Maturation and physiological quality of IAC-863 Rangpur lime seeds

There is a growing demand for high quality seeds to obtain citrus rootstocks. Normative Instruction 48 (MAPA) of September 24, 2013, requires minimum of 50% germination for the marketing of citrus seeds. Harvest season is one of the stages of seed production with great importance to ensure quality, which makes knowing its maturation process an important step. Thus, the objective of this study was to monitor physicochemical changes in IAC-863 Rangpur lime fruits in order to characterize the physiological maturity of seeds, and to define the ideal harvest point in order to obtain seeds with high physiological quality to obtain rootstocks. Physicochemical analysis of fruits (mass loss, color, soluble solids and acidity) and analysis of seeds (water content, germination and emergence) was performed. Higher germination results were observed in seeds obtained from fruits with higher color index and soluble solids content. The storage of IAC-863 Rangpur lime fruits after harvest increases germination rate, especially in mid-season fruits.There is a growing demand for high quality seeds to obtain citrus rootstocks. Normative Instruction 48 (MAPA) of September 24, 2013, requires minimum of 50% germination for the marketing of citrus seeds. Harvest season is one of the stages of seed production with great importance to ensure quality, which makes knowing its maturation process an important step. Thus, the objective of this study was to monitor physicochemical changes in IAC-863 Rangpur lime fruits in order to characterize the physiological maturity of seeds, and to define the ideal harvest point in order to obtain seeds with high physiological quality to obtain rootstocks. Physicochemical analysis of fruits (mass loss, color, soluble solids and acidity) and analysis of seeds (water content, germination and emergence) was performed. Higher germination results were observed in seeds obtained from fruits with higher color index and soluble solids content. The storage of IAC-863 Rangpur lime fruits after harvest increases germination rate, especially in mid-season fruits

Physiological quality of citrandarins, Poncirus trifoliata and Sunki mandarin seeds

Rangpur lime is the rootstock most used in Brazil, mainly due to its resistance to drought; however, it is susceptible to several diseases, requiring the search for other rootstocks tolerant to factors limiting citrus cultivation. In addition, the Brazilian legislation stipulates that citrus seeds can only be commercialized with at least 50% germination rate. Thus, the aim of this work was to evaluate the physiological quality of seeds of seven citrus rootstocks. The following citrus fruits were harvested: Poncirus trifoliata, Sunki mandarin and their hybrids –citrandarins (70, 106, 254, 299 and 310). Fruit mass, diameter and height were measured. Seeds were extracted from fruits, counting the number of normal seeds (not aborted). Seeds were dried up to 20% water content and stored for 3, 6, 9 and 12 months. The physiological quality of seeds was evaluated before storage (time 0) up to 12 months of storage. The quality of Poncirus trifoliata, Sunki mandarin and citrandarins 70, 106, 254, 299 and 310 seeds was reduced during storage. However, their germination rate remained above 50%, evidencing that seeds of all rootstocks could be marketed until 12 months of storage. The new rootstocks tested have seeds with physiological quality compatible with their parents, in compliance with current legislation.Rangpur lime is the rootstock most used in Brazil, mainly due to its resistance to drought; however, it is susceptible to several diseases, requiring the search for other rootstocks tolerant to factors limiting citrus cultivation. In addition, the Brazilian legislation stipulates that citrus seeds can only be commercialized with at least 50% germination rate. Thus, the aim of this work was to evaluate the physiological quality of seeds of seven citrus rootstocks. The following citrus fruits were harvested: Poncirus trifoliata, Sunki mandarin and their hybrids –citrandarins (70, 106, 254, 299 and 310). Fruit mass, diameter and height were measured. Seeds were extracted from fruits, counting the number of normal seeds (not aborted). Seeds were dried up to 20% water content and stored for 3, 6, 9 and 12 months. The physiological quality of seeds was evaluated before storage (time 0) up to 12 months of storage. The quality of Poncirus trifoliata, Sunki mandarin and citrandarins 70, 106, 254, 299 and 310 seeds was reduced during storage. However, their germination rate remained above 50%, evidencing that seeds of all rootstocks could be marketed until 12 months of storage. The new rootstocks tested have seeds with physiological quality compatible with their parents, in compliance with current legislation

