Digital Commons Network^™

Ecological Database Development And Analyses Of Soil Variability In Northern New England, Michael Anayo Okoye

Doctoral Dissertations

The 1983 Forest Inventory and Analysis (FIA) data of the states of Maine, New Hampshire and Vermont (the study area) contain large amounts of field-measurements of many ecologically important variables. Despite the vast potential usefulness of the FIA data for scientific research, the data were until now, literally unused except for a few administrative purposes, because of problems in the way the data were organized, summarized, and coded for storage. The primary objective of this research was to solve the problems that had thus precluded these FIA data from use in scientific applications, and present the data in a form …

Relationship Of Critical Photoperiod Of Short-Day Parents To Frequency Of Day-Neutral Progeny In Short-Day X Day-Neutral Crosses Of Fragaria X Ananassa, Christina Marie Cundari

Doctoral Dissertations

Critical photoperiod for flowering was determined for short-day (SD) and day-neutral (DN) genotypes of strawberry used in SD x DN crosses to investigate whether variation in critical photoperiod contributes to variation in frequency of DN progeny and, hence, may be an effective selection criterion for screening SD genotypes for use as parents in breeding regionally-adapted DN cultivars. Twelve SD and four DN genotypes were grown in controlled environments under eight photothermal regimes (four photoperiods (9, 11, 13, 15 hr) x two day/night temperatures (19/14 and 24/19$\sp\circ$C)). Among the SD genotypes, critical photoperiod varied more under cool than warm regimes. Under …

Characterization And Inheritance Of The Fused Vein Trait In Squash (Cucurbita Pepo L), Robert Bruce Carle

Doctoral Dissertations

This investigation characterized and determined the inheritance of the fused vein trait in Cucurbita pepo L. with the purpose of evaluating its use as a rouging marker for hull-less seeded cultivars.

The trait is characterized by the partial fusion of the primary leaf veins. There is a reduction in the intraveinal leaf blade and the dorsal leaf surface appears wrinkled. Depending on genetic background, fusion begins with the fourth to tenth leaf stage and continues throughout vegetative growth. The extent of fusion also varies from slight (1-5 cm) to pronounced (15-20 cm). Anatomically, fusion results from an interruption of vein …

Gametophytic Selection For Early Maturity In Tomato (Lycopersicon Esculentum Mill), Mark Lawrence Crispi

Doctoral Dissertations

The feasibility of applying low temperature as a screen for selecting early gametes during pollination of tomato flowers was investigated. Pollen germination and tube growth on solidified agar were evaluated at 8, 15, or 25 C after 6, 12, 18, or 24 hours of incubation for two early-, two intermediate-, and two late-maturing tomato cultivars. Pollen from early cultivars showed superior germination and tube growth at 25 C, whereas pollen germination and tube growth of late cultivars were greatest at 15 C. Pollen germination and tube growth of the two early and two late cultivars were evaluated at three (three …

Rowcover Modification Of Carbon And Mineral Nutrient Partitioning In Strawberry (Fragaria Ananassa, Duch), Karen Lynn Brownlee Gast

Doctoral Dissertations

In cool temperature climates where plant growth may be limited by short growing seasons and low temperature stress rowcovers are being used to increase production of fruit and vegetable crops. Two field experiments were conducted to investigate how floating rowcovers applied during autumn, winter and spring affect plant growth and development. The first experiment, 1985-86, examined mineral nutrient and biomass partitioning in a short-day cultivar, 'Sparkle', and a day-neutral cultivar, 'Fern', in rowcovered and nonrowcovered plants in autumn. The second experiment, 1986-87 examined carbon, nitrogen and biomass partitioning over time in autumn and in spring and development of yield components …

Characterization Of Sod-Induced Alfalfa Seedling Injury (Allelopathy, Anaerobiosis), David James Lang

Doctoral Dissertations

Field and greenhouse studies were conducted to examine the seedling vigor of sod-sown alfalfa (Medicago sativa L.).

Seedlings grown in tilled soil had more dry matter, were taller, and had longer internodes than seedlings in sod. Node number and plant density were reduced in some experiments. Seedling vigor was not hindered by physical impairment of seed germination, inadequate soil fertility, weed or sod competition, soil moisture, herbicide injury, or predators.

Time interval between tillage of sod and planting date affected seedling vigor. Seedlings growing in sod tilled the previous fall had higher yields than those sown in freshly tilled sod …

Physiology And Persistence Of Alfalfa With Changes In Soil Chemistry, Desta Beyene

Doctoral Dissertations

The influence of liming on soil chemical changes and on nodulation, nitrogen fixation and yield of alfalfa was investigated.

In the field, increasing rates of lime improved alfalfa dry matter yield at the Kingman Farm. Optimum dry matter yield was obtained with 3.5 tons lime/ha. A quadratic response curve showed that liming accounted for about 70 percent of the yield variation in alfalfa. Herbage N, P and Mg increased in response to liming six years after establishment. The simple correlations between dry matter yield and plant N, plant P and Plant Mg were positive and significant. Plant Al and Mn …

No-Tillage Renovation Of Alfalfa Stands, George William Mueller-Warrant

Doctoral Dissertations

The effects of herbicides, timing, and rates on the introduction of alfalfa (Medicago sativa L.) into six stands of alfalfa at varying stages of decline were investigated.

Alfalfa was seeded on several dates from 25 April through 28 May 1979 with a Tye Pasture Pleaser('R) no-till seeder. G.

Growth, Nodulation And Nitrogen Fixation Of Alfalfa (Medicago Sativa L) And Red Clover (Trifolium Pratense L) As Influenced By Soil Acidity And Liming, Daniel Stewart Thomas Roberts

Doctoral Dissertations

A series of field, greenhouse and laboratory experiments were conducted to examine the influence of soil acidity and liming on the growth of Rhizobium and the nodulation, nitrogen fixation, and yield of alfalfa and red clover.

In the greenhouse, from soil pH 5.0 to 5.6, nitrogen fixation was shown to be more correlated to Al saturation than pH or available P. Once Al saturation was reduced to less than 5 percent by liming, the application of P was more beneficial to yield and nodulation than further application of lime. Lime pelleted alfalfa seed sown at a soil pH of 5.0 …

Varietal Response Of Maize (Zea Mays L) To Temperatures, Planting Dates, And Locations, Suk Soon Lee

Doctoral Dissertations

No abstract provided.

Physiological Factors Affecting The Differential Uptake And Accumulation Of Phosphorus By Long And Short Season Genotypes Of Maize, Theodore Frank Bruetsch

Doctoral Dissertations

No abstract provided.

The Preparation, Characterization And Agricultural Use Of Bark-Sewage Compost, Raymond Henry Walke

Doctoral Dissertations

No abstract provided.

Variation In Stomatal Length And Frequency And Its Relationship To Leaf Characteristics And Yield In Bromus Inermis Leyss, Tan Geok-Yong

Doctoral Dissertations

No abstract provided.

Bioassay Tests From Leaf Diffusates Of Helminthosporium Turcicum On Zea Mays, Alfonso G. Calub

Doctoral Dissertations

No abstract provided.