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- ItemOpen AccessArtificial 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.
- ItemOpen AccessThe 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.
- ItemOpen AccessEffects 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.
- ItemOpen AccessEstimating 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.
- ItemOpen AccessInterrelationships 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.
- ItemOpen AccessA 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.
- ItemOpen AccessPartitioning 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.
- ItemOpen AccessPredicted responses to recurrent selection in maize (Zea mays L.)(Faculty of Agriculture, University of Ife, 1979) Fakorede, M. A. B.; Obilana, A. TundePrevious 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.
- ItemOpen AccessA 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.
- ItemOpen AccessSeasonal 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.
- ItemOpen AccessVariability 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.