| A comparison between hydroponics systems and pots for growing wheat in the greenhouse | Labuschagne, M. T. | 2007 |
Keywordsemergence, hydroponics, wheat, yield AbstractGrowing wheat hydroponically for crossing block and germplasm multiplication purposes may hold emergence, yield and seed quality advantages compared to traditional planting methods. The aim of this study was to compare wheat planted in pots with soil to hydroponically grown wheat in terms of emergence and yield and yield components. Two wheat cultivars, Baviaans and Steenbras, were evaluated in two identical hydroponic systems using two different nutritional solutions, and in pots with soil. The two hydroponic systems provided a better emergence environment compared to the potting solution. For both Baviaans and Steenbras, in the chemicult solution, higher values for measurements were observed than in their pot solution-planted counterparts. For all yield related characteristics, the hydroponic cultivation methods yielded superior results to the potting cultivation method. The chemicult solution resulted in higher yields than the Bugbee solution. It can be concluded that wheat can be grown more effectively in a hydroponics system in the greenhouse than in pots with soil, using a chemicult rather than the Bugbee solution. AuthorsLabuschagne, M. T. and du Toit, A.
G.A. Year Published2007 PublicationSouth African Journal of Plant and Soil LocationsDOI10.1080/02571862.2007.10634792 This article contributed by:
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| A comparison between the linear regression and AMMI approaches to study multi-site trials using a sample of South African maize trials | Falkenhagen, E. | 1996 |
KeywordsCultivars, scale of selection, Zea mays L. AbstractGrain yield for 21 maize cultivars common to 10 localities and three harvesting seasons was used to compare the Finlay-Wilkinson and the additive main effects and multiplicative interaction (AMMI) methods of studying interactions in multi-site trials. Both methods showed variability and unpredictability with respect to year-to-year results. Each method considered the data from different points of view, bringing to light various aspects of the variability contained in the data. The cultivars were loosely ordinated by the AMMI method along a gradient representing length of growing season in two years out of three and also when the years were analysed jointly. In order to maximize the predictive ability of the AMMI method, selection should be made using the AMMI 0 scale of treatment estimators because of its minimal sampling variance. AuthorsFalkenhagen, E., Funnah, S. M. and du Toit, W. Year Published1996 PublicationSouth African Journal of Plant and Soil Locations- Bethlehem, South Africa (-28.2333, 28.3)
- Ermelo, South Africa (-26.518, 29.984)
- Litchenburg, South Africa (-26.1473, 26.1597)
- Molopo, South Africa (-26.9207, 20.678)
- Ottosdal, South Africa (-26.8114, 26.0028)
- Potchefstroom, South Africa (-26.7145, 27.097)
- Potgietersrus, South Africa (-24.1839, 29.0128)
- Schweizer Renecke, South Africa (-27.1833, 25.3333)
- tweebuffels, South Africa (-28.3866, 27.8802)
- Viljoenskroon, South Africa (-27.2122, 26.9555)
DOI10.1080/02571862.1996.10634384 This article contributed by:
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| A comparison beween short-term chemical and biological methods to measure phosphorus availability in sludge-amended sesquioxic soils | McLaughlin, M. J. | 1988 |
KeywordsPhosphorus availability, sesquioxic, sewage sludge, soil amendment, soils AbstractDue to the transformations which sludge undergoes after addition to soil, single measurements of P availability are of little value in soils which have recently received additions of sewage sludge. This study assessed six procedures on two soils—a clay of the Griffin form (Typic Haplorthox) and a sandy clay loam of the Clovelly form (Tropeptic Haplorthox). Five chemical tests based on laboratory incubation and chemical analyses were compared to a short-term bioassay procedure. Soil—sludge and soil—inorganic P mixtures (supplying 375, 751 and 1503 mg P kg−1 soil) were incubated in the laboratory for up to 92 days, and available P assessed by extraction with Bray 1, Bray 2, Olsen, ISFEI and CaCl2 solutions. The bioassay was based on the short-term uptake of P by P-deficient Italian ryegrass (Lolium multiflorum var. Midmar) from soil—sludge or soil—inorganic P mixtures. Ryegrass cumulative P uptake and amounts of plant-available P extracted by the various reagents was regressed against amount of P applied for each soil x P—source x time combination. The ratio of the slopes of the (linear) regression lines for the two P sources was then used as a measure of the relative efficiency (E value) of sludge as a P fertilizer compared with inorganic P source. All the chemical tests greatly underestimated the effectiveness of sludge P as a source of fertilizer P. %E values derived by laboratory incubation and chemical extraction were approximately 50–70% initially for Bray, Olsen and ISFEI methods, and tended to remain constant or decrease with time. %E values from incubation and extraction with CaCl2 were generally less than 10%. In contrast initial %E values from the bioassay were 44 and 64% for the Clovelly and Griffin soils respectively, and these values increased to 82 and 118% after 97 days of root—P source contact. Thus laboratory incubations of soil—sludge mixtures and extraction of various P forms cannot be reliably used as an indication of the P fertilizer value of the sludge. AuthorsMcLaughlin, M. J. Year Published1988 PublicationSouth African Journal of Plant and Soil LocationsDOI10.1080/02571862.1988.10634273 This article contributed by:
