Thesis (Ph.D.)--University of Adelaide, School of Agriculture and Wine, Discipline of Wine and Horticulture, 2004. / Includes bibliographical references (leaves 174-201).

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Includes bibliographical references (leaves 174-201) / xxii, 201, [20] leaves : ill., photos (col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, School of Agriculture and Wine, Discipline of Wine and Horticulture, 2004

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Submitted by (lucia.rodrigues@ufrpe.br) on 2017-02-16T13:44:43Z No. of bitstreams: 1 Adriano Marcio Freire da Silva.pdf: 233973 bytes, checksum: 8365664074820b5955fb940c37b47616 (MD5) / Made available in DSpace on 2017-02-16T13:44:43Z (GMT). No. of bitstreams: 1 Adriano Marcio Freire da Silva.pdf: 233973 bytes, checksum: 8365664074820b5955fb940c37b47616 (MD5) Previous issue date: 2005-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Lettuce (Lactuca sativa L.) and Chinese cabbage (Brassica pekinnensis L.) may present yield reduction due to the occurrence of soft rot caused by Pectobacterium carotovorum subsp. carotovorum. Surveys of the intensity of soft rot in plantations of lettuce and Chinese cabbage were performed from January to May 2004 in mesoregions of the Zona da Mata and Agreste of the state of Pernambuco, Brazil. Disease prevalence of 45.2% was observed in lettuce and 100% in Chinese cabbage. The incidence of soft rot ranged from 0 to 22% in lettuce and 1 to 67% in Chinese cabbage. In lettuce higher intensity of soft rot was observed in areas: having more than 17 years of cultivation; planted with ‘Elba’, ‘Cacheada’ and ‘Tainá’; with clay soil type; irrigated by hosing and having poor drainage. Lower disease intensity was detected in areas: planted with ‘Verdinha’ and ‘Salad Bowl’; having coriander asprevious crop and when seedlings were produced in trays. In Chinese cabbage higher intensity of soft rot was found in areas having more than 10 years of cultivation, and in plantations with more than 50 days. The sole subspecies detected causing soft rot in all areas of lettuce and Chinese cabbage was Pectobacterium carotovorum subsp. carotovorum. To determine the ideal sample size for assessing incidence of soft rot in field, pilot-samples were conducted in eight lettuce planting areas and five Chinese cabbage planting areas, located in the main production municipalities in the state of Pernambuco. Based on our data and considering 20% of acceptable error, future surveys of the soft rot incidence should analyze 32 plots/ha and 20 plants/plot with 4.5m2 for lettuce and 21 plots/ha and 20 plants/plot with 10.5m2 for Chinese cabbage. For both crops there was significant correlation (P=0.05)between the intensity of disease aggregation and sample size but not between disease incidence levels and sample sizes / Os cultivos de alface (Lactuca sativa L.) e couve-chinesa (Brassica pekinnensis L.) podem ter a produção reduzida, devido à ocorrência da podridão-mole causada por Pectobacterium carotovorum subsp. carotovorum. No período de janeiro a maio de 2004, foram realizados levantamentos da intensidade da podridão-mole em plantios de alface e couve-chinesa, nas mesorregiões da Zona da Mata e Agreste do estado de Pernambuco. A prevalência da doença foi de 45,2% em alface e de 100% em couve-chinesa, enquanto a incidência variou entre 0 a 22% na primeira cultura e 1 a 67% na segunda. Em alface, maior intensidade da podridão-mole foi constatada em áreas: com mais de 17 anos de plantio; plantadas com as cultivares Elba, Cacheada e Tainá; com solo argiloso; irrigadas pelo sistema de rega e com drenagem deficiente. Por outro lado, menor intensidade da doença foi observada emáreas: plantadas com as cultivares Verdinha e Salad Bowl; cultivadas anteriormente com coentro e onde foram plantadas mudas produzidas em bandejas. Em couve-chinesa, observou-se que a intensidade da podridão-mole foi maior em áreas: com mais de 10 anos de cultivo e em plantios com mais de 50 dias. A única subespécie encontrada causando podridão-mole em todas as áreas de cultivo de alface e couve-chinesa foi Pectobacterium carotovorum subsp. carotovorum. Para a estimativa do tamanho ideal das amostras para avaliação da incidência da podridão-mole em campo, foram conduzidas amostragens-piloto em oito áreas de plantio de alface e cinco de couve-chinesa, situadas nos principais municípios produtores do estado de Pernambuco. Considerando os resultados obtidos e um erro aceitável de 20%, emfuturos levantamentos da incidência da podridão-mole, recomenda-se a amostragemde 32 parcelas/ha e 20 plantas por parcela de 4,5m2 para a alface e de 21 parcelas/ha e 20 plantas por parcela de 10,5m2 para a couve-chinesa. Para as duas culturas, houve correlação significativa (P=0,05) entre a intensidade de agregação da doença e o tamanho da amostra, mas não entre os níveis de incidência da doença e os tamanhos das amostras

