Chlorophyll and solanine syntheses as influenced by cultivars, specific gravities, light intensities, and duration of exposure to light were studied in potato (Solanum tuberosum, L.) tubers. Chemicals, gamma radiation, clear polyethylene packaging in 15 per cent co 2 , and storage at subatmospheric pressure were employed to control the formation of these two compounds. The toxicity of solanine to mice, the fungus Trichoderma viride, and cholinesterase inhibition patterns in rabbits and a dog were evaluated. The influence of the central nervous system stimulating drugs was investigated to find if they counteracted solanine toxicity. Of the 11 cultivars tested, tubers of Bounty, Kennebec, Nor chip, and Red Lasoda were most sensitive to greening and solanine development. LaChipper and Platte tubers were least susceptible to greening and their solanine contents were minimum. The significant differences in chlorophyll and solanine formation among cultivars showed that greening potential is a cultivar characteristic. xi Chlorophyll development in tubers was inversely related to their specific gravity. Solanine synthesis was, however, not dependent on specific gravity. Studies on effect of four light intensities on Kennebec potato tubers that were stored for nearly 6 months showed that more chlorophyll formed at 100 and 150 ft-c than at 50 and 200 ft-c light intensities. Generally, chlorophyll formation increased with increased light intensity up to 100 ft-c, slowly and steadily declined up to 150 ft-c, and sharply declined at 200 ft-c. There were no significant differences in the solanine contents of the tubers after exposure to these light intensities. The duration of exposure of the tubers to 100 ft-c revealed that solanine and chlorophyll contents increased linearly with the duration of exposure up to the sixth and tenth day, respectively. There was no difference in the amount of chlorophyll formed at the end of the tenth and fifteenth day. The solanine contents were rather constant from the sixth to the tenth day and then slightly declined at the end of the fifteenth day. The respiration of the tubers did not seem to have an apparent relationship to solanine and chlorophyll formation. Investigation on the control of greening showed that two chemicals, Ethrel (2-chloroethylphosphonic acid) and Alar (succinamic acid, 2, 2-dimethylhydrazide) when applied at 10, 000 ppm by vacuum injection technique, were significantly effective in inhibiting chlorophyll and solanine syntheses. Ethrel was most effective in controlling the chlorophyll formation and the least solanine xii was formed after the Alar treatment. The dose of 10 krads of gamma radiation inhibited 80 per cent, while polyethylene packaging with 15 per cent co 2 , only 32 per cent of chlorophyll synthesis. Storage of tubers at subatmospheric pressure of 126 mm-Hg resulted in complete inhibition of chlorophyll formation. The irradiation, co 2 environment either alone or in combination, and subatmospheric pressure treatments did not affect solanine synthesis. Solanine was toxic to mice, rabbits, a dog, and the fungus Trichoderma viride. The LD 50 for intraperitoneal (ip) administration, single dose, in mice was 32. 3 mg of solanine per Kg body weight, the 19/20 confidence limits being 27. 6 - 37. 9 mg. Plasma and erythrocytic cholinesterase inhibition in rabbits indicated that solanine was a weak to moderate inhibitor of both specific and nonspecific cholinesterase. There was less inhibition of erythrocytic cholinesterase than that of plasma in vivo. In an anesthetized dog, cumulative doses of solanine showed a quick inhibition of cholinesterase but rapid recovery · was noted in the case of serum enzyme, while there was no inhibition of the red cell enzyme. A prior intraperitoneal dose of 2 mg/Kg of atropine sulfate lowered the mortality after ip injection into mice at 40 mg/Kg of solanine from 9/10 to 5/10. Similar application of pargyline (5 mg/Kg ip) and amphetamine (5 mg/Kg ip) had no effect on mortality from solanine. Atropine influence appeared antagonistic and counteracted solanine toxicity. The concentration of 10 mg of solanine per 100 ml of potato-dextroseagar medium had no effect on the Trichoderma viride fungus growth, while at a concentration of 200 mg, the growth ceased. The (Lethal Concentration) Lc 50 was 102. 2 mg/100 ml, and 19/20 confidence limits being 83. 85 - 124. 6 mg.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 3 uppsatser.

Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniversitet, 2004. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2005. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2010. / Härtill 3 uppsatser.

