Aspectos físicos e fisiológicos de sementes de Fimbristylis dicothoma relacionados à germinação e dormência

In the seeds of pioneer plants, the application of treatments for breaking dormancy, and selection by colour and size, are strategies for obtaining seeds of less dormancy and better germination performance. The aim of this study was to evaluate the effect of the physical and physiological aspects of seeds of the tall fringe-rush (Fimbristylis dichotoma) on germination and dormancy. To do this, the seeds were submitted to the following treatments in three studies: (i) control, immersion in H2SO4 (98%, 36N) for 1 minute, immersion in KNO3 (1, 2 and 3%) for 15 minutes, seeding on a substrate moistened with KNO3 (0.2%) and exposure for 5 and 10 hours in a forced air circulation oven at 40 and 70 degrees C; (ii) classification of the seeds by colour (light and dark) and application of the following treatments: control, immersion of the seeds in H2SO4 (98%, 36N) for 1 and 2 minutes, immersion in KNO3 (5% and 10%) for 15 and 30 minutes and seeding on a substrate moistened with KNO3 (0.2%); (iii) classification by size (0.60, 0.50 and 0.40 mm) and germination on a substrate moistened with KNO3 (0.2%) or distilled H2O. The seeds were evaluated by germination test, first count and germination speed index. Moistening the substrate with KNO3 (0.2%), and heat treatment at 40 degrees C for 10 hours improve performance in seeds of the tall fringe-rush. Light-coloured seeds do not display dormancy. Medium-sized seeds of the tall fringe-rush show better performance in terms of percentage and speed of germination.

Seletividade do clomazone em sementes de algodão tratadas com dietholate e acetato de zinco

The objective of this study objective was to evaluate the selectivity of pre-emergence applications the herbicide clomazone cotton seeds treated with dietholate and zinc acetate. The 4 x 2 factorial arrangement was adopted (4 seed treatment methods and 2 clomazone dosages), distributed in a randomized block design with 4 repetitions. In treatments where dietholate and zinc acetate were applied, rates of 0.4 kg ha(-1) and 8 ml per kg of seeds were used respectively. The clomazone rates used refer to 0.8 and 1.0 kg ha(-1). The cotton cultivar used was the Fiber Max 966 LL. Independent of treatment, all seeds were treated with tiametoxam insecticide and fludioxonil + metalaxyl-M fungicide at rates of 2.24 and 0.08 + 0.03 g per kg of seed, respectively, to control pests early and limit losses caused by pathogens in germination and seedling emergence. Dietholate and zinc acetate treatment had greater initial effect on cotton plants at 21, 30 and 45 days after application. In phytointoxication symptoms were observed for treatment with dietholate and zinc acetate during the evaluation periods. Seeds treated with dietholate, dietholate and zinc acetate or zinc acetate alone provided a higher number of bolls and seed cotton production compared to the control.

Tempo de trânsito gastrointestinal de diferentes frutos e taxa de germinação de Morus nigra pós passagem pelo trato em Sabiás-barranco (Turdus leucomelas)

Seed dispersal is a key process in the life cycle of plant species and may determine the dynamics of their populations. The passage of the fruit from the gastrointestinal tract brings effects on energy and nutritional rewards for the bird. The retention time of the seeds is an essential factor for the dispersion, affecting the dispersal distance. Some factors determine it, as the size of the bird, degree of frugivory, chemical composition of the fruit, the number and size of seeds. The study sought to characterize the Morus nigra seed retention time in three species of thrushes and compare them with other species of birds and plants. The blackberry, exotic species with socio-economic importance in Brazil, produces aggregate fruit having up to 60 seeds. Have been kept in captivity individuals leucomelas Turdus rufiventris thrush, thrush and amaurochalinus, native and omnivorous species, important dispersers in degraded areas, inhabiting the urban and the natural environment. In 274 samples of feces was recorded about 500 mulberry seeds. The first record of seeds was in 15 minutes (n = 2) and the last to 115 minutes (n = 4) after eating the fruit. The average time of gastrointestinal transit of seed for the three species was 52 minutes and 80% were defecated to 65 minutes post ingestion. Taking into consideration the type of fruit and the species of bird, there is great variation in the retention time when compared to other species of birds, being in general slower. That way, can be increase the degree of dispersion of the seed to more distant areas of the mother plant, increasing the chances of survival of seedlings, according to the hypothesis Janzen and Connell. The Turdus It showed efficient dispersers Morus nigra seeds, and inhabits natural and urbanized environment, the possibility of exchange of these seeds between environments by the action of thrushes

Emprego do extrato de Moringa (Moringa oleífera Lamarck) na clarificação do caldo de cana para produção de açúcar e etanol

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Baccharis dracunculifolia DC. (Asteraceae): composição do óleo essencial, diversidade e parâmetros genéticos

Pós-graduação em Agronomia (Horticultura) - FCA

Qualidade dos processos mecanizados de semeadura e colheita na cultura da soja

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Manejo da adubação nitrogenada para a cultura do feijão em sucessão a gramíneas forrageiras cultivadas para produção de sementes

Pós-graduação em Agronomia (Agricultura) - FCA

Temperatura, luz e tolerância à dessecção na germinação de sementes de açaí-do-Amazonas

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Re-indução da tolerância à dessecação em sementes germinadas de feijão-caupi (Vigna unguiculata )L. (Walp.))