Submitted by (lucia.rodrigues@ufrpe.br) on 2017-03-17T13:11:21Z No. of bitstreams: 1 Indira del Carmen Molo Alvarado.pdf: 1069235 bytes, checksum: 54d92e63acb53f101863e46dc0721313 (MD5) / Made available in DSpace on 2017-03-17T13:11:21Z (GMT). No. of bitstreams: 1 Indira del Carmen Molo Alvarado.pdf: 1069235 bytes, checksum: 54d92e63acb53f101863e46dc0721313 (MD5) Previous issue date: 2006-07-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Yield of Chinese cabbage (Brassica pekinnensis) may be limited by the occurrence of soft rot caused by pectinolytic bacteria. In this study 39 isolates of bacteria causing soft rot in Chinese cabbage obtained from planting areas of Camocim de São Félix, in Pernambuco State, were identified and characterized as Pectobacterium carotovorum subsp. carotovorum (Pcc) based upon biochemical tests confirmed by PCR. The variability of these isolates was evaluated through disease epidemiological components, sensitivity to antibiotics and molecular markers. The isolates were distributed in similarity groups considering 50% of the total linkage distance by the UPGMA method. Based on epidemiological components incubation period (PI), initial severity (SEVI), final severity (SEVF) and area under the disease curve progress the 39 isolates were distributed in six similarity groups. Among the epidemiological components significant Piersoncorrelation (P≤0.05) was only found for PI and SEVI (r = -0.57). Based on sensitivity to 12 antibiotics, the Pcc were distributed in 14 groups. There were significant correlations between sensitivity to gentamicin and PI (r = -0.41), as well as between sensitivity to clindamicin and SEVF (r = -0.45). The molecular markers REP, ERIC and BOX used in Rep-PCR revealed high genetic variability among the 39 isolates since 32 similarity groups were formed. No significant correlations were found among the linkage distances registered by molecular markers and the disease epidemiological components. In a second study it was evaluated soil influence on Pcc rifampicin resistant mutant (Pcc127Rif). The extinction rate of population was calculated (TEP) and ranged from 0.0547 to 0.6327 log (CFU)/d. Six soils showed suppressiveness to Pcc127Rif while five presented conducivity. The soil groupsbased on the TEP of Pcc127Rif did not correlate with municipalities, types of vegetation cover at the sampling time or soil textural classes. Considering all soils there were no significant correlations (P≤0,05) among TEP of Pcc127Rif and chemical, physical and microbiological characteristics of soils. Considering the six more suppressive soils the TEP of Pcc127Rif significantly correlated with soil apparent density (r = 0.76), total bacterium population (r = 0.82) and Bacillus spp. (r = 0.80). The Bacillus spp. population correlated with apparent density, but not with total bacterium population. Considering the five more conducive soils there was correlation between TEP of Pcc127Rif and Bacillus spp. population (r = -0.86). The high variability among Pcc isolates points out to the necessity of great attention in studies covering identification, detection, epidemiology and control of soft rot in Pernambuco. The elevated correlation between suppressiveness of some soils to P. carotovorum subsp. carotovorum and total bacteria and Bacillus spp. populations is relevant to effective implementation of soft rot management strategies / A produção de couve-chinesa (Brassica pekinensis) pode ser limitada pela ocorrência da podridão-mole causada por bactérias pectinolíticas. No presente estudo, 39 isolados de bactérias causadoras de podridão-mole em couve-chinesa, oriundos de áreas de plantio de Camocim de São Félix, em Pernambuco, foram identificados e caracterizados como Pectobacterium carotovorum subsp. carotovorum (Pcc) por testes bioquímicos confirmados por PCR. A variabilidade desses isolados foi avaliada com base em componentes