No description available.

No description available.

Tris-soluble protein and total nitrogen of tall and dwarf tomato (Lycopersicon esculentum Mill.) seedlings were determined by the method of Lowry et al. and a modified micro-Kjeldahl direct Nesslerization technique. The tall tomato 'Fireball' differs from the dwarf 'Md. 412-4' in several ways: (1) the tall has more total nitrogen and protein; (2) it exhibits a significant increase in protein during the initial 48-hours of seeds imbibition; (3) it has a higher amount of protein in the roots; (4) the rate of decline of total nitrogen is faster than the dwarf, and (5) the tall tomato is more efficient in the utilization of plant nitrogen and protein. The greater growth of the tall resulted in a more rapid decline in nitrogen. However, in 10-18 day-old seedlings, growth was still rapid while nitrogen and protein did not change appreciably. The tall was more efficient and utilized a lesser amount of nitrogen and protein in the production of a comparable amount of fresh weight. It is suggested that the roots have considerable influence(s) on the growth of the shoot and that the decline in nitrogen and protein is a resultant of growth. It is indicated that the differences in growth may be more dependent on the manner in which nitrogen and protein are utilized rather than their absolute content. / Master of Science

Media containing Weblite were compared to various media for its effectiveness in germination, plant growth and rooting. The 2M media were compared by determining the percentage germination and the dry weight after U2 days of Lycopersicon esculentum cv Better Boy, grown to transplant size. These media were composed of various proportions and combinations of Weblite, vermiculite, Jiffy Mix, peat moss and sand. The available moisture, porosity,field capacity and permanent wilting point of these 2b media were determined. This information was compared with the results from the germination and growth study of tomato plants. Weblite was a constituent of the seven best media for germination. Tomato plants grown in media containing vermiculite had the highest dry weights. Chrysanthemum morifolium cv Sunny Mandalay stem cuttings were rooted in six media. These media were composed of various proportions and combinations of sand, peat moss, Weblite, and perlite. Their root system and foliage condition were evaluated 18 days later. Weblite was significantly better in rooting Chrysanthemums than the six other media.Dianthus caroyphyllus cv Caribe stem cuttings were rooted in nine media. These media were composed of various proportions and combinations of sand, peat moss, Weblite. perlite, and vermiculite. Their roots, stem and foliage condition were evaluated 26 days later. The best root system developed in media with vermiculite as its main constituent. / Master of Science

Experiments to evaluate the effects of tillage systems and nitrogen fertilizer rates on fresh market 'Pik Red' tomato (Lycopersicon esculentum Mill.) production were carried out at Blacksburg, Virginia (1981 and 1982) and at Carrasco and Jackson, Uruguay (1981-2). Two tillage systems were used: (a) conventional tillage (CT) - plowed, disced and rototilled, and (b) no-tillage (NT) using paraquat at 0.5 kg/ha. Four different nitrogen (N) rates were used: 40, 80 and 120 kg N/ha broadcast at transplanting and a 40/40 kg N/ha split applications - 40 kg N at transplanting and another 40 kg N after the flowers of the first cluster had set. During 1982, at Blacksburg a 0 kg N/ha rate was added. For all locations and years, water availability was equal or higher in NT plots than with CT after transplanting. The largest differences were found at the beginning of the growing season. Soil under NT tended to be cooler than under CT; these differences in soil temperature are attributed to higher moisture content with NT than CT and the shading effect of the mulch in the NT plots. Soil Nitrate (NO3) content was equal or lower with NT than with CT at Carrasco and Jackson. Absorption of NO3 by the rye cover crop in NT plots probably was a major cause of NO3 differences between tillage systems. Nitrogen, P and K content in leaf tissue were equal or higher while Ca and Mg were equal or lower in NT plants than in CT plants. Nitrogen tissue content was increased by the N rate only at Carrasco; no effect of N rate was found on absorption of other nutrients at Carrasco or Jackson. Total yield was not affected by the tillage systems except for Blacksburg in 1982 when the NT plots outyielded CT plots. Marketable yield was consistently increased by the NT system at all locations and years. Unmarketable yield was equal or higher with CT than with NT. No effect of the N rate was found for any yield or yield components except for Blacksburg in 1981 where the total average weight was affected by the N rate. Water availability rather than N supply is believed to be the limiting factor to yield production at all locations and years. Blossom-end rot was consistently reduced by the NT system at all locations and years. Improved water availability with NT than with CT was probably responsible for a more steady Ca supply to growing fruit with NT than with CT, thus reducing the incidence of the disorder. / Ph. D.

No description available.

No description available.

No description available.

