Summary: The future mass propagation of elite families of Pinus patula by cuttings is a realistic method of deployment if the short-term performance of cuttings and seedlings are confirmed at harvesting. This will impact significantly on the future outlook of forestry in South Africa as softwood yields are improved substantially through the introduction of material of high genetic value in commercial plantings. This, however, will require significant changes in future silviculture and other management practices as foresters and plantation staff learn to regenerate, maintain, and schedule the harvesting of cutting stands according to a different set of demands as a result of the change in plant type. Contrary to operational experience, cutting survival was similar to seedling survival in all field studies. This indicates that factors other than those that were studied and reported on, such as planting techniques, may be contributing to mortality. Also, due to the different root structure of cuttings they may be more fragile. The similar survival observed in these trials, therefore, may have been due to the close supervision given to the planting operations by the research staff. Although survival was similar, both plant types survived unacceptably poorly in the majority of studies with an average stocking of approximately 50% at one year. It is therefore anticipated that commercial stands will require several blanking operations in order to achieve an acceptable stocking in excess of 85% by the following planting season. The reduction in expected profitability as a result of blanking costs, delayed establishment, and the loss of improved genetic plant material, indicates that this is an area that still requires further research irrespective of what plant type is being planted. The pathogen, Fusarium circinatum, was commonly isolated from the planting stock before and after planting in two studies. Due to its virulent nature, it was assumed that mortality on the trees on which F. circinatum was isolated was principally due to this pathogen. At planting all plants were observed to be healthy and free of disease indicating that this pathogen maybe carried from the nursery to the field in a cryptic form, either inside or outside the plant tissue , which results in the death of the newly planted tree. In two field studies, where F. circinatum was commonly isolated, the application of Benomyl fungicide and to some extent the biological control agent Trichoderma harzianum at planting appeared to improve survival although this improvement was not significant. Laboratory studies, designed to determine alternatives to Benomyl fungicide, indicated that three fungicides (Octave, Folicur and Tilt), three sterilants (Sporekill®, Prasin®and Citex®) , as well as a biological control agent (T.harzianum), were all highly successful in controlling F. circinatum colony growth in vitro. It is recommended that these products undergo nursery testing , where the plant material is inoculated with F. circinatum spores, in order to test their efficacy and possible phytotoxicity in vivo before commercial application. Post-planting survival was also affected by site climate . Greater temperature extremes, as well as lower humidity and less rainfall resulted in poor survival. Plant dimension at planting was found to interact with site quality where it was a significant factor on a poor quality site. Optimal cutting dimensions at planting was a root collar diameter of 2.8 - 3.2 mm, and a stem height greater than 7 cm at planting for cuttings produced in cavities 90 ml in volume. Optimal seedling dimensions at planting were a root collar diameter of 1.8 - 2 mm, and a stem height of 10 - 15 cm for seedlings produced in cavities 80 ml in volume. In a separate study, plant morphological criteria influenced medium-term growth, where greater root mass and thicker cutting root collar diameters at planting improved field growth performance for seven years after planting. A greater root mass at planting was achieved by raising cuttings in containers that could support greater medium volume. From the study it was concluded that cuttings should be raised for an approximate period of 9 months in container cavities no smaller than 80 ml in volume and possess an oven-dry root mass of 0.3 - 0.5 g at planting. In addition to similar survival, the cuttings in this study grew either similarly to, or in some cases out-performed, the seedlings that were used as a control. Several other published studies indicate that hedge maturation poses the greatest threat to the success of softwood cutting deployment. This is especially true in clonal forestry and methods to maintain juvenility, such as cold storage of shoots and cryopreservation, require further research before clonal plantations of P. patula can be realised. In the studies carried out on family hedges in this report, the effect of donor hedge maturation was found to influence nursery management practice and the characteristics of rooted cuttings. The nursery data indicates that rooting efficiency, root system quality, and stem size and form, all decline with increasing hedge age particularly from two years after the date of sowing. A decline in root system quality was particularly apparent and was observed prior to a decline in rooting efficiency. If field trials indicate poorer performance from older hedges , it may be necessary to determine whether the causes are purely ontogenetic, morphological, or both before drawing final conclusions about hedge longevity. Until such results are known, it is recommended that P. patula cuttings should be propagated from seedling donors maintained as hedges , approximately 15 cm high, for a period not more than three years from the date of sowing. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

