Vegetative rescue of Cedrela fissilis Vell. by the rooting of cuttings from epicormic and canopy sprouts / Resgate vegetativo de Cedrela fissilis Vell. por enraizamento de estacas de brotos epicórmicos e de copa

ABSTRACT: Cedrela fissilis is a species of great genetic diversity, with low population density and seminal propagation, which causes difficulties in the vegetative propagation process. This research evaluated the vegetative rescue and propagation of stem cutting rooting originated from epicormic and canopy sprouts of C. fissilis. For this, the induction of epicormic sprouts was evaluated 52 days after the complete girdling and semi-girdling 20 and 40 cm from the ground, and no girdling treatment, during spring (2018), summer (2018) and autumn (2019). The variables evaluated were, survival (%), sprouting (%), number, length (cm) and diameter (mm) of sprouts. The cuttings were made from spring epicormic sprouts, divided in two categories: 10 cm cuttings placed vertically in pits and 5 cm cuttings placed horizontally in furrows. The canopy sprouts were collected in the summer, then cut in apical and intermediate cuttings (15 cm). After 60 days, the cuttings were evaluated in survival (%), rooting (%), callus (%), average number and length of roots (cm). Results showed that only the complete girdling produced sprouts (average >67%) with no difference between 20 and 40 cm heights, with a greater number of sprouts during spring. The cuttings from epicormic sprouts, planted vertically in pits presented higher percentage of rooting (44%) than cuttings planted horizontally in furrows (17%). Cuttings from the canopy had inconsiderable rooting (apical - 2%; intermediate - 0%). The girdling periods influences the number of epicormic sprouts and its use for cutting was more efficient in rooting.

RESUMO: Cedrela fissilis é uma espécie de grande diversidade genética, com baixa densidade populacional florestal, de propagação seminal, que apresenta dificuldade de ser propagada vegetativamente. O objetivo deste trabalho foi avaliar o regate e propagação vegetativa a partir do enraizamento de estacas de origem epicórmicas e de copa de C. fissilis. Para isso, a brotação epicórmica foi avaliada 52 dias após o anelamento completo e semianelamento nas alturas de 20 e 40 cm, e tratamento sem anelamento, durante primavera (2018), verão (2018) e outono (2019). Foram avaliados: sobrevivência das árvores (%), brotação (%), número, comprimento (cm) e diâmetro (mm) de brotos. A estaquia utilizou brotos epicórmicos de primavera, divididos em duas categorias: estacas com 10 cm colocadas verticalmente em covas e estacas de 5 cm colocadas horizontalmente em sulcos. Brotos de copa foram coletados no verão, cortados em estacas apicais e intermediárias (15 cm). Após 60 dias avaliou-se das estacas: sobrevivência (%), enraizamento (%), calos (%), número médio e comprimento de raízes (cm). Os resultados apresentam que apenas o anelamento completo formou brotos (média >67%), sem diferença entre a altura 20 e 40 cm, com maior número de brotos durante a primavera. As estacas de brotos epicórmicos, plantadas verticalmente em covas, apresentaram a maior porcentagem de enraizamento (44%) que estacas plantadas horizontalmente em sulcos (17%). Estacas de copa obtiveram enraizamento desconsiderável (apicais - 2%; intermediárias - 0%). As épocas de anelamento influenciam no número de brotos epicórmicos e seu uso como estacas foi mais eficiente no enraizamento.

Feasibility in seed germination of Hypericum perforatum L. submitted at different temperatures and treatments with high dilutions

Background Hypericum perforatum is used as a medicinal plant, mostly in antidepressant treatment. With endogenous and exogenous dormancy, more studies about the germination of the seeds are necessary. Aim: To evaluate the effect of temperature and of preparations of high dilutions on the germination of seeds of Hypericum perforatum. Methods Three bioassays were carried out in chambers of germination, using a completely randomized experimental design and in duplicate. In the first bioassay, of temperatures of 20, 25 and 30 ºC was evaluated, with 20 replicates and 50 seeds in each replicate. In the second, the effect of high dilutions (Kali carbonicum, Natrum muriaticum, Phosphorus and Silicea terra in 12cH) using 4 replicates with 50 seeds each. In the third, Kali carbonicum was tested at 6, 12, 20, 30 cH with 50 seeds and 4 replicates. The percentage of germination, germination rate index (GRI), average germination time (AGT) and seedlings with cotyledons. The data were analyzed through the R software at a 5% significance. Results At the temperature of 25 °C, 63% of the seeds germinated while at the temperatures of 20 and 30 °C the percentage was 26% and 18%, respectively. In seeds treated with Kali carbonicum 12cH the germination rate increased significantly in relation to the control group. Kali carbonicum 6cH increased the GRI of the seeds, while at 20cH, it increased the AGT, showing delay in germination. Conclusion The use of the Kali carbonicum assists in the breakage of dormancy and average time of germination in Hypericum perforatum seeds. (AU)

Potato genotypes reaction to early blight and late blight in organic cultivation / Reação de genótipos de batata à pinta preta e requeima em cultivo orgânico