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| A comparison of culture methods for tobacco (Nicotiana tabacum) anthers | Steyn, Anita E. | 1997 |
KeywordsAnther culture, double layer medium, liquid medium, Nicotiana tabacum, solidified medium AbstractThree different anther culture methods for the South African tobacco cultivars C11 × WOSB and CDL 28 were tested. The yield of haploid plantlets produced using a solidified or double-layer medium was significantly higher than with the use of a liquid culture medium. The former two media showed no significant differences. Important considerations which must be taken into account when deciding on the optimum culture method for anther cultures are also discussed. AuthorsSteyn, Anita E., Brink, J. A. and Coetzer, L. A. Year Published1997 PublicationSouth African Journal of Plant and Soil LocationsDOI10.1080/02571862.1997.10635076 This article contributed by:
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| A comparison of head infection and blight development caused by Fusarium graminearum and Fusarium crookwellense in wheat | Boshoff, W.
H.P. | 1999 |
KeywordsFusarium crookwellense, Fusarium graminearum, head blight, wheat AbstractThe objectives of this study were to compare the infection of wheat heads by Fusarium graminearum and F. crookwellense and to determine the effect of temperature on head blight development induced by these species. Scanning electron microscopy of spikes of the wheat cv. Palmiet revealed no differences in the infection process between F. graminearum and F. crookwellense. In glasshouse experiments, F. graminearumwas more pathogenic than F. crookwellense at constant ± 22°C and ± 24.6°C, whereas F. crookwellense was more pathogenic at ± 13.8X. Both species caused more severe head blight at 22°C and 24.6°C than at 13.8°C. AuthorsBoshoff, W.
H.P., Pretorius, Z. A. and Swart, W. J. Year Published1999 PublicationSouth African Journal of Plant and Soil LocationsDOI10.1080/02571862.1999.10634851 This article contributed by:
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| A comparison of HMW-GS, LMW-GS and RAPD fingerprinting for cultivar identification of some South African wheat cultivars | Labuschagne, M. T. | 1998 |
KeywordsHMW-GS, fingerprinting, LMW-GS, RAPD, wheat AbstractAccurate identification of breeding material is very important for the plant breeder. In South Africa, high molecular weight glutenin subunits (HMW-GS) have so far been used for wheat cultivar identification. This method can often not distinguish between cultivars, and other techniques need to be investigated. The aim of this study was to compare HMW-GS, low molecular weight glutenin subunits (LMW-GS) and random amplified polymorphic DNA (RAPDs) for wheat cultivar identification. Five commercial wheat cultivars were analysed using the above three methods. The HMW-GS failed to distinguish between the five cultivars. LMW-GS could clearly distinguish between the cultivars, but banding pattern interpretation was more complicated than for HMW-GS. RAPDs could distinguish between the five cultivars with three different primers, but were expensive and would need an increased number of primers with an increase in cultivars. We concluded that HMW-GS should be used for initial cultivar identification, as it is simple and reliable. Where they fail to distinguish between cultivars, the LMW-GS should be used for final identification. AuthorsLabuschagne, M. T., Maartens, H. and Oberholster, A. M. Year Published1998 PublicationSouth African Journal of Plant and Soil LocationsDOI10.1080/02571862.1998.10635133 This article contributed by:
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| A comparison of methods used for the extraction of K in soils of the Western Cape | Thompson, G. R. | 1995 |