As restoration ecology has matured as a science there has been increased interest in the relationship between species diversity and landscape health. Degraded landscapes tend to be resource poor, which limits species diversity as only species which are capable of growing and reproducing in these resource limiting environments can inhabit the area. Additionally, the established species are strong competitors for resources and will exclude, by way of inter-specific competition, weaker competitor species attempting to invade the degraded area. Several studies have demonstrated that with increased species diversity the overall productivity and functionality of the grassland increases. Seedling development and competitive interactions between grass seedlings has a significant impact on the final community structure and species diversity. It is for this reason that aspects of the ecology of grass seedlings were investigated. The growth and competitiveness of Chloris gayana, Cynodon dactylon, Digitaria eriantha, Eragrostis curvula and E. tef seedlings were determined under three environmental stimuli, namely nitrogen availability, light availability and exposure to plant-derived smoke (in the form of smoke-infused water). The primary conclusion from the competition experiments was that the species can be split into superior and inferior competitors at the seedling stage. Chloris gayana, E. curvula and E. tef were the most competitive seedlings as they had the largest negative effect on the growth of other species (high nitrogen Relative Interactive Index (RII) = -0.449, -0.203 and -0.379 respectively) and they were least affected by competition (high nitrogen RII = -0.251, -0.168 and -0.248 respectively). The calculated RII indicates the strength of the competitive interactions, the more negative the RII the stronger the competitive interaction. Nutrient availability had limited effect on the competitive hierarchy of the tested species. Chloris gayana seedlings, however, increased in competitiveness with an increase in available nutrients. In other words, there was a decreased negative response to competition in a high nutrient environment (high nitrogen RII -0.251, no nitrogen RII -0.605). When D. eriantha was grown under varying shade, nutrient and competition levels it was evident that the primary stress factor was light deficiency (p<0.001), and nutrient availability had no affect on seedling growth (p=0.069). Smoke-infused water had no consistent affect on the germination success or the seedling’s root and shoot vigour for the five grasses. These results indicate that the introduction of a “2-phase” or “multi-phase” restoration plan may be beneficial for the development of species diverse rehabilitated grasslands. Manipulating the time and space that the different species are planted, or the distribution of nutrient concentration over the area, may increase the survivorship of all the species that are introduced to a restoration site. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.

Made available in DSpace on 2016-12-23T13:51:47Z (GMT). No. of bitstreams: 1 Fernando Elair Vieira Santos.pdf: 2432736 bytes, checksum: fade743ce95e018f55d2f83efb46016b (MD5) Previous issue date: 2013-07-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A produção de mudas florestais com qualidade está associada entre outros fatores, às características e formulações de cada substrato. Partindo desse princípio, o presente estudo teve por objetivo testar a eficiência do uso de diversos resíduos e vermiculita, associados ao lodo de esgoto como componente e fonte de nutrientes aos substratos para a produção de mudas de Aegiphila sellowiana, e relacionar as características físicas e químicas dos substratos formulados com a qualidade das mudas produzidas. Os substratos foram formulados com diferentes proporções de lodo de esgoto (80, 60, 40 e 20% ) associado à fibra de coco, vermiculita, palha de café in natura, composto orgânico (esterco bovino + palha de café in natura), casca de arroz carbonizada e casca de arroz in natura além de um substrato com 100% de lodo de esgoto e uma testemunha com 100% de substrato comercial. O experimento foi conduzido em um delineamento inteiramente casualizado com 26 tratamentos e cinco repetições de quatro plantas. Foram realizadas análises físicas e químicas dos substratos formulados e dos componentes puros. Após 45 dias da implantação do experimento, foi realizado o raleio das plântulas, permanecendo apenas um indivíduo por tubete. Após 120 da implantação do experimento, foram coletados os dados referentes as variáveis de crescimento, a partir das quais foram obtidos os índices de qualidade. A utilização de diferentes proporções de resíduos contribuiu para a melhoria de algumas propriedades físicas do substrato. O aumento das proporções de lodo de esgoto promoveram diminuição da macroporosidade (Macrop), aumento da densidade global (Dg), água facilmente disponível (AFD), água disponível (AD) e microporosidade (Microp) dos substratos formulados. Em relação as análises químicas, o substrato comercial proporcionou as maiores médias para os teores disponíveis de fósforo, cálcio e magnésio além de condutividade elétrica e teor totais de sais solúveis dos substratos. O lodo de esgoto proporcionou aumento da fertilidade dos substratos com aumento de teores dos nutrientes, principalmente nitrogênio e fósforo, e do teor total de sais solúveis. De acordo com as características apresentadas, foram considerados mais adequados quimicamente para o desenvolvimento de mudas de espécies florestais os substratos formulados com o composto orgânico. As mudas produzidas com maiores proporções de lodo de esgoto resultaram em maiores médias para altura e diâmetro do coleto. Os tratamentos formulados com composto orgânico, especialmente as proporções de 60 e 80%, proporcionaram maiores médias para as características morfométricas avaliadas sendo os mais indicados para a produção de mudas de Aegiphila sellowiana. O substrato comercial proporcionou as menores médias para as características morfométricas avaliadas. Os maiores acúmulos de nutrientes da parte aérea das mudas de Aegiphila sellowiana foram obtidos no tratamento com 40% de lodo de esgoto associado com 60% de composto orgânico. Os nutrientes acumularam na seguinte ordem decrescente de: macronutrientes N>Ca>K>P>Mg>S / The seedling production quality is associated among other factors, the characteristics and formulations of each substrate. Starting from this idea, the recent study had by appointment testing the efficiency of various wastes and vermiculite as a component and nutrients source for the substrates to the production of Aegiphila sellowiana plants looking for decrease the environmental Impact caused by the excess of these ones and connect the physical and chemical points from the substrates formulated with the quality of the produced plants. The substrates were formulated with different ratios of sewage sludge (80, 60, 40 and 20%) associated with coconut fiber, vermiculite, straw coffee fresh, organic compost (manure + straw in nature coffee), bark carbonized rice husk and rice fresh addition of a substrate with 100% sewage sludge and a control with 100% commercial substrate. The experiment was conducted in a completely randomized design with 26 treatments and five replications of four plants. Analyses of physical and chemical substrates formulated and pure components. Within 45 days after the implantation of the experiment was carried out thinning the seedlings, leaving only one individual per pot. Within 120 days after thinning the plants, was studied the variables of growing and indexes of quality. The use of different proportions of waste contributed to the some improvement of physical properties of the substrate. The increase in the proportion of sewage sludge led to a decrease of the macroporosity (Macrop), increased global density (Dg), easily available water (AFD), available water (AD) and microporosity (Microp) substrates formulated. Regarding the chemical analysis the commercial substrate has allowed the biggest averages for the available contents of the substrates. The sewer Iodine has allowed the increasing of fertility from the substrates with increasing of contents from nutrients mostly nitrogen and phosphorus and also the total content of soluble salts. The sewage sludge has allowed the increasing of fertility from the substrates with increasing of contents from nutrients mostly nitrogen and phosphorus and also the total content of soluble salts. According to the presented particularities, were considered more adequate chemically for the plants development from forest species the formulated substrates with the organic compost. The seedlings with higher proportions of sewage sludge resulted in higher means for height and stem diameter. The formulated treatments with organic compost especially with 60 and 80 % proportions, has allowed bigger averages for the morphometric characteristics assessed being the most suitable for the production of seedlings Aegiphila sellowiana. The commercial substrate provided the lowest averages for the morphometric characteristics evaluated. The highest accumulation of the aerial part of the seedlings Aegiphila sellowiana were obtained in the treatment with 40% sewage sludge associated with 60% of organic compost. Nutrients accumulated in the following descending order: macronutrients N> Ca> K> P> Mg> S

Seedlings of two P. rigida and four P. taeda families and six P. x rigitaeda crosses were grown in a greenhouse under two moisture regimes. Water stress decreased growth in every case in every variable measured. Water stress also elicited some genetic differences in the pitch pine and loblolly pine that were not apparent under the non-stressed treatment. The major differences between pitch and loblolly seedlings seemed to be primarily a function of large differences in seed size. Free growth may also play a major role in differences between the two species. The theory that allometric coefficients are a good indicator of growth under moisture stress was not substantiated by this experiment. In addition, k-values were found to remain relatively constant despite changes in moisture stress. It appears that genetic variance components in P. x rigitaeda may have importance under one set of environmental conditions, and be unimportant in another. Inter-relationship of crosses and confounding of genetic expectations, however, make it difficult to speculate which variance components are most important under moisture stress. Correlations were made between seedling growth characteristics and 1, 2, 3, 4, 5 and 7 year height and a 7 year volume index. Many significant correlations were found with 7 year height and volume. These correlations indicate that greenhouse experiments may be useful as an early genetic screening technique in P. x rigitaeda. / M.S.

No description available.

Call number: LD2668 .T4 1984 B425 / Master of Science

Call number: LD2668 .T4 1985 M43 / Master of Science

Call number: LD2668 .T4 1985 M63 / Master of Science

A successful forest generation is important for several operators and a lot can happen on the way from nursery to established plant. Therefore traceability of forest plants is important. Sveaskog is one of Sweden’s big producers of forest plants thru their business Svenska skogsplantor. Today it’s possible to trace forest plants grown by Svenska skogsplantor and planted by Sveaskog, but the chain of traceability cannot be considered unbroken since its partially uncertain under the treatment what happens to the plants. Today systems with barcodes, computer systems and applications in smartphones can be at help to create unbroken chains of traceability and the purpose of this work was to examine of what an extended traceability of forest plants could be. The work was done with qualitatively method and semi-structured interviews and the result show that people who work with establishment of forest plants where satisfied with the current traceability but could see benefits like increased control, more interesting work and substratum for statistics as good usage from improved traceability.

Thesis (MScAgric)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: The influence of chemical seed treatments on the germination, seedling survival and yield of canola (cv. Varola 44) was investigated in a series of incubation studies, glasshouse experiments, as well as field trials in the canola producing areas in the Western Cape Province. Incubation experiments were conducted to compare germination and seedling growth of untreated (control) seed with that of seed treated at different application rates (0.5, 1.0 and 2.0 times the recommended) of Cruiser® and SA-combination (which consists of Thiulin® at 0.5g a.i.; Apron® at 0.0815 g a.i.; Gaucho® at 0.6125 g a.i. and Rovral® at 0.9975 g a.i.). The results indicated that seed treatment (all rates of SA-combination and highest rate of Cruiser) delayed germination and seedling growth, especially if the seed was subjected to the Accelerated Ageing Test. Glasshouse studies with pasteurised soil at different water contents, seed sources (storage periods) and planting depths confirmed the phytotoxic effects of the chemical seed treatments in the absence of soil borne pathogens. From the results it became clear that extreme water conditions (very wet or dry) increased the suppressing effect on germination and seedling growth, but that no phytotoxic reactions occurred in moist (favourable soil water conditions) soil, regardless of application rate of the chemicals used, planting depth and seed source. In a second glasshouse experiment conducted in moist soil (kept at 50% of field water capacity to prevent any toxic effects) from seven different localities that were naturally infested with pathogens, both chemicals proved to be effective where soil borne pathogens (Rhizocfonia so/ani and Pythium spp.) occurred. No clear trend could however be found due to either chemical or application rates used. Finally, field trials were conducted to study the effect of chemical seed treatments on the plant populations and yield of canola planted in different row widths (17 and 34 cm) and seeding rates (3, 5 and 7 kq.ha'). Results showed that treated seeds produced more plants.rn" and yielded more than untreated seeds at Roodebloem Experimental Farm, while the highest seeding rate produced significantly more plants.rn" (Roodebloem and Langgewens Experimental Farms), but not significantly higher yields than the lowest seeding rate at the same locality. Although row width did not have an effect on plant population, yield (Roodebloem 2003) was significantly less at the wider (34 cm) rows. As in earlier experiments, no consistent differences between the two chemicals used were found. These results clearly illustrated both the negative (in the absence of pathogens) and positive (where soil borne pathogens do occur) effects that chemical seed treatments may have on the germination, seedling growth and even yield of canola under local environmental and soil conditions. Because no significant differences were found between the chemicals used, both chemicals should be regarded as efficient. More research, especially under field conditions and with more cultivars, is needed before the registration of a chemical for seed treatment could be considered. / AFRIKAANSE OPSOMMING: Die invloed van chemiese saadbehandeling op die ontkieming, saailing oorlewing en opbrengs van canola (cv. Varola 44) is ondersoek in 'n reeks inkubasie studies, glashuis eksperimente en veldproewe in die canolaproduserende gebiede in die Wes Kaap Provinsie. Inkubasie eksperimente is uitgevoer om die ontkieming en saailing groei van onbehandelde (kontrole) saad te vergelyk met dié van saad wat behandel is teen verskillende dosisse (0.5, 1.0 en 2.0 keer die aanbevole) van Cruiser® en SA-kombinasie (wat bestaan uit Thiulin® teen 0.5g a.i.; Apron® teen 0.0815 g a.i.; Gaucho® teen 0.6125 g a.i. en Rovral® teen 0.9975 g a.i.). Die resultate het aangedui dat saadbehandeling (vir alle dosisse van SAkombinasie en die hoogste dosis van Cruiser) ontkieming en saailing groei vertraag, veral wanneer die saad onderwerp was aan die Versnelde Verouderings Toets. Glashuis studies met gepasteuriseerde grond by verskillende waterinhoude, saad bronne (stoor periodes) en plantdieptes, het die fitotoksiese effekte van die chemiese saadbehandelings bevestig in die afwesigheid van grondgedraagde patogene. Vanuit die resultate het dit duidelik geword dat ekstreme water toestande (baie nat of droog) die onderdrukkende effek op ontkieming en saailinggroei verhoog het, maar dat geen fitotoksiese reaksies plaasgevind het in klam (gunstige grondwater toestande) grond nie, ongeag die dosisse of chemikalieë gebruik, plantdiepte en saad bron. In 'n tweede glashuis eksperiment uitgevoer in klam grond (gehou by 50% van veldwaterkapasiteit om toksiese effekte te voorkom) van sewe lokaliteite wat natuurlik besmet was met patogene, was beide chemikalië effektief waar grondgedraagde patogene (Rhizoctonia so/ani en Pythium spp.) voorgekom het. Geen duidelike tendens is egter waargeneem vir enige van die chemikalieë of dosisse nie. Laastens is veldproewe uitgevoer om die effek van chemiese saadbehandelings op plant populasies en opbrengs te bepaal van canola geplant in verskillende rywydtes (17 en 34 cm) en saaidigthede (3, 5 en 7 kg.ha-1). Resultate het aangedui dat behandelde saad meer plante.rn" produseer en 'n groter opbrengs lewer as onbehandelde saad by Roodebloem Eksperimentele Plaas, terwyl die hoogste saaidigtheid betekenisvol meer plante.m" (Roodebloem en Langgewens Eksperimentele Plase), maar nie betekenisvol hoër opbrengste gelewer het as die laagste saaidigtheid by dieselfde lokaliteit nie. AI het rywydte nie 'n effek op plant populasie gehad nie, was opbrengs (Roodebloem 2003) betekenisvol minder by die wyer (34 cm) rye. Soos in vroeëre eksperimente is geen konsekwente verskille tussen die twee chemikalieë gevind nie. Hierdie resultate illustreer duidelik beide negatiewe (in die afwesigheid van grondgedraagde patogene) en positiewe (in die aanwesigheid van grondgedraagde patogene) effekte wat chemiese saadbehandelings op ontkieming, saailing groei en selfs opbrengs van canola onder plaaslike omgewings en grondtoestande kan hê. Omdat geen betekenisvolle verskille tussen die chemikalieë gevind is nie, moet beide chemikalieë as doeltreffend aanvaar word. Meer navorsing, veralonder veldtoestande en met meer kultivars, is egter nodig voordat die registrasie van 'n chemiese middel vir saadbehandeling oorweeg kan word.