Recobrimento de sementes de milho com ácidos húmicos e bactérias diazotróficas endofíticas

The objective of this work was to evaluate the effect of seed coating of maize with humic acid (HA), endophytic diazotrophic bacteria, and the combination of both, on plant growth stimulation and bacteria population establishment in roots of inoculated plant host. The addition of HA, bacteria, and the combined use of bacteria and HA stimulated plant growth. Humic acids used in the coated seed formulation show diminished capacity for stimulation of root growth compared with its use in solution. Seed coat is an option for inoculation of endophytic diazotrophic bacteria like Herbaspirillum seropedicae (Z67).O objetivo deste trabalho foi avaliar o efeito do recobrimento de sementes de milho com ácidos húmicos (AH), bactérias diazotróficas endofíticas e o uso em conjunto de AH e bactérias diazotróficas endofíticas, na estimulação do crescimento vegetal e na população de bactérias estabelecidas na planta hospedeira. A adição de AH, bactérias e o uso em conjunto estimularam o crescimento vegetal. Os AH utilizados no recobrimento de sementes de milho têm menor capacidade de estimular o crescimento radicular, em comparação ao uso em solução. O recobrimento de sementes é uma opção de inoculação de bactérias diazotróficas endofíticas da espécie Herbaspirillum seropedicae (Z67)

Postharvest longevity of Fremont IAC 543 mandarin

Abstract The planting of new types of table citrus is an interesting alternative for citrus growers in the state of Paraná, as this domestic market continues to grow and needs innovation. Thus, the aim of this study was to evaluate the acceptance and storage of a new hybrid for the region of Londrina / PR, Fremont IAC 543 mandarin (Citrus clementina hort. ex Tan x C. reticulataBlanco). Treatments were: storage of fruits with and without wax coating at room temperature [21 ± 2 °C and relative humidity (RH) = 60 ± 5%] for up to 36 days. Sensory (acceptance test and purchase intention) and physicochemical analyses [weight, juice yield, acidity, soluble solids and soluble solids/titratable acidity (ratio)] were performed before and after storage. Physicochemical data were submitted to analysis of variance and regression, while sensory analysis results were explored through descriptive statistics and principal components analysis using the R statistical software. It could be concluded that Fremont IAC 543 mandarin can be stored with wax coating and at room temperature without losing its quality characteristics for a period of up to 18 days

Root system of seedlings as vigor indicative and biostimulant effect in bean and corn seeds