Pós-graduação em Agronomia (Agricultura) - FCA

Desenvolvimento in vitro e criopreservação de sementes de orquídeas

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Germinação de sementes de maracujazeiros: água, luz, temperatura e reguladores vegetais

The production of seedlings of passion fruit is done mainly with the use of seeds by most producers. It can also be propagated by cuttings, layering and in vitro tissue culture. However, even when grafting is used, it is necessary to use seeds to produce the rootstock. Nevertheless, most Passifloracea species have germination problems, making it difficult to obtain seedlings. Although several studies have been developed in an attempt to increase seed germination of passion fruit there are still difficulties in understanding the germination process and also disagreement about seed dormancy. Thus, the present study aimed to review papers related to seed germination of passion fruit emphasizing aspects such as mechanical resistance to water ingress, the need for adequate light and temperature and the use of plant growth regulators in overcoming seed dormancy. It was noticed that, in general, the passion fruit seeds are photoblastic negative and exhibit physiological dormancy, being no need of seed scarification to stimulate its germination.

Manutenção da diversidade agrícola em assentamentos rurais: um estudo de caso em Moji-Mirim - SP, Brasil

Maintenance of agricultural diversity in rural settlements – a case study in Moji-Mirim, São Paulo, Brazil. This paper investigated whether farmers, when established in rural settlements, keep some traditional features with regard to crops diversity and circulation of planting material. Its aims were to make an ethnobotanical survey of species and varieties and analyze the dinamics of seeds and propagules circulation. A total of 139 varieties of food crops (55 species/28 families) were found, being 87% of them intended for self-consumption; 54% of varieties come from Minas Gerais, home state of most respondents. The number of varieties grown per household ranged from 17 to 54. The informal and free circulation of planting material is the most important way of acquisition. The circulation network is very active, showing a potential for the management of crops diversity, with emphasis on the contribution of settlers to the maintenance and valorization of traditional varieties.

Vibração de plantas de pimenta Malagueta para produção de frutos e sementes em ambiente protegido

This study aimed to verify the effect of vibration of plants in the production of fruits and seeds and in the physiological quality of the seeds of the “Malagueta” pepper in a protected cultivated area with open and closed sides. The experiment was conducted at the Experimental Farm of the School of Agronomic Sciences of Universidade Estadual Paulista (FCA/UNESP), located in the city of São Manuel (SP). Two treatments were carried out, which consisted of plants that did and did not undergo vibration. Plants were vibrated manually by swinging the wire attached to the supporting bamboo for about 5 seconds, twice a day for 11 weeks. The design was a randomized block with six repetitions. The same experiment was conducted in two protected environments, with and without anti-aphids screens on the sides, cultivated in the same season. For the comparison of environments, a combined analysis was performed considering each environment as a separate experiment. The characteristics evaluated were: weight and number of fruits per plant; weight, diameter and length of fruit; weight and amount of seeds per fruit; and plant height. For the analysis of seed quality, the characteristics evaluated were: germination percentage; first count of germination; dry matter of seedlings; seedling emergence in substrate; and seedling emergence speed index. Regardless of the environment, vibration affects the physiological quality of seeds. The presence of pollinator insects benefited the production and quality of “Malagueta” pepper seeds and increases the fruit weight.

Eggplant production in a protected environment with plant vibration

The aim of this study was to evaluate the production of eggplant fruit according to plant vibration in two types of protected environments, with and without an aphid-proof screen, preventing or permitting the entry of pollinators. Two eggplant hybrids (Roxelle, clear purple color and round shape fruits, and Kokushi, purple color and elongated fruits), two vibration treatments (with or without plant vibration), and two environments (with or without screen) were assessed. It was concluded that the presence of insects in the open environment increases marketable fruit yield only in hybrid Roxelle (2120 and 1172 g plant-1, with and without insects, respectivelly), the number of seeds per fruit in both hybrids in treatment without plant vibration (average of 584 and 110 seeds, with and without insects, respectivelly), and that plant vibration may partially replace the absence of pollinator insects in a closed environment protected with a screen, with an increase in fruit yield.

Uso do fluxofenim em trigo como protetor ao herbicida S-metolachlor

This work aimed to evaluate the effectiveness of fluxofenim used for seed treatment as safener in wheat, Ônix cultivar, treated with the herbicide S-metolachlor applied in pre-emergence. The study was divided in two steps. The first step consisted of an evaluation of fluxofenim’s safener potential for the reduction of visual symptoms of S-metolachlor injury in the field, and the treatments were S-metolachlor at 1,440 and 2,880 mL i.a. ha-1 and fluxofenim at 0, and 40 mL per 100 kg of seeds, and a control without herbicide. The second step was to evaluate glutathione S-transferase activity (GST). Herbicide phytotoxity was measured by way of visual symptoms at 3, 7, 15, and 30 days after emergence (DAE), dry matter from roots and leaves at 10 DAE. For the determination of GST activity, the canopy of plants was collected at 10 DAE and 15 days after treatment application. The wheat presented low tolerance to S-metolachlor at both rates, and fluxofenim increased S-metolachlor selectivity to wheat but not sufficiently, reducing plant population to a nonacceptable level. Gluthationa S-transferase activity for wheat increased when seeds treated with fluxofenim were submitted to S-metolachlor at 1,440 mL a.i. ha-1.