo University, 1986) Opeke, Bolanle olufunmilayo; Fakorede, M. A. B
A total of 21 hybrids of oil palm consisting of four Elaeis,guineensis palms selected for shortness, three F1 interspecific hybrids (Elaeis oleifera x E. guineensis), 13 hybrids from the first backcross gene-ration (BC1) of the F1 interspecific hybrid crossed to E. guineensis and a standard cross used as check, were evaluated for yield and vegetative traits with a view to determining a suitable breeding method for short-stemmed palms. Associations among all traits were also investigated. Furthermore, the effects of climatic factors on vegetative and yield traits were investigated using correlations, stepwise multiple regression and path coefficient analyses. In addition, two environmental indices (biological and biophysical) were compared for yield stability using nine Dura (D) x Tenera (T) hybrids. Data for evaluation were collected from three field plantings made at the Nigerian Institute for Oil Palm Research near Benin City, between 1960 and 1969; and data collected covered the period 1963 to 1982.Generally, the backcross hybrids were superior in cumulative' trunk height and annual trunk increment compared to E. guineensis palms selected for shortness, the F1 interspecific hybrids and the check. However, average yield (as measured by fresh fruit bunch yield) of the backcross hybrids was 22.8-48.2% lower than the mean of the F1 interspecific hybrids. Number of bunches and mean bunch weight were associated with vigor characteristics (trunk height, crown diameter and number of leaves) in the backcross hybrids. Total sunshine hours and minimum relative humidity at about 18-21 months before harvest demonstrated the strongest associations with number of bunches and fresh fruit bunch yield. Generally, progenies maintained their relative ranking for environmental response regardless of the index used to quantify the environment.
Open Access
Genetic Variability and Predicted Responses to Four Types of Progeny Selection in a Nigeria Maize (Zeamays L.) population.
(Obafemi Awolowo University, 1986) Adeyemo, Moses Olusegun; Fakorede, M. A. B.
Genetic variability and predicted responses to full-sib (FS), half-sib (HS), Si and S1 testcross (TCH) selection methods were studied in the open-pollinating maize variety, TZSR-Y-1. Evaluation of progress after one cycle of selection was also done. Grain yield and seven agronomic traits were investigated. Mean grain yield ranged from 3.4 to 9.2 t/ha for FS, 2.9 to 7.5 t/ha for HS, 1.75 to 8.0 t/ha for S1 and 3.2 to 8.8 t/ha for TCH. Genetic variances ( 4;2) were largest for S1 families but there were no consistent trends for c2 among the other progeny types. Additive genetic variance constituted- the major portion of the total genetic variance for grain yield and the agronomic traits. Heritability estimates were moderate to high for nearly all agronomic traits of the four progeny types. Generally, only the correlations of yield with ear number per plot and ear length had coefficients appreciably larger than 0.50; these two traits were therefore the primary determinants of grain yield. Largest predicted direct gain per season of selection for grain yield was obtained for S1 families followed by TCH and FS which differed little. HS selection gave the smallest predicted gain. Predicted correlated responses in grain yield assuming selection was done for agronomic traits were generally smaller than predicted direct responses to selection for grain yield. After one cycle of selection, yield improvements of the derived populations relative to the source population were -2.5% for SI, 8.8% for HS, 13.5% for FS, and 14.6% for TCH selection methods. On the basis of operational efficiency and predicted versus realized gains from selection, FS family selection would be more effective than the other selection methods studied for improving the maize variety TZSR-Y-1.