epidemiológicos da doença, sensibilidade a antibióticos e marcadores moleculares. Os isolados foram distribuídos em grupos de similaridade, considerando-se 50% da distância total de ligação pelo método UPGMA. Com base nos componentes epidemiológicos período de incubação (PI), severidade inicial (SEVI), severidade final (SEVF) eárea abaixo da curva de progresso da doença, os 39 isolados foram distribuídos em seis grupos de similaridade. Entre os componentes epidemiológicos, foi constatada correlação significativa (P≤0,05) somente de PI com SEVI (r = -0,57). Baseado na sensibilidade aos 12 antibióticos, os isolados de Pcc foram distribuídos em 14 grupos. Foram constatadas correlações significativas entre sensibilidade a gentamicina e PI (r = -0,41), bem como entre sensibilidade a clindamicina e SEVF (r = -0,45). A utilização dos marcadores moleculares REP, ERIC e BOX no Rep-PCR revelou grande variabilidade genética entre os 39 isolados, pois foram formados 32 grupos de similaridade. Não foram constatadas correlações significativas entre as distâncias de ligação registradas pelos marcadoresmoleculares e os componentes epidemiológicos da doença. Em outro estudo foi avaliada a influência dos solos na população de Pcc, utilizando-se mutanteresistente a rifampicina (Pcc127Rif). A taxa de extinção relativa da população (TEP) variou de 0,0547 a 0,6327 log (UFC)/dia. Seis solos mostraram-se supressivos a Pcc127Rif enquanto cinco evidenciaram conducividade. Os grupos de solos baseados na TEP de Pcc127Rif não apresentaram relação com os municípios de coleta, tipos de coberturas do solo na época da coleta ou classes texturais dos solos. Considerando-se todos os solos, não foram constatadas correlações significativas (P≤0,05) entre a TEP de Pcc127Rif e as características químicas, físicas e microbiológicas dos solos. Nos seis solos mais supressivos, a TEP de Pcc127Rif se correlacionou significativamente com a densidade aparente do solo (r = 0,76), populações de bactérias totais (r = 0,82) e Bacillus spp. (r = 0,80). A população de Bacillus spp. se correlacionou com a densidade aparente, mas não com a população de bactérias totais. Nos cinco solos mais conducivos houve correlação entre a TEP de Pcc127Rif e a população de Bacillus spp. (r = -0,86). A elevada variabilidadeverificada entre os isolados de Pcc aponta para a necessidade de maior atenção em estudos de identificação, detecção, epidemiologia e controle da podridão-mole em Pernambuco. A alta correlação observada entre a supressividade de alguns solos a Pcc e as populações de bactérias totais e Bacillus spp. é relevante para implementação efetiva de estratégias de manejo da doença.

This research was conducted in order to evaluate natural trace element (TE) contents and anthropogenic contamination in soils and vegetables in Chenggong County (Yunnan Province, China). In this way, trace element contents in soils have been analysed to assess TE contamination in soils and vegetables, and transfer of TE from soil to vegetables. Agricultural practises have been proposed to amend the quality of vegetables. We identified three geomorphopedological units: lacustrine unit, transition unit and mountain unit.  In the mountain unit, soil texture is clay more often from the weathering of limestone and marlstone. Soil colour is red or reddish brown with acid reaction.  In the transition unit, soil texture is loamy clay. Soil colour is red-brown with acid reaction.  In the lacustrine unit, soil texture mainly is sandy developed from lacustrine-alluvial deposits. Soil colour is brown and is slightly acid. Total TE contents in the topsoil are higher than usual and even Kunming Prefecture soil. TE contents indicate a high contaminated level when considered globally. Pb, Cd and Zn present however individually low contaminated levels, and Cu presents a medium contaminated level. TE contents decrease from northeast to southwest, which is consistent with the elevation gradient. Significant differences of TE contents are observed according to distance from Chenggong town in the lacustrine unit and with distance from the mountain in the transition unit. TE accumulation is usually observed along roads. TE contents in subsoil are related to soil colour, texture, parent materials and mottles. Accumulation of Pb and Zn in topsoil and of Cu and Cd in subsoil are observed. The highest contents are observed for Pb in cauliflower, Cd in lettuce and Chinese cabbage, and Cu and Zn in pea. The order of TE accumulation in plants varies according to the plant species and organ. According to relations between TE contents in Chinese cabbage and extraction sequential fractions of TE in soils, different soil fractions are suggested as soil assessment indicators. Lime and pig manure have been applied to modify the soil pH and to decrease the mobility of TE in situ. With increasing in lime rate and pH, contents of acetic-acid extractable TE fractions in soil decrease. Enrichment coefficients related to TE availability (AEC) of Pb and Cu are stable and are not changed by lime or pig manure. AEC of Cd and Zn which are high in low pH, decrease with increased pH and application rates of lime and pig manure. When application rates of lime and pig manure increase, TE contents in Chinese cabbage decrease and biomass of Chinese cabbage increases. Application rates of lime and pig manure are recommended, but their quality should also be taken into account. / Cette recherche a pour objet l'étude de la teneur naturelle en éléments traces métalliques (ET) et de la contamination anthropique des sols et des productions légumières dans le Comté de Chenggong (Province du Yunnan, RP de Chine). Pour cela, la variabilité des teneurs en fonction des conditions géomorphopédologiques a été analysée, ainsi que les transferts des ET du sol vers les végétaux. Cette approche a permis ensuite d'aborder l'évaluation de la qualité des sols et des légumes, puis de proposer des pratiques agricoles alternatives dans le but d'améliorer la qualité des légumes produits. La zone d'étude a été divisée en 3 unités géomorphopédologiques: unité de montagne où les sols brun rouge à rouge résultent notamment de l'altération de calcaires et de marnes. Une texture argileuse et une réaction acide dominent. unité de piedmont (dite de transition) où les sols de couleur jaune clair à jaune rougeâtre résultent principalement de l'altération de grès et de shales. Une texture limono-argileuse en surface et argileuse en profondeur, ainsi quune réaction acide dominent. unité lacustre, à proximité du Dianchi Lake, dont les sols de couleur brun foncé sont essentiellement développés à partir de sédiments lacustres. Une texture sableuse domine en surface, ainsi qu'une réaction faiblement acide à neutre. Les teneurs en ET rencontrées en surface des sols de la zone d'étude sont plus élevées que les teneurs moyennes observées dans les sols du monde ou même de la préfecture de Kunming. Evaluées séparément pour chaque ET, les teneurs rencontrées correspondent à des niveaux de contamination jugés faibles pour Pb, Cd et Zn, moyen pour Cu. Considérées simultanément, ces teneurs permettent de déterminer un indice de contamination global correspondant à un niveau de contamination élevé. Les teneurs en ET décroissent globalement du nord-est vers le sud-ouest, suivant le gradient d'altitude. Ces teneurs varient également de façon significative en fonction de l'éloignement de la montagne dans l'unité de transition et de l'éloignement de l'agglomération de Chenggong dans l'unité lacustre . Une accumulation en ET est souvent observée le long des routes. Dans le sous-sol, les teneurs en ET sont liées à la couleur, à la texture, au matériau parental, et aux marques d'altération. Les teneurs sont plus élevées en surface pour Pb et Zn, et en profondeur pour Cu et Cd. Les teneurs les plus élevées pour Pb sont observées dans le chou-fleur, pour Cd dans la laitue et le chou chinois, pour Cu et Zn dans le pois.L'ordre d'accumulation des ET dans la plante dépend de l'espèce et de l'organe considérés. En fonction des corrélations observées entre les teneurs du chou chinois et les résultats obtenus avec différentes modalités d'extraction des ET du sol, des indicateurs d'évaluation de la qualité du sol ont été proposés. Un amendement carbonaté et du fumier de porc ont été épandus afin de réduire in situ la mobilité des ET. L'augmentation de l'apport d'amendement carbonaté permet d'augmenter le pH du sol et de diminuer la fraction extraite avec l'acide acétique dilué (AA) pour chaque élément. Les AEC, rapports teneur dans la plante : teneur dans le sol extractible à lAA, sont stables pour Pb et Cu et ne sont modifiés par aucun des 2 apports. Cependant, les AEC de Zn et de Cu, élevés quand le pH du sol est acide, diminuent si le pH devient plus alcalin, ainsi qu'avec les apports d'amendement carbonaté et de fumier de porc. Quand les apports d'amendement carbonaté et de fumier de porc augmentent, les teneurs en ET du chou chinois diminuent et sa biomasse augmente. Un épandage d'amendement carbonaté est donc recommandé. Cependant la plus grande attention doit être portée à la qualité des fumiers de porcs dont les teneurs en Zn et Cu ne sont pas négligeables.