Made available in DSpace on 2014-06-11T19:28:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-03-04Bitstream added on 2014-06-13T19:37:28Z : No. of bitstreams: 1 scudeler_f_me_botfca.pdf: 1044258 bytes, checksum: 463181dbc507a5ef09e2efc81b815e2a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Empresa Privada / A cultura da batata possui grande expressão econômica dentro do cenário agrícola. Para issso, equipamentos e técnicas de aplicação de produtos fitossanitários vêm sendo desenvolvidos visando melhorar o rendimento econômico da cultura. Neste sentido, experimentos foram conduzidos na cultura da batata (cv Àgata) objetivando avaliar a deposição da pulverização e ângulos por meio de um traçador cúprico, bem como as perdas da calda para o solo. Utilizou-se o pulverizador Advance Votrtex 2000 com presença e ausência de ar junto a barra de pulverização e ângulos de aplicação de +30 graus, O graus e -30 graus (sinal + a favor e -contrário ao deslocamento) totalizando seis tratamentos. As diferentes combinações envolvendo assistência de ar e ângulo da barra foram analizadas por meio da aplicação de 400 L ha-1 de calda utilizando pontas de jato Cônico vazio JA-4 a 633 kPa de pressão. Para avaliacção dos depósitos do ion cobre foi desenvolvido um instrumento metálico de amostragem simultânea das superfícies adaxial e abaxial dos folíolos. Os depósitos foram removidos por água de lavagem e quantificados por espectrofotometria de absorção atômica, em ambas as superficies foliares, nas posições superior e inferior das plantas de batata. As perdas da pulverização foram avaliadas em coletores plásticos colocados nas entrelinhas das percelas experimentais. Os níveos dos depósitos do traçador cúprico nas difrentes posições da planta foram analisados pelo teste estatístico T2 de Hotteling. Os maiores depósitos foram constatados cm a barra pulverizadora posicionada a 0 graus e +30 graus , em presença da assintencia de ar, tanto na posição superior quanto na inferior da planta. A presença do ar , além de propiciar maiores depósitos na parte inferior da plantas possibilitou maior uniformidade na distribuição dos depósitos. As perdas da pulverização para o solo ficaram abaixo de 4%. / Within the Brazilian agricultural scene, the potato crop plays a significant economic role. Modern equipment and the development of improved chemical product application techniques contribute to the constant search for a improved revenue from de potato crop. Experiments were carried out on a potato crop of the Agata variety. The aim was to evaluate spray deposition whit a cupric tracer using air assistance and also the spray loss on the soil. An Advance Vortex 2000 sprayer was used both with and without boom air assistance at different angles of application. The boom angles at 0°, +30° and -30° were directioned in a vertical position as well as forwards and back forwards in accordance with displacement. Six combinations treatments were used in a experiment. The trials were sprayed at 400 L ha-1 volume rate using hollow cone nozzles JA-4 at 633 kPa. An instrument, which simultaneously took samples of both the underside and upperside of leaflets, was developed in order to evaluate the tracer deposits. The deposits on both surfaces at upper and lower leaflet were removed by washing with water and quantified by spectrophotometry of atomic absorption. To measure spray loss, plastic measuring collectors were placed between rows. The cupper tracer deposit levels in different positions of the plant were analysed by Tø Hotteling statistic test. Larger deposits were detected in both upper and lower plant positions 4 when the spray boom was positioned at 0º and +30º with the presence of air assistance. The presence of air, as well as having the effect of increasing spray deposits in the lower regions of the plant, helped bring about greater uniformity in the distribution of it. The spray loss was bellow 4%.

Orientador: Rogério Peres Soratto / Resumo: Dentre os nutrientes que mais limitam a produtividade da cultura da batata (Solanum tuberosum L.) está o fósforo (P). Esta cultura tem respondido à adubação fosfatada com incrementos na produtividade até altas doses, principalmente em solos com baixo teor de P disponível, que é uma característica dos solos tropicais brasileiros, os quais são naturalmente deficientes em P. A fim de melhorar a eficiência de aplicação do adubo fosfatado, é possível utilizar fertilizantes contendo substâncias húmicas (SH) ou aplicá-las diretamente no solo. No entanto, o efeito da aplicação de SH pode depender dentre outros fatores, da textura do solo, que interfere na retenção do P. Portanto, o objetivo do presente estudo foi avaliar o efeito da aplicação de SH e doses de fertilizante fosfatado sobre a nutrição, acúmulo de matéria seca (MS), crescimento radicular, absorção e exportação de nutrientes e produtividade de tubérculos da cultura da batata, em solos de diferentes texturas. Esta pesquisa foi desenvolvida através da condução de quatro experimentos, dois em casa de vegetação e dois em campo. Dois dos experimentos foram realizados em solo de textura arenosa (um de casa de vegetação e um de campo) e os dois demais em solo de textura argilosa. Em todos os experimentos, o delineamento experimental utilizado foi em blocos ao acaso, no esquema fatorial 4 x 3. Os tratamentos consistiram de quatro doses de P (10, 50, 100 e 200 mg dm-3 de P nos experimentos de casa de vegetação; 0, 100, 200 e 40... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor