Mémoire (M.Ress.Renouv.)-- Université du Québec à Chicoutimi, 1993. / Document électronique également accessible en format PDF. CaQCU

Mémoire (M.Ress.Renouv.)--Université du Québec à Chicoutimi, 2001. / Document électronique également accessible en format PDF. CaQCU

Thèse (M.Ress.Renouv.) -- Université du Québec à Chicoutimi, 2004. / Bibliogr.: f. [72]-78. Document électronique également accessible en format PDF. CaQCU

Thèse (M.Ress.Renouv..) -- Université du Québec à Chicoutimi, 2006. / Bibliogr.: f. 40-52. Document électronique également accessible en format PDF. CaQCU

Inaug.-Diss.--Sofia. / Bibliography: p. [35]-38.

Thesis (MSc)--Stellenbosch University, 2001. / ENGLISH ABSTRACT: A total of 125 trees covering a range of tree diameters were selected from a progeny trial of open pollinated progenies of Pinus patuia for studies on trait assessments and evaluation for branching characteristics. The trees comprised 25 families with each family having five trees. The trial was 36 months old and was located in a relatively high yielding site in Block B at Usutu in Swaziland. The height, diameter, the number of branches and the number of whorls of each tree were recorded. In addition to these objective assessments on individual trees, trees were given scores for branch size, branch angle, stem straightness and crown coarseness. For the detailed branch evaluation study, trees were marked at 20% and 50% of the total tree height and the section between this range was used. On this section the internode length, the internode diameter, the branch diameter and the branch angle were measured. It was observed that the objective assessments correlated strongly with the scoring (subjective) and it was further recommended that a closer look is needed to consider the prospects of employing subjective assessments as a means of reducing costs incurred during objective trait assessments. The branch sampling study revealed that there were prospects of assessing fewer branches on a tree as opposed to assessing all the branches, which could be a major contributor to the high costs in tree breeding. All three methods used to explore this prospect showed some reasonable agreement with each other in this regard. The best sample is to measure all branches in whorl one and two above 20% tree height followed by sampling four branches, two from the first whorl and two from the second whorl. There is a slight difference in these two samples as determined by the coefficents of determination. The study recommends that four branches can be used in the assessment of the branch angle and the branch diameter on the trees when one considered the cost elements. / AFRIKAANSE OPSOMMING: In 'n ondersoek na die evaluering van tak-eienskappe van Pinus patuIa is 125 bome in 'n oop-bestuifde nageslags-proef geselekteer. Hierdie bome is gekies met groottes wat strek oor 'n wye verskeidenheid van borshoogtedeursnee. Die ondersoek het 25 families ingesluit met elke familie wat uit 5 bome bestaan. Die proef is 36 maande oud en is gevestig in'n hoë produksiearea van Blok B, Usutu, in Swaziland. Die hoogte, borshoogtedeurnee, aantal takke en die hoeveelheid takkranse is gemeet en bepaal by elk van die 125 bome. Verder is punte toegeken vir takgrootte, takhoek, graad van stamkromming en kroon grofheid. In die gedetailleerde tak-evaluasie is slegs die stamseksie tussen 200!o en 50% van die totale boomhoogte gebruik. Op hierdie seksie van die boomstam is die internodale afstand, die internodale deursnee, die takdeursnee en die tak-hoek gemeet. Uit die gegewens wat versamel is, het dit geblyk dat daar sterk korrelasie tussen die objektiewe evaluasie en die subjektiewe evaluasie (met gebruik van kwalitatiewe eienskappe op 'n tellingbasis) verkry is. Hieruit word aanbeveel dat meer aandag aan subjektiewe evaluasie (as vereenvoudigde evaluasieprosedure) bestee word om kostes te besnoei. Die gedetailleerde tak-evaluasiestudie het aangedui dat die gebruik van slegs 'n paar takke, in teenstelling met al die takke op die boom, voordelig kan wees om verdere kostes van evaluasie te bespaar. Die beste monster is om al die takke in die eerste twee takkranse bo 20% boomhoogte te meet. Daarnaas is die beste monster die eerste twee grootste takke in die eerste en tweede takkranse. Die gebruik van hierdie kleiner monsters vir evaluering het in sekere opsigte nog beter voorspellings gelewer as in die gevalle waar al die takke in die eerste takkrans gebruik is. Die studie b aan dat In betroubare monster van vier takke (twee uit elke takkrans bo 20% boomhoogte) geneem kan word om die boom se takeienskappe te be-oordeel.

No description available.

Sugarcane plants (cultivar NCo376) were studied to assess the effects of temperature and season (spring and autumn equinox) on the morphological and physiological response of stalk components. Plants were grown from single-eyed setts for ca. five months and then placed into three temperature controlled glasshouses (22/12°C (C), 27/17°C (W) and 32/22°C (H) day/night temperatures). The plants were sampled twice weekly over a one month period., and intemodes 4, 6 and 10 of the primary haulms of each plant sampled for growth and sugar analysis. During spring, the leaf emergence rates were 0.0303, 0.1095 and 0.1682 leaves d(-1) at temperatures C, W and H, respectively; and 0.0327, 0.0824 and 0.113 leaves d(-1) in autumn. The phyllochron intervals were 114°Cd in spring and 147°Cd in autumn. Highest green leaf blade area of the primary haulms was achieved at H (438.0 and 511.7 cm2 in spring and autumn, respectively). The stalk extension rates were 1.22, 1.02, 0.38 cm d(-1) (spring) and 1.35, 0.98, 0.45 cm d(-1) (autumn), respectively, in descending order of temperature. Total biomass and stalk biomass per plant were not affected by temperature, despite the differences in stem elongation. Internodes of plants at C were shorter but thicker and heavier than the comparable internodes of plants at W and H. In autumn, the mature internode sucrose concentrations were 35.5, 29.2 and 25.5% at C, W and H, respectively; corresponding to mean RS% of 5.7, 9.8 and 13.3%, and fibre % of 58.8, 61.1 and 61.3%, at the respective ascending order of temperature. Sucrose % in the mature internodes in spring were 27.8, 20.9 and 19.9% at C, W and H, respectively; corresponding to RS% of 5.9, 9.76 and 10.9% and fibre % of 66.3, 69.4 and 69.2% at the respective ascending order of temperature. Temperature effect on the concentration of the stalk components of the immature internodes was in general not significant. Sucrose partitioning coefficients in the mature internodes were 0.25, 0.21 and 0.20 in spring and 0.50, 0.32 and 0.21 in autumn (at C, W and H, respectively). Data that resulted from this study, which is isolated to temperature and cultivar NCo376 can be used in models of sugarcane that simulate leaf appearance and senescence, assimilate partitioning between leaf and stalk and assimilate partitioning between the stalk components namely sucrose, reducing sugars and fibre. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

Mémoire (M.Ress.Renouv.)--Université du Québec à Chicoutimi, 1998. / Document électronique également accessible en format PDF. CaQCU

Mémoire (M.Ress.Renouv.)--Université du Québec à Chicoutimi, 1998. / Document électronique également accessible en format PDF. CaQCU