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The Chinese cabbage is a vegetable largely cultivated by organic farmers in the region of Santa Maria, RS. However, due to severe damage caused by the chrysomelid Microtheca ochroloma Stal, many of them are abandoning the crop. The use of botanical pesticides is an alternative for the control of these insect pests. Therefore, this study aimed to evaluate the action of commercial products and aqueous extracts of insecticide plants on the different stages of development, food consumption and biological aspects of M. ochroloma. In experiments conducted in laboratory, at a temperature of 25 ± 2ºC, relative humidity of 60 ± 10% and 14 hours of photophase, the effects of aqueous extracts of 10% w/v of Nicotiana tabacum L. (in the form of tobacco-powder), of leaves of Melia azedarach L., Eucalyptus citriodora Hook, Cedrella fissilis L., Trichilia claussenii C. DC., Blepharocalyx salicifolius (Kunth) O. Berg, Eugenia uniflora L., Cinnamomum camphora (L.) J. Presl, Syzygium cuminii L., Cymbopogon nardus (L.) Rendle, of leaves and twings of Ateleia glazioveana Baill, Senecio brasiliensis Less and Ruta graveolens L., of seeds of Azadirachta indica A. Juss, and the commercial products Organic Neem ®, 1 and 5% v / v, and Neem Azal T / S ®, 0.5 and 1% v / v, both elaborated from A. indica (neem) were assessed. The action of the treatments was tested on eggs up to 24 hours old; under direct contact and ingestion of three-day-old larvae, in which were assessed the viability of larvae and pupae, the larval period and the defective adults; and in adults with unknown age also under the action of contact and ingestion. In addition, leaf discs of Chinese cabbage were treated with different treatments and with distilled water (control) and offered to larvae and adults in free-choice and no-choice tests. The commercial products Neem Azal T / S and Organic Neem and the extracts of M. azedarach, of tobacco powder, of S. brasiliensis and of B. salicifolius, by causing mortality at different stages of development of M. ocrholoma and decrease in the consumption of treated leaves, and also the extract of E. uniflora due to its action in the biology of these insects, should be evaluated in field conditions as potential alternatives to be used for the control of M. ochroloma. / A couve-chinesa é uma hortaliça bastante cultivada por produtores orgânicos da região de Santa Maria, RS. Porém, devido a danos intensos causados pelo crisomelídeo Microtheca ochroloma Stal, muitos estão abandonando a cultura. A utilização de inseticidas botânicos é uma alternativa para o controle desses insetos-praga. O presente trabalho teve, portanto, o objetivo de avaliar a ação de produtos comerciais e de extratos aquosos à base de plantas inseticidas sobre as fases de desenvolvimento, o consumo alimentar e aspectos da biologia de M. ochroloma. Em experimentos realizados em laboratório, à temperatura de 25 ± 2ºC, umidade relativa de 60 ± 10% e fotofase de 14 horas, foram avaliados os efeitos dos extratos aquosos, a 10% p/v, de Nicotiana tabacum L. (sob a forma de pó-de-fumo), de folhas de Melia azedarach L., Eucalyptus citriodora Hook, Cedrella fissilis L., Trichilia claussenii C. DC., Blepharocalyx salicifolius (Kunth) O. Berg, Eugenia uniflora L., Cinnamomum camphora (L.) J.Presl, Syzygium cuminii L. Cymbopogon nardus (L.) Rendle, de folhas e de ramos de Ateleia glazioveana Baill, Senecio brasiliensis Less e Ruta graveolens L., de semente de Azadirachta indica A. Juss, além dos produtos comerciais Organic Neem®, a 1 e 5% v/v, e NeemAzal T/S®, a 0,5 e 1% v/v, ambos à base A. indica (nim). Foi testada a ação dos tratamentos sobre ovos; sob ação de contato e de ingestão em larvas com idade de três dias, nas quais foram avaliados a viabilidade larval e pupal, a duração da fase larval e os adultos defeituosos; e, também sob ação de contato e de ingestão, em adultos com idade desconhecida. Ainda, discos de folhas de couve-chinesa foram tratados com os diferentes tratamentos e com água destilada (testemunha) e oferecidos para larvas e adultos em testes com e sem chance de escolha. Os produtos comerciais NeemAzal T/S e Organic Neem e os extratos de M. azedarach, de pó-de-fumo, de S. brasiliensis e de B. salicifolius, por causarem mortalidade a diferentes fases de desenvolvimento de M. ochroloma e diminuição do consumo de folhas tratadas, e, ainda, o extrato de E. uniflora, pela ação na biologia desses insetos, devem ser avaliados, em condições de campo, como sendo alternativas potenciais a serem utilizadas visando o controle de M. ochroloma.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The Chinese cabbage (Brassica chinensis L.) has been indicated, along with other vegetables, as an excellent alternative for Brazilian agribusiness, especially those grown in organic production system. Regarding to insect pests, that damage this crop, it shows the chrysomelid Microtheca semilaevis Stal, which cause defoliation on plants during larval and adult stages. Thus, the present work was developed to study bioecology aspects of M. semilaevis, obtaining information about biology, food preference and consumption, natural enemies and population fluctuation. In laboratory and under controlled conditions, biological aspects, such as duration, feasibility and measurement of the immature and adults; and fertility and longevity of adults were evaluated to determine fertility life table. Also in laboratory, experiments to evaluate food consumption and feeding preference of these beetles were conducted fed on leaf discs of four host varieties: Chinese cabbage, watercress (Nasturtium officinale L.), arugula (Eruca sativa L.) and mustard (Brassica juncea C.). Under field conditions, samples of natural enemies of the different development stages were taken in cultivation, besides studying the population dynamics of Microtheca spp. during Chinese cabbage crop cycle in Santa Maria, RS. The eggs have an average incubation period of 6.13 ± 0.04 days and average survival rate of 76.00%. M. semilaevis presents four larval instars, and the average duration of each instar were 2.86 ± 0.06, 1.97 ± 0.05, 1.80 ± 0.06 and 2.43 ± 0.07 days. The cycle from egg to adult is approximately 22 days. Life table fertility determined an increasing capacity of 166 times in each generation, and the average length of a generation of 49 days and finite rate of increase of 1.116 individuals / week. Larvae prefer watercress among crucifers tested, while adults prefer watercress and arugula, with lower consumption for both development stages ranging from Chinese cabbage and mustard. The peak population of larvae and adults in the field occurred in October. There was no emergence of parasitoids on larval and adult stages. However, predators were found belonging to four families with a predominance of Coccinellidae and Pentatomidae and also Vespidae and Reduviidae were found in smaller numbers. The results in this work provide subsidies that might be used for the establishment of integrated management strategies for M. semilaevis. / A couve-chinesa (Brassica chinensis L.) tem sido apontada, juntamente com outras hortaliças, como uma excelente alternativa para o agronegócio brasileiro, em especial aquelas cultivadas no modo de produção orgânica. Com relação aos insetos-praga que danificam a cultura, destaca-se o crisomelídeo Microtheca semilaevis Stal, causando desfolhamento nas plantas durante as fases larvais e adulta. Assim, o presente trabalho teve como objetivo estudar aspectos bioecologicos de M. semilaevis, obtendo informações sobre biologia, preferência e consumo alimentar, inimigos naturais e flutuação populacional. Em laboratório e sob condições controladas, foram avaliados aspectos biológicos, como a duração, a viabilidade e a medição de imaturos e adultos; também, a fecundidade e a longevidade dos adultos, para permitir a elaboração da tabela de vida de fertilidade. Ainda em laboratório, experimentos avaliaram o consumo e a preferência alimentar desses coleópteros alimentados com discos foliares de quatro variedades hospedeiras: couvechinesa, agrião (Nasturtium officinale L.), rúcula (Eruca sativa L.) e mostarda (Brassica juncea C.). Em condições de campo, foram realizadas coletas em cultivo dos inimigos naturais das diferentes fases de desenvolvimento, além de estudar a flutuação populacional de Microtheca spp. no ciclo da cultura de couve-chinesa em Santa Maria, RS. Os ovos apresentam um período de incubação