Objetivou-se, com este trabalho, avaliar a qualidade fisiológica das sementes de milho e feijão utilizando como referência o sistema radical das plântulas; verificar o efeito da massa das sementes de feijão na sua qualidade fisiológica e no sistema radical das plântulas; avaliar o efeito do biestimulante Stimulate em sementes de milho e feijão. Para obter lotes de diferentes qualidades fisiológicas e assim avaliar o sistema radical das plântulas de milho, as sementes da variedade UFV-M100 Nativo foram colhidas em diferentes épocas ou submetidas a diferentes métodos de debulha. A massa das raízes seminais secas apresentou potencial para diferenciar o vigor de lotes colhidos em diferentes épocas de colheita; no entanto, as características das raízes seminais não diferenciaram os lotes submetidos a danos mecânicos durante a debulha. Para obter lotes de sementes de feijão de diferentes qualidades, e assim avaliar o sistema radical das plântulas, as sementes da cultivar Carnaval MG foram secas em diferentes temperaturas ou submetidas a diferentes métodos de debulha. O número de verticilos, o número e comprimento das raízes basais diferenciaram o vigor de lotes submetidos a diferentes temperaturas, mas não foram eficientes para diferenciá-los em relação aos danos mecânicos. A massa das sementes de feijão não influenciou a qualidade fisiológica das sementes, mas tem efeito sobre o sistema radical, especificamente sobre o comprimento e a massa das raízes basais. Nas avaliações com Stimulate, o tratamento das sementes de feijão e de milho com ele não influenciou a qualidade fisiológica das sementes e o sistema radical das plântulas.The objective of this work was to evaluate physiology quality of corn and bean seeds by using root system of seedlings as reference; to verify the effect of beans seed mass on its physiologic quality and on the root system of seedlings; to evaluate the effect of Stimulate biostimulant on seeds of corn and beans. To obtain lots with different physiologic quality and thus to evaluate root system of corn seedlings, UFV-M100 seeds were harvested at different seasons or submitted to different threshing methods. Mass of dry seminal roots presented potential to differentiate vigor of lots harvested in different season; however characteristics of seminal roots did not differentiate lots submitted to mechanical damage. To obtain lots of bean seeds with different qualities and therefore to evaluate root system of the seedlings, Carnaval MG cultivar seeds were dried at different temperatures or submitted to different threshing methods. The number of whorls, the number and length of basal roots differentiate vigor of lots submitted to different temperatures but they were not efficient to differentiate them in relation to mechanical damage. Mass of bean seeds did not influence physiologic quality of the seeds but it does have effect on root system, specifically on length and mass of basal roots. In evaluations with Stimulate, treatment with bean and corn seeds with Stimulate did not influence physiologic quality of seeds and root system of seedlings.Conselho Nacional de Desenvolvimento Científico e Tecnológic

Efeito dos ácidos húmicos na inoculação de bactérias diazotróficas endofíticas em sementes de milho Effect of the humic acids in endophytic diazotrophic bacteria inoculation in corn seeds

Os ácidos húmicos podem atuar no aumento da população de bactérias diazotróficas introduzidas no interior da planta e, consequentemente, no incremento dos efeitos benéficos sobre a planta hospedeira. Com este trabalho, objetivou-se avaliar o efeito dos ácidos húmicos na inoculação de bactérias diazotróficas endofíticas, em sementes de milho. Foi utilizada a estirpe Herbaspirillum seropedicae Z67 BR 11175. A inoculação das sementes com as bactérias e a adição de ácidos húmicos foram realizadas pelo recobrimento das sementes de milho UENF 506-8, com a mistura de calcário, meio de cultura semisólido, água e cimentante. As sementes recobertas foram semeadas em vasos Leonard. Aos 40 dias após a semeadura, as plântulas foram coletadas, e foi realizada a contagem de bactérias nas raízes pela técnica do Número Mais Provável. Os resultados deste trabalho mostram que os ácidos húmicos não interferem negativamente no crescimento das bactérias e estimulam a colonização da microbiota nativa. No entanto, nas condições avaliadas, a aplicação conjunta de bactérias + ácidos húmicos não estimulou o crescimento da população de bactérias inoculadas nas plântulas de milho.The objective of this research was to evaluate the effect of the humic acids in the inoculation of endophytic diazotrophic bacteria in corn seeds. It was used the bacteria Herbaspirillum seropedicae Z67 BR 11175. The inoculation of the seeds with the bacteria and the addition of humic acids were accomplished by the coating of the corn seeds UENF 506-8. The coating was accomplished with a mixture of lime, semi-solid middle culture, water and cement. The seeds covered were sown in Leonard vases. Forty days after sowing the plants were collected and the bacteria couting was accomplished in the roots by the Most probable Number technique. The results showed that the humic acids doesn't interfere negatively in the bacteria growth of and they stimulate the colonization of the native microbiota. However, in the appraised conditions, the united application of bacteria + humic acids didn't stimulate the growth of the bacteria population inoculated in the corn seedling