ABSTRACT: Disease management in conventional potato crops requires the use of larger amounts of phytosanitary products and increased toxicity with regard to organic cultivation which may pose a risk to human health and have a negative impact on the environment as well. The present study aimed to evaluate the yield and the reaction of potato genotypes to both late blight and to early blight under an organic system of cultivation. Eperiments were conducted in the field in the municipalities of Lages, SC and Quilombo, SC, south Brazil, during the crops of 2012/2013 and 2013/2014. The experimental design consisted of a randomized complete block design with 4 replications; The following eight local clones from the Santa Catarina mountain range (serra) were evaluated: SJ01273-1; SJ01251-1; SJ01213-1; SMSJ07344-54; SJ04510-1; SJ05621-11; SJ02411-5; and SJ04521-3; and 8 commercial cultivars were assessed as follows: Agate, Asterix, and Monalisa of Dutch origin; Panda of German origin; and BRS Ana, BRS Eliza, Cota, and Catucha of Brazilian origin. Incidence and severity of late blight and early bright and the weight and number of tubers produced were evaluated. Potato genotypes showed variability in terms of tuber production and disease resistance. The regional clone 15 and cultivars BRS Ana and Cota presented resistance to early blight and to late blight in both cultivated sites. Genotype 35 and cvs. Asterix and BRS Ana were the ones that had the largest productions. Genotype 35 was the most productive one among all genotypes/clones evaluated (16,926.81kg ha-1). There was variability between different local potato genotypes in terms of productivity potential and resistance to diseases under the organic system of cultivation. These findings showed that there is a source of resistance to genetic improvement programs.

RESUMO: O manejo de doenças nos cultivos convencionais de batata requer emprego de maior quantidade de produtos fitossanitários e de maior toxicidade em relação ao cultivo orgânico, que pode acarretar riscos a saúde humana e impacto ambiental. Este trabalho teve como objetivo avaliar o rendimento e a reação de genótipos de batata à requeima e à pinta preta sob sistema orgânico de cultivo. Os experimentos foram conduzidos a campo nas safras 2012/2013 e 2013/2014 em Lages/SC e em Quilombo/SC. O delineamento experimental foi de blocos ao acaso com quatro repetições. Avaliou-se oito clones locais oriundas da serra catarinense: SJ01273-1; SJ01251-1; SJ01213-1; SMSJ07344-54; SJ04510-1; SJ05621-11; SJ02411-5; SJ04521-3 e oito cultivares comerciais: Ágata, Asterix e Monalisa de origem holandesa; Panda de origem alemã e BRS Ana, BRS Eliza, Cota e Catucha de origem brasileira. Foram realizadas avaliações de incidência e severidade da requeima e pinta preta e do peso e número de tubérculos produzidos. Os genótipos de batata apresentaram variabilidade na produção de tubérculos e de resistência a doenças. O clone regional 15 e as cultivares BRS Ana e Cota apresentaram resistência à pinta preta e a requeima, em ambos os locais cultivados. O genótipo 35 e as cvs. Asterix e BRS Ana apresentaram as maiores produções. O genótipo 35 foi o mais produtivo (16.926,81kg ha-1). Genótipos locais de batata apresentam variabilidade quanto ao potencial produtivo e resistência a doenças sob o sistema orgânico de cultivo, evidenciando fonte de resistência a programas de melhoramento genético.

Different timing of whitefly control and soybean yield / Controle da mosca-branca em diferentes momentos e a produtividade da soja

Trials were carried out in Paraúna, Goiás, Brazil, to evaluate the impact of whitefly on soybean yield. The experimental design was a randomized block, with four treatments and four replications (10m x 20m). The treatments were different levels of infestation, managed by applying insecticide at different timing; the control was kept free of insects by weekly insecticide spraying. The number of insects per leaflet was evaluated weekly, and at harvest the yield (kg ha-1) and the weight of 100 seeds (g) were recorded. The soybean was tolerant to whitefly, since only the treatment where nymphs per leaflet reached 136.31±26.60 (treatment without the use of insecticides) was sufficiently severe to cause yield loss. This loss was likely associated with the sooty mold, caused by the fungus Capnodium sp. that develops in the sugary secretion produced by the whitefly on the surface of plant leaves. Therefore, insecticides should only be sprayed when a whitefly infestation is sufficiently severe to trigger the growth of sooty mold. The relationship between insect number per leaf and the growth of sooty mold still needs to be determined for different soybean cultivars, as well as for different environmental conditions.

Experimentos foram conduzidos em Paraúna, Goiás, Brasil, avaliando o impacto da mosca-branca na produção de soja. O delineamento experimental foi em blocos ao acaso, com quatro tratamentos e quatro repetições (10m x 20m). Os tratamentos foram diferentes níveis de infestação, obtidos pela aplicação de inseticidas em diferentes momentos; a testemunha foi mantida livre do ataque da praga, aplicando-se inseticida semanalmente. O número de insetos por folíolo foi avaliado semanalmente e, na colheita, foi avaliada a produtividade (kg ha-1) e o peso de 100 sementes (g). A soja foi tolerante à mosca-branca, visto que apenas o tratamento em que as ninfas por folíolo atingiram a média de 136,31±26,60 (tratamento sem aplicação de inseticidas) foi severo o suficiente para causar perdas de produtividade. Essa perda foi provavelmente associada à formação de fumagina, causada pelo fungo Capnodium sp., que se desenvolve nas secreções açucaradas produzidas pela mosca-branca na superfície das folhas. Portanto, inseticidas precisam apenas ser aplicados quando a infestação de mosca-branca for severa o suficiente para propiciar a formação de fumagina. Entretanto, a relação entre o número de insetos por folíolo e a formação de fumagina ainda precisa ser determinada para diferentes cultivares, assim como para diferentes condições ambientais.