médio de 6,13±0,04 dias e viabilidade média de 76,00%. M. semilaevis apresenta a fase larval com quatro instares, sendo que a duração média de cada ínstar foi de 2,86±0,06; 1,97±0,05; 1,80±0,06 e 2,43±0,07 dias. O ciclo de ovo a adulto foi de, aproximadamente, 22 dias. Através da tabela de vida de fertilidade determinou-se uma capacidade de aumento de 166 vezes a cada geração, sendo a duração média de uma geração de 49 dias e a razão finita de aumento de 1,116 indivíduos/semana. Larvas preferem agrião dentre as brássicas testadas, sendo que adultos preferem agrião e rúcula, com menor consumo, para ambas as fases de desenvolvimento, variando entre couve-chinesa e mostarda. Os picos populacionais de larvas e adultos, no campo, ocorreram no mês de outubro. Não houve emergência de parasitoides nas fases larval e adulta. Porém, foram encontrados predadores pertencentes a quatro famílias com predomínio de Coccinellidae e Pentatomidae, sendo Vespidae e Reduviidae presentes em menor número. Os resultados encontrados no presente trabalho fornecem subsídios que podem ser utilizados para o estabelecimento de estratégias de manejo integrado de M. semilaevis.

MSCAGR (Plant Production) / Department of Plant Production / Poor soil fertility caused by inadequate supply of nutrients on soil is one of the major constraints limiting crop production especially in the Vhembe District Municipality, Limpopo, South Africa. Therefore, management practices such as application of organic manure to minimize soil infertility is considered as good practice for smallholder farmers. This study aimed at evaluating the effect of macadamia husk compost on selected soil properties as well as the growth and yield of Chinese cabbage on sandy loam soil. A field experiment was carried out during 2018 and 2019 winter season at the Agricultural Research Council (ARC) research farm in Levubu. The experiment was laid out in a randomized complete block design (RCBD) with 4 treatments (control (zero)), inorganic fertilizer (100:60:60 NPK Kg ha-1) and compost at 15t ha-1 & 30t ha-1 replicated 3 times. Soil was analyzed before planting and after harvesting to determine the influence of applied compost on selected physical properties (soil bulk density and water holding capacity) and chemical properties (soil pH, soil organic matter, soil organic C, EC, total N, P, K, Ca, Mg, Na, Al, Zn and Mn). Number of leaves, fresh mass, dry mass and leaf area was collected at three harvests interval (28, 46 and 74 days after transplanting). After each harvest period, leaves were analysed for nutrient content (N, P, K, Ca, Mg, Zn, Cu, Mn and B). During the final harvest crops were uprooted and root biomass (fresh mass, dry mass and root length) were recorded. Analysis of variance (ANOVA) were conducted on all data using Genstat package 18th addition. Differences between treatment means were separated using the least significant differences (LSD) procedure and correlations analysis was determined using Pearson’s simple correlation coefficient. Macadamia husk compost application had a significant effect on soil bulk density and water holding capacity. Addition of macadamia husk compost significantly increased soil pH, OC, N, C: N K, P, Mg, Ca, Na, Al, Zn, Ca and Mn. In contrast, addition of macadamia husk compost had no effect on soil EC. Yield components (number of leaves, fresh mass, dry mass), root biomass, root length and leaf area increased with application of macadamia husk compost. Yield components, root biomass, root length and leaf area were significantly affected (p<0.01) by harvesting time. Yield components in the second cropping season was greater than yield components in the first season. Macadamia husk compost application showed no significant effect on leaf nutrient content of Chinese cabbage. However, leaf nutrient content was affected by harvesting time. It is evident from the results of this study that macadamia husk compost affects soil fertility and plant production. The results suggest that macadamia husk compost has a potential to be used as a reliable fertilizer by famers especially smallholder farmers who struggle to buy inorganic fertilizer because they are expensive. Since this study was conducted over two seasons and compost effect tend to be long term, further research is needed on application of macadamia husk compost on soil properties and yield of other crops over wide range of soils. / NRF