Thesis (M.S.)--University of Wisconsin--Madison, 1961. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 18-19).

An interlocking group of studies was conducted to examine the effects of row covers and plant population density on the growth and productivity of field-grown bell peppers. The studies were carried out at the Agriculture Canada Research Station, Agassiz, British Columbia, in 1988. Analysis of variance was used to determine treatment effects on reproductive and vegetative components of yield. A nonlinear regression model was used to define the yield responses. Yield components were assessed, at different stages of plant growth, for their contribution to reproductive and total plant yield variation, using a two-dimensional partitioning technique. The influence of growth and treatments on fruit and whole plant allometry was studied using a best subset multiple regression procedure. Row covers enhanced reproductive and vegetative yield per plant and per land area. Increasing plant population densities resulted in decreasing yield per plant, but increasing yield per land area. Furthermore, the effect of row covers on yield was greater at low population densities than high. The number of nodes was the most important contributor to variation in reproductive and total plant yield. Fruit weight as a proportion of total plant yield was also a major contributor to reproductive yield. The analysis showed the importance of row covers in the initial stages of growth, and the increasing importance of plant population density as growth proceeded, on yield components and on reproductive and total plant yield. Allometric relationships defining fruit and plant morphology changed during growth, and were also affected by row covers and plant population density. The changes were reflected through the allometric exponent and the allometric coefficient. Significant increases in horticultural yield resulted from the application of row covers and from high plant population densities. The response was quantified in mathematical models. Yield component analysis and allometric analysis of reproductive and total plant yield, proved to be valuable techniques for extending our understanding of plant growth relations resulting from the applied treatments. / Land and Food Systems, Faculty of / Graduate

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Thesis (M.Sc.(Agric.))(Plant Production)--University of Pretoria, 2004. / Includes summary Includes bibliographical references. Available on the Internet via the World Wide Web.

Graduation date: 1980

Thesis (Ph. D.)--University of Florida, 1982. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 147-155).

Pepper (Capsicum annuum L.), which originates from tropical environments is particularly sensitive to low temperatures. The Canadian climate, with its risks of cool temperatures during spring time, greatly limits the production of this temperature-sensitive crop. This work dealt with pepper plant exposure to low temperatures (9 and 15$ sp circ$C), at two early growth stages. 'Lady Bell' pepper plants were grown from seed under controlled conditions of 21$ sp circ$C, 50 $ pm$ 10% R.H., 16/8 light/dark cycle and 300 $ mu$molm$ sp{-2} / rm s sp{-1}$ PAR at the canopy level. Once plants had reached either the cotyledonary or the three-true-leaf stage low temperatures were applied. Treatment conditions lasted until plants had produced three additional leaves after which they were returned to the pretreatment conditions. Evaluations were made at six recognized developmental stages and included destructive measurements for growth analysis, pigment content and leaf anatomical features as well as weekly non-destructive measurements. Results showed that plant responses to 9 and 15$ sp circ$C were not the same when applied at the cotyledonary or the three-true-leaf stage. Overall growth decreased with decreasing temperatures and plants exposed to 9$ sp circ$C at the cotyledonary stage died. Plants exposed to cold treatments underwent a whole complex of changes in morphology which included reduction in leaf size, stem diameter, internode length and on leaf, branch and developing fruit abnormalities. Dry matter accumulation and distribution, leaf area production and leaf pigment levels varied with treatments. The anatomical changes which included alterations in epidermal and mesophyll cell dimensions and arrangement were reminiscent of a general response to a wide range of stress conditions reported for several other plant species. Upon return to the control temperature recovery was clearly observed especially in those plants exposed to the 15$ sp circ$C treatments. Plants ex

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