O presente trabalho teve como objetivo estudar os efeitos da radiação ionizante em tomates (Lycopersicum esculentum Mill) e paralelamente avaliar a influência da irradiação sobre o teor de licopeno de um molho preparado com estes frutos irradiados. Para tanto os tomates foram submetidos a cinco tratamentos: controle, T1 (0,25 kGy), T2 (0,5 kGy), T3 (1,0 kGy) e T4 (2,0 kGy) sendo avaliados nos 3, 6, 9, 12, 15 e 20 dias após irradiação, para as seguintes análises: maturação, textura, cor, sólidos solúveis totais, pH, acidez titulável total e massa. Foram realizadas quantificações de licopeno em tomates in natura e no molho por cromatografia em coluna aberta em função do amadurecimento dos mesmos. Os resultados demonstraram que somente a massa não apresentou diferença significativa (p>0,05). Os tratamentos 1 e 2 demonstraram ser efetivos para o retardo do amadurecimento e manutenção da textura mais firme (p<0,05). Ao passo que o T4 ocasionou reações químicas na estrutura do tomate, levando-o a amadurecer precocemente em função da degradação das substâncias pécticas. A realização de um molho preparado a partir de tomates irradiados a 0.25 kGy, não apresentou diferença significativa (p>0.05) quando comparado ao controle. Entretanto, não indicou uma degradação do licopeno, como as doses de 1.0 e 2.0 kGy. Desta forma pode-se concluir que baixas doses são eficazes para manutenção do pH, firmeza, retardo da senescência, massa e ainda, além de não degradarem o principal composto bioativo do tomate: o licopeno, sugerem uma maior biodisponibilidade deste, em função da aplicação da radiação. / The purpose of the present study was to determine the effects of ionizing radiation in tomatoes (Lycopersicon esculentum Mill) and at the same time to evaluate the influence of irradiation on the content of lycopene in a sauce made with these fruits irradiated. For this reason tomatoes were subjected to five treatments: control, T1 (0.25 kGy), T2 (0.5 kGy), T3 (1.0 kGy) and T4 (2.0 kGy) and evaluated at 3, 6, 9, 12, 15 and 20 days after irradiation, for the following analysis: maturity, texture, color, soluble solids, pH, acidity and total mass. Measurements were made of lycopene in fresh tomatoes and sauce by open column chromatography according to the ripening of them. The results showed that only the mass was not significantly different (p> 0.05). Treatments 1 and 2 proved to be effective in delaying the maturation and in the maintenance of firm texture (p <0.05). While T4 caused chemical reactions in the structure of tomato, compelling it to mature earlier because of pectin degradation. The completion of a sauce made from tomatoes irradiated to 0.25 kGy, didnt show a significant difference (p> 0.05) when compared to control. However, it didnt indicate lycopene degradation, as the doses of 1.0 and 2.0 kGy. Thus we can conclude that low doses are effective for maintaining pH, firmness, delayed senescence, mass and, in addition to not degrading the major bioactive compound of tomato, lycopene, suggest a higher bioavailability of this one, depending on the radiation application.

O presente trabalho teve como objetivo estudar os efeitos da radiação ionizante em tomates (Lycopersicum esculentum Mill) e paralelamente avaliar a influência da irradiação sobre o teor de licopeno de um molho preparado com estes frutos irradiados. Para tanto os tomates foram submetidos a cinco tratamentos: controle, T1 (0,25 kGy), T2 (0,5 kGy), T3 (1,0 kGy) e T4 (2,0 kGy) sendo avaliados nos 3, 6, 9, 12, 15 e 20 dias após irradiação, para as seguintes análises: maturação, textura, cor, sólidos solúveis totais, pH, acidez titulável total e massa. Foram realizadas quantificações de licopeno em tomates in natura e no molho por cromatografia em coluna aberta em função do amadurecimento dos mesmos. Os resultados demonstraram que somente a massa não apresentou diferença significativa (p>0,05). Os tratamentos 1 e 2 demonstraram ser efetivos para o retardo do amadurecimento e manutenção da textura mais firme (p<0,05). Ao passo que o T4 ocasionou reações químicas na estrutura do tomate, levando-o a amadurecer precocemente em função da degradação das substâncias pécticas. A realização de um molho preparado a partir de tomates irradiados a 0.25 kGy, não apresentou diferença significativa (p>0.05) quando comparado ao controle. Entretanto, não indicou uma degradação do licopeno, como as doses de 1.0 e 2.0 kGy. Desta forma pode-se concluir que baixas doses são eficazes para manutenção do pH, firmeza, retardo da senescência, massa e ainda, além de não degradarem o principal composto bioativo do tomate: o licopeno, sugerem uma maior biodisponibilidade deste, em função da aplicação da radiação. / The purpose of the present study was to determine the effects of ionizing radiation in tomatoes (Lycopersicon esculentum Mill) and at the same time to evaluate the influence of irradiation on the content of lycopene in a sauce made with these fruits irradiated. For this reason tomatoes were subjected to five treatments: control, T1 (0.25 kGy), T2 (0.5 kGy), T3 (1.0 kGy) and T4 (2.0 kGy) and evaluated at 3, 6, 9, 12, 15 and 20 days after irradiation, for the following analysis: maturity, texture, color, soluble solids, pH, acidity and total mass. Measurements were made of lycopene in fresh tomatoes and sauce by open column chromatography according to the ripening of them. The results showed that only the mass was not significantly different (p> 0.05). Treatments 1 and 2 proved to be effective in delaying the maturation and in the maintenance of firm texture (p <0.05). While T4 caused chemical reactions in the structure of tomato, compelling it to mature earlier because of pectin degradation. The completion of a sauce made from tomatoes irradiated to 0.25 kGy, didnt show a significant difference (p> 0.05) when compared to control. However, it didnt indicate lycopene degradation, as the doses of 1.0 and 2.0 kGy. Thus we can conclude that low doses are effective for maintaining pH, firmness, delayed senescence, mass and, in addition to not degrading the major bioactive compound of tomato, lycopene, suggest a higher bioavailability of this one, depending on the radiation application.