Agente etiológico e sintomas da podridão do colo em cladódios de pitaias

As pitaias são cactáceas frutíferas que têm ganhado relevância no cenário da fruticultura nacional como uma alternativa para diversificação da produção de frutas. Apesar disso, os problemas fitossanitários têm preocupado os produtores brasileiros. Em duas áreas experimentais da Universidade do Estado de Mato Grosso, Campus de Nova Xavantina, observou-se a incidência de podridão do colo em 100% das pitaias vermelhas e em 42% em pitaias vermelhas e amarelas. Embora a ocorrência de doenças venha se destacando como fator limitante para produção de pitaias, os estudos sobre o manejo fitossanitário da cultura no país ainda são escassos. Diante do exposto, objetivou-se com o presente trabalho identificar o agente etiológico e descrever a evolução dos sintomas da podridão do colo em cladódios de pitaias amarelas e vermelhas em Nova Xavantina (MT). No pomar experimental do Campus de Nova Xavantina da Universidade do Estado de Mato Grosso foram observadas lesões no colo de plantas de pitaias. O material sintomático foi coletado e enviado para a Clínica Fitossanitária do Departamento de Fitopatologia da Universidade Federal de Lavras para diagnose do agente patogênico. A descrição dos sintomas foi realizada por meio de registro fotográfico semanal das lesões. A partir do laudo fitossanitário pode-se diagnosticar como possível causador da podridão no colo das plantas de pitaia os fungos do gênero Rhizopus. A podridão no colo apresentou inicialmente lesão clorótica de cor amarelo intenso que evoluiu para a cicatrização da lesão sem a necessidade de controle fitossanitário

Qualidade fisiológica de sementes de berinjela osmocondicionadas

Eggplant seeds germination can be slow and uneven, justifying the use of pre-germinative treatments to improve the performance of seed lots. One option of treatment is the controlled hydration of seeds by priming. In this way, this study aimed to evaluate the performance of eggplant seeds cv. Embu submitted to different methodologies of priming. The seeds used in the experiment were stored in cold chamber (15º C and 55% RH) in paper bags. The research was carried out at Central Laboratory of Seeds/UFLA. The seeds were submitted to the priming in aerated solutions varying the following factors: temperature (15º C and 25º C), time (24, 48 and 72 hours) and solution (water, PEG, KNO3 and PEG+KNO3). Seeds were washed in running water and dried at 30º C, until the return to the initial moisture content, around 10%. The variables analyzed were percentage of germination, percentage of emergence, speed index of emergence and electrical conductivity. The treatments were arranged in a completely randomized design, according to a factorial arrangement 2x3x4+1 (control - seeds without priming). The results showed that priming improves the vigour of eggplant seeds with no effect on viability; the priming in water or KNO3 is efficient to improve the seed vigour and priming in water or KNO3 may use temperature of 15º C or 25º C for 24, 48 or 72 hours

Qualidade fisiológica de sementes de berinjela osmocondicionadas submetidas à secagem

The objective of this work was to evaluate the physiological quality of osmoprimed eggplant seeds subjected to drying. Eggplant seeds of the cultivar Embu, primed in aerated KNO3 (‑0.8 MPa) solution, at 25ºC, for 48 hours, were used. The seeds were subjected to the following procedures: reduction of initial moisture content (r), heat shock (CT), and slow (SL) or fast drying (SR) for 48 hours. The combination of these procedures formed the treatments: primed seeds without drying, SL, SR, CTSL, CTSR, rSL, rSR, rCTSL, and rCTSR, besides a control (seeds without priming). Seeds primed and those dried slowly expressed higher germination percentage. No difference was observed among treatments for seedling emergence percentage. The control took more time to express maximum emergence than the other treatments. Seeds subjected to heat shock presented higher values of electrical conductivity than those that did not undergo this treatment. The physiological quality of eggplant seeds gained with priming is maintained after drying. The drying of primed eggplant seeds should be preferably performed slowly, with or without reduction of initial moisture content.O objetivo deste trabalho foi avaliar a qualidade fisiológica de sementes de berinjela osmocondicionadas submetidas à secagem. Utilizaram-se sementes de berinjela, cultivar Embu, condicionadas em solução aerada de KNO3 (‑0,8 MPa), a 25ºC, por 48 horas. As sementes foram submetidas aos seguintes procedimentos: redução do teor de água inicial (r), choque térmico (CT) e secagem lenta (SL) ou rápida (SR) por 48 horas. As combinações desses procedimentos constituíram os tratamentos: sementes condicionadas e sem secagem, SL, SR, CTSL, CTSR, rSL, rSR, rCTSL e rCTSR, além da testemunha (sementes sem condicionamento). As sementes condicionadas e as secas lentamente expressaram maior percentagem de germinação. Não houve diferença entre os tratamentos quanto à percentagem de emergência de plântulas. A testemunha levou mais tempo para alcançar a máxima emergência do que os demais tratamentos. As sementes submetidas ao choque térmico apresentaram maiores valores de condutividade elétrica do que as que não passaram por esse tratamento. A qualidade fisiológica das sementes de berinjela obtida com o condicionamento é mantida após a secagem. A secagem de sementes de berinjela condicionadas deve ser realizada preferencialmente de forma lenta, com ou sem redução do teor de água inicial

Physiological quality of osmoprimed gherkin seeds

It was aimed to verify the effect of different methodologies of osmopriming on physiological quality of gherkin seeds. Prior, it has been characterized the initial profile of the gherkin seeds. Then, the seeds were osmoprimed in gerboxes containing two blotter papers wetted with osmotic solutions in a volume equal to three times the paper dry weight and kept in BOD at 15 °C. After the priming, the seeds were dried at room temperature for 48 hours. Then, the following variables were evaluated: seeds moisture content, percentage of germination, percentage of emergence, emergence speed index and electrical conductivity. The analyses of variances were realized according to a randomized design in a factorial scheme 3 x 2 x 4: three solutes (polyetilene glycol 6000 - PEG, potassium nitrate - KNO3 and PEG + KNO3), two osmotic potentials (-0.55 and -1.10 MPa) and four times of priming (24, 48, 72 and 96 hours), followed by analyses of regression. It is concluded that the priming has no effect on germination and affects positively the vigor of the gherkin seeds lots; osmopriming with potassium nitrate is effective in improving the physiological quality of gherkin seeds lot

EMERGÊNCIA E QUALIDADE DE MUDAS DE Copernicia prunifera EM FUNÇÃO DA EMBEBIÇÃO DAS SEMENTES E SOMBREAMENTO

The increase of the shrimp and fruit crop has devastated the carnauba, evidencing the importance of reforest projects and of researches aiming to the production of seedlings. It was aimed to evaluate the effect of imbibition of seeds and shading on the emergence and quality of carnauba seedlings. The treatments were disposed in a randomized design arranged in split-plot with the shading conditions (without shading and shading all day, during the morning and during the afternoon) as the main factor and the types of seeds (imbibed and non-imbibed seeds) as secondary factor. The imbibed seeds were immersed in water until the protrusion of the cotyledonary petiole. To the shading conditions was used black screen (50%). After 120 days of the sowing, we evaluated the percentage (PE), speed index (IVE) and mean time of emergency (TME), the ratio between the aerial part length and stem¿s diameter (CPA/DC) and quality index of Dickson (IQD). By the PE and IVE, higher viability was verified and vigor in imbibed seeds. By the TME, higher vigor was observed to the seedlings produced under full sunshine and with shading during the afternoon, which had higher quality according to CPA/DC. By the IQD, better balance was observed in the seedling from imbibed seeds and in the seedlings produced under full sunshine. It is concluded that the carnauba seeds imbibition provides higher emergency percentage, accelerates this process and provides better quality of seedlings. Carnauba seedlings produced under full sunshine presents faster emergency and higher quality