Avaliação do vigor de sementes de rúcula pelo teste de lixiviação de potássio

The objective of this study was to evaluate methodologies for the potassium leaching test and to verify its sensitivity for identifying different levels of vigor of arugula seed lots. Five seed lots each of Rucula Cultivada and Rucula Gigante were used. Standard germination, first count of germination, seedling emergence and variations of the potassium leaching test (50 or 100 seeds imbibed in 50 mL or 75 mL in water; at 25 °C and 30 °C; for 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3, 4 and 5 hours) were done. It was observed that the period seeds need to be soaked can be reduced to 2 hours and the water volume can be reduced to 50 mL. The utilization of 50 seeds showed a smaller variation coefficient and the best temperature was 30 °C. It can be concluded that the potassium leaching test for arugula seeds can be run using 50 seeds in 50 mL of water for 2 hours at 30 °C.

Custo de produção e indicadores de rentabilidade da cultura do milho safrinha

The objective of this study was to evaluate the production cost and profitability of the second season corn crop in the Medio Paranapanema region, São Paulo State Brazil, under two technological levels (middle and high technology), crop 2008/2009, and compare the results with the 2006/2007 agricultural year. Effective and total operational cost as well as five profitability indicators were used. It was concluded that the high technology production cost for corn crop (direct seedling, sowing during the recommended period, use of simple hybrid seed, application of side-dressing fertilization, and treatment of seeds with different insecticides) was superior to the middle technology production cost (direct seedling, sowing after the recommended time, use of double hybrid seed, and no side-dressing fertilization). However, the average cost was inferior (US$ 8.5), due to a higher yield (4 t). The high technology corn crop was profitable (gross income and profitability index of 14% and 12%, respectively). For the middle technology crop, profitability indexes pointed out that the cropping system needs to be reevaluated by technicians and research institutions, regarding the adequate technical recommendations. Profitability indexes decreased considerably in both cropping systems. It was verified that, in relation to the 2006/2007 harvest period, the total operational cost increased for both technologies, mainly because of the increase of supplies prices.

Capim-colonião e seus efeitos sobre o crescimento inicial de clones de eucalyptus × urograndis

This study aimed to evaluate the guinea grass effect (Panicum maximum) on the initial growth of different Eucalyptus × urograndis clones. Two assays were established with eucalyptus clones and guinea grass seedlings. The plants were grown in plots with cement borders filled with soil. Each plot received a eucalyptus seedling. The first assay had a completely randomized experimental design, with three replications, and treatments in a 5x2 factorial scheme (five eucalyptus clones and the absence or presence of two guinea grass plants at 10 cm distance from eucalyptus seedling). The second assay was similar to the first, however with three eucalyptus clones. The experimental design was completely randomized, with five replications, and a 3x2 factorial scheme (three eucalyptus clones and the absence or presence of two guinea grass plants). The presence of eucalyptus clones did not affect guinea grass development. The eucalyptus clones that coexisted with guinea grass plants did not show differences in their development, making the clones equal when under competition. The most susceptible characteristics of eucalyptus clones to guinea grass were foliar area, shoot and stem dry matter. Clone 3 showed the most sensitivity to guinea grass, and clone 1 was the most tolerant, but all clones studied suffered a negative interference from guinea grass.

Resistance of rose rootstocks to Meloidogyne hapla nematode

Roses are widely used in landscaping. One of the most important fitossanitary problems of this ornamental plant in gardens is the fitonematodes, especially Meloidogyne hapla, which is the most important one in colder climate regions. This work had the objective of study the resistance of nine rose rootstocks (Rosa multiflora 'Paulista', R. multiflora 'Japanese', R. multiflora 'Iowa', R. multiflora 'Kopman's', R. indica × multiflora, R. indica 'Mayor', R. sp. 'Natual Brier', R. manetti and R. canina 'Inermis') to Meloidogyne hapla nematode. Ten replications of each rootstock were used. The roots, collected in a commercial area of cut roses, visually had galls there were isolated and identified. The inoculum of M. hapla was previously produced in rose and tomatoes seedlings under greenhouse conditions. The plants were harvested ninety days after inoculation. The roots were washed and the number of eggs and juveniles recuperated in the root system of each plant was estimated by the Final Population (FP), and the Reproductive Factor (RF) was calculated. The rootstocks with RF<1 values were considered resistant, and the ones with RF>1, susceptible. Rosa manetti and Rosa sp. 'Natual Brier' rootstocks showed the lowest values for RF, indicating that, although they are susceptible, they provide the lowest nematode reproduction. Based on the RF values, it was concluded that all the rose rootstocks evaluated were susceptible to M. hapla nematode.

Morfologia de sementes e de estádios iniciais de plântulas de espécies de Bromeliaceae da Amazônia

Seeds of Aechmea bromeliifolia, A. castelnavii (Bromelioideae); Dyckia duckei, D. racemosa (Pitcairnioideae) and Tillandsia adpressiflora (Tillandsioideae) were collected in the Amazon regions (Mato Grosso) and studied to describe morphological characterization and post-seminal development, which can be taxonomically useful, and to assess percent germination. All the species have epigeous germination and produce cryptocotyledonary plantlets. Seeds have no dormancy and percent germination is high (over 86%), which facilitates the production of seedlings and conservation studies. Exclusive characteristics of the genera include: the seed coat of Aechmea (Bromelioideae) has mucilage that prevents desiccation; whereas that of Dyckia (Pitcairnioideae) has membranaceous wings and that of Tillandsia (Tillandsioideae) has feathery appendages, both of which make dispersal easier and establish the epiphytic habit. Initial post-seminal development of Aechmea (Bromelioideae) and Dyckia (Pitcairnioideae) is marked by the emergence of primary roots, interpreted as a basal character, whereas that of Tillandsia adpressiflora (Tillandsioideae) is marked by the emergence of the cotyledon, interpreted as a derived character. Dyckia and Tillandsia have a small tank only in the seedling phase while the contrary occurs in Aechmea.

Avaliação de substratos na emergência de plântulas de araticum-de-terra-fria (Annona emarginata (Schltdl.) H. Rainer)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Qualidade fisiológica de sementes de diferentes árvores matrizes de Corymbia citriodora (Hook.) K.D.Hill & L.A.S. Johnson

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Germinação e vigor de sementes de crambe sob estresse hídrico

This study aimed to evaluate crambe seeds germination and vigor under water stress conditions induced by polyethylene glycol solutions. The seeds were germinated on substrate moistened with polyethylene glycol solutions, using the osmotic potentials of 0 (control), -0.2, -0.4, -0.6, -0.8, -1.0, -1.2 and -1.4 MPa. The seeds germination was evaluated by normal seedlings and root emission percentages. Vigor was evaluated by germination average time, relative frequency, velocity and synchronization index. It was observed that more negative osmotic potential caused significant reduction in crambe seed germination and vigor, and no normal seedlings was observed at potentials below -0.6 MPa.

Crescimento inicial do eucalipto em função da aclimatação em viveiro

This study aimed to evaluate the acclimatization effects in the Eucalyptus grandis vs. Eucalyptus urophylla seedlings nursery in their initial growth in two soils types, clay and sandy. The seedlings were planted in Plantmax substrate and in rice hulls plus vermiculite, and managed, after 60 days of the mass propagation (DAE), during the rustication. There were five different frequencies of subsurface drip irrigation, restoring the soil field capacity condition: F1, F2, F3 and F4, which were irrigated once, twice, three and four times a day, respectively, and FD, kept in continue irrigation until planting at 90 DAE. In a randomized block design with four replications, plant height (HPA) were evