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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
171

Environmental and genetic control of heterostyly in tomato (Lycopersicon esculentum L.) /

Thakur, Milkhi Ram January 1970 (has links)
No description available.
172

The relationship between metribuzin injury and peroxidase in tomato cultivars /

Aclan, Francisco January 1976 (has links)
No description available.
173

An analysis of the return-risk tradeoffs associated with tomato production in northwestern Ohio /

Schurle, Bryan Wilfred January 1977 (has links)
No description available.
174

Studies on carbon monoxide production by ripening tomato fruits /

Gladon, Richard Joseph January 1977 (has links)
No description available.
175

Effect of metribuzin on growth, development, yield, quality, chlorophyll content of leaves and mineral composition of leaves and fruits of tomato (Lycopersicon esculentum Mill.) /

Mohamed, Seif El Din Fageer January 1978 (has links)
No description available.
176

Effect of night air temperature, root-zone heating, carbon dioxide enrichment and viterra hydrogel amendments on the greenhouse tomato (Lycopersicon esculentum Mill.) /

Carter, Johnny January 1978 (has links)
No description available.
177

The use of fluoresecent mold counting methodology for the enumeration of fungi in tomatoes for processing /

Fox, James Gillen, January 1979 (has links)
No description available.
178

Nematodes, bacteria and their interrelationships in the crown-gall disease of tomatoes.

Chong, Kuang-Yin. January 1973 (has links)
No description available.
179

Salmonella Internalization From Contaminated Seeds or Irrigation Water in Greenhouse Tomatoes

Miles, Jacquelyn Marie 20 December 2006 (has links)
Greenhouse grown tomato fruits and tissues were tested for the presence of Salmonella after the plants had been treated with Salmonella contaminated irrigation water or grown from contaminated seeds. Greenhouse grown tomato plants were placed into eight different groups. Groups one through six consisted of five plants each and were treated with 350 ml of 10^6 Salmonella contaminated irrigation water over a course of 70 days; group one received one 350 ml 10^7 Salmonella treatment, group two received two treatments, and so on, the treatments were scheduled every 14 days. Group seven was the control that consisted of five plants and received no Salmonella treatment. Group eight was grown from seeds that had been contaminated with Salmonella by soaking the seeds in a 10^8 Salmonella suspension for 24 hours at room temperature, and received no Salmonella watering treatment. A total of 128 tomatoes were sampled from the tomato plants of all three groups and none tested positive for Salmonella. Tissue samples consisting of roots, leaves, and stems, and were collected from one plant per each of three replications. No leaves or stems contained Salmonella, however, five of the twenty-four root samples were positive for Salmonella. In a second study, Salmonella was tested for its ability to survive in three concentrated fertilizer stock solutions and 1.6% diluted solutions of the fertilizer. Fertilizer sample CF-S was a stock solution of commercial 20N-4.4P-16.6K fertilizer, US-S was a mix of 11.3 kg UltraSol, 4.5 kg Epsom Salts, and 2.3 kg 0N-0P-43.2K in 114 L water, Fertilizer CN-S is a mix of 11.3 kg Calcium Nitrate and 56.7 g Iron chelate (10%) to 30 L water; Fertilizers CF-1.6, US-1.6, and CN-1.6 were the 1.6% fertilizer dilutions respectively. There was no significant difference (p<0.05) between the survival of Salmonella in fertilizer groups CF-1.6, US-S, US-1.6, CN-1.6, and the sterile distilled water control; all but US-S yielded less than a one log reduction in Salmonella over a period of 72 hours. US-S yielded over a two log reduction in Salmonella and was not significantly different than CN-S which had over a four log reduction. CF-S was significantly different than all samples and led to over a 6 log reduction of Salmonella. The results of this study showed no evidence that Salmonella was able to internalize in Cultiver trust tomato fruit or tissues above the root line when irrigated with contaminated water into the pine medium under greenhouse conditions. There was also no evidence that Salmonella is able to internalize in any tissues or fruit from contaminated seeds. The results also show that Salmonella was not able to survive in the commercial fertilizer stock solution (CF-S), and had limited survival in CN-S tomato fertilizer solution. The diluted fertilizer solution and US-S stock solution showed no significance in survival of Salmonella when compared to the sterile water control. / Master of Science in Life Sciences
180

Physiological and metabolic factors determining nitrogen use efficiency of tomato seedlings grown with elevated dissolved inorganic carbon and different nitrogen sources

Viktor, Aleysia 03 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: The aim of this study was to determine (l) the influence of elevated dissolved inorganic carbon (DIC) on the nitrogen use efficiencies (NUE) of tomato seedlings grown with different nitrogen sources, (2) how changes in the regulation and activities of nitrate reductase (NR), phosphoenolpyruvate carboxylase (PEPc), carbonic anhydrase (CA) and subsequent changes in metabolites would account for observed changes in NUE, and (3) to what extent elevated DIC contributed to the carbon budget of plants grown with different nitrogen sources. Lycopersicon esculentum cv. Fl44 seedlings were grown in hydroponic culture (pH 5.8) with 2 mM of either N03- or NH4 + and the solutions were aerated with either 0 ppm or 5000 ppm CO2 concentrations. The similar NUEs of NH/-fed plants grown with either root-zone CO2 concentration were largely due to their similar RGRs and N uptake rates. Elevated root-zone DIC had an initial stimulatory effect on N~ + uptake rates, but it seems as if this effect of DIC physiological processes was cancelled out by the toxic effect of unassimilated NH/. The NUE for N03--fed plants supplied with 5000 ppm root-zone CO2 was higher relative to 0 ppm root-zone CO2 and it was possibly due to the higher relative growth rates for similar N uptake rates of 5000 ppm compared to 0 ppm root-zone CO2. Nitrate-fed plants grown with 5000 ppm compared to 0 ppm root-zone CO2 had higher in vivo NR and in vitro NR and PEPc activities. These increases in enzymes activities possibly lead to increases in organic acid synthesis, which could have been used for biomass accumulation. This would account for the increased relative growth rates of N03--fed plants grown with 5000 ppm compared to 0 ppm root-zone CO2. The increasing rootzone CO2 concentrations resulted in the Ó15N values of NH/-plants becoming more positive indicating an absence of enzymatic discrimination. This may have been due to the inhibitory effect of DIC on Nll,+ uptake, causing plants to utilise both internal isotopes equally. The Ól3C studies showed that PEPc contributed equally to both N03-- and NH/-fed plants over the long term. From this it can be concluded that the lower NUE of NH/-compared to N03--fed plants grown with 5000 ppm root-zone C02 was due to increased N uptake and exudation of organic compounds into the nutrient solution. Experiments with 813C also showed that at increasing rootzone CO2 concentrations, PEPc made a bigger contribution to the carbon budget via the anaplerotic reaction. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om (1) die invloed van verhoogde opgeloste anorganiese koolstof dioksied (DIC) op die stikstofverbruiksdoeltreffenheid (NUE) van plante wat op verkillende stikstofbronne gekweek is, te bepaal. (2) Veranderinge in die regulering van nitraat reduktase (NR), fosfo-enolpirovaatkarboksilase (PEPc) en karboonsuuranhidrase (CA) is bestudeer en gekorreleer met waargeneemde verskille in NUE. (3) 'n Beraming van die mate waartoe verhoogde DIC bydra tot die koolstofbegroting van plante, gekweek op verskillende stikstofbronne, word bespreek. Lycopersicon esculentum cv. F144 saailinge is in waterkultuur (pH 5.8) met 2 mM N03- of NH/ gekweek en die oplossings is alternatiewelik met 0 ppm of 5000 ppm CO2 belug. Die NUEs van plante gekweek met NH/ en belug met albei C02 konsentrasies was vergelykbaar grootliks as gevolg van hulooreenkomstige relatiewe groeitempo's en Nopname. DIC het aanvanklik NH/ opname gestimuleer, maar enige latere stimulerende effek van DIC op fisiologiese prosesse was klaarblyklik uitgekanselleer deur N~ + toksiteit veroorsaak deur vertraagde assimilasie. Die NUE van plante gekweek met N03- en 5000 ppm CO2 was hoër as dié van plante gekweek met N03- en 0 ppm CO2. Dit is moontlik gekoppel aan hoër relatiewe groeitempo's teenoor onveranderde N opname tempo's. Plante gekweek met N03- en 5000 ppm CO2 het hoër in vivo NR en in vitro NR en PEPc aktiwiteite getoon as plante gekweek met N03- en 0 ppm CO2. Bogenoemde toenames in ensiem aktiwiteite word verbind met biomassa toename deur verhoogde organiese suur sintese. Dit bied 'n moontlike verklaring vir die hoër relatiewe groeitempo's van plante gekweek met N03- en 5000 ppm CO2 teenoor plante gegroei met N03- en 0 ppm CO2. Die 015N waardes van plante gekweek met NH/ en 5000 ppm CO2 was meer positief as dié van plante gekweek met Nl-l,+ en 0 ppm CO2 wat gedui het op die afwesigheid van ensiematiese diskriminasie. Dit kon as gevolg gewees het van die vertragende effek van DIC op Nl-la + opname wat daartoe sou lei dat die plante beide isotope eweveel inkorporeer. Eksperimente met ol3C het getoon dat PEPc oor 'n lang tydperk eweveel begedra het tot die koolstofbegroting van plante gekweek met beide N03- and N~+. Hiervan kan afgelei word dat die laer NUE van plante gekweek met NH4 + en 5000 ppm C02 in vergelyking met dié van plante gekweek met N03- en 5000 ppm CO2 die gevolg was van verhoogde NH/ opname en uitskeiding van aminosure in die voedingsoplossing. Eksperimente met 0"c het ook getoon dat verhoogde DIe konsentrasies die bydrae van PEPc tot die plant se koolstofbegroting laat toeneem.

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