KeywordsExchangeable K, potassium, soil extractants AbstractA number of common soil extractants, mainly those used for soil P, were used to extract K from a range of widely differing soils which occur in the Western Cape; the objective being to evaluate the simultaneous determination of P and K availability. Soil samples were taken mainly from the upper horizons of 110 profiles representing the dominant soil forms occurring in this region. The soils varied from highly weathered, deep, well-drained acid Oxisols (Hutton form) to younger less developed duplex Alfisols (Swartland, Glenrosa and Kroonstad forms) and deep sandy Inceptisols (Fernwood form). The soils exhibited a wide range of values of clay content, CEC, pH and exchangeable K. Seven soil P extraction methods (Bray No. 1, Bray No. 2, citric acid 1%, Olsen, ISFEI (Na), Ambic and Mehlich No. 3) were compared with two K extraction methods, (0.5M NH4CI and M NH4OAc). All the methods gave K indices which were significantly correlated with one another (r> 0.9). The extractants containing NH/were better correlated with one another than with the other extractants. Significant linear relationships were obtained with all the methods between extractable K and soil K-values determined using the NH4OAc method over a range of values from < 10 mg kg−1 to over 300 mg kg−1. Apart from the results of the Bray No. 1 and ISFEI methods, which exhibited lower extractability, all R2 values were greater than 0.9. It appears that any of the methods used for extracting soil P are suitable for assessing the K status of the soils of this region. AuthorsThompson, G. R. Year Published1995 PublicationSouth African Journal of Plant and Soil LocationsDOI10.1080/02571862.1995.10634329 This article contributed by:
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| A comparison of seed vigour tests for maize (Zea mays L.) | van de Venter, H. A. | 1991 |
KeywordsCorn, emergence, low temperature germination test, maize, seed vigour, Zea mays AbstractA number of seed vigour tests were conducted on two groups of maize seed lots. One group consisted of six seed lots of different cultivars while the other group consisted of six sub-lots of one cultivar, artificially aged for different periods. Seed vigour tests included in the study were, a low temperature germination test (incubation in rolled paper towels at 13°C), the soil cold test, the accelerated ageing test and an osmotic stress test. The results of the vigour tests were correlated with the emergence of the seed lots in four field trials representing different sets of environmental conditions. The low temperature germination test was found to have the greatest overall predictive value for field emergence. The advantages and disadvantages of the low temperature germination test compared with the soil cold test, which has gained wide acceptance as a standard seed vigour test for maize, are discussed. Authorsvan de Venter, H. A. and Lock, H. W. Year Published1991 PublicationSouth African Journal of Plant and Soil LocationsDOI10.1080/02571862.1991.10634570 This article contributed by:
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| A comparison of several nitrogen- availability indices on four Natal maize-producing soils | Schroeder, B. L. | 1985 |
KeywordsLeaf-N content, maize, nitrogen application, nitrogen indices AbstractFour methods used in obtaining nitrogen-availability indices were compared using soil and plant samples taken from maize trials conducted on four widely differing Natal soils. NO3 − N was determined after extraction of the soil with NH4HCO3, Ca(OH)2 and KCl, using a specific ion electrode, phenoldisulphonic acid and brucine respectively. In addition, NO3 -N and NH4 + -N were determined after steam distillation of KCl extracts. The measurements so obtained were correlated with the rates of nitrogen application and leaf-N content at flowering. The four NO3 − -N determinations were all closely correlated with each other and with the level of N applied. The overall correlation across soils between N applied and increase in NO3 − -N exceeded 0,85. Inclusion of NH4 + - N did not materially improve the relationship between soil test and N application rate. NO3 − -N was also well correlated with leaf-N content. The levels of NO3 − -N measured in the absence of fertilizer N relate well to previously measured N responses on these soils. AuthorsSchroeder, B. L., Farina, M.
P.W. and Fey, M. V. Year Published1985 PublicationSouth African Journal of Plant and Soil LocationsDOI10.1080/02571862.1985.10634160 This article contributed by:
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| A comparison of the herbage and seed yields of annual cool season pasture legumes in the Bathurst, Alexandria and Humansdorp areas | le Roux, C.
J.G. | 1991 |
KeywordsGrowth curves, Ornithropus spp., Trifolium vesiculosum, Vicia spp. AbstractThe herbage and seed yields of annual cool season pasture legumes at three coastal sites in the eastern Cape are compared. Fair yields were obtained at the high rainfall sites, but at the low rainfall site the crops were unreliable. The highest yields were obtained from Trifolium vesiculosum, Vicia spp. and Ornithropus spp. Monthly production figures for the more promising legumes are provided. Authorsle Roux, C.
J.G., Daines, T., Ingpen, R. A., Oosthuysen, E. and Swart, J. S. Year Published1991 PublicationSouth African Journal of Plant and Soil LocationsDOI10.1080/02571862.1991.10634580 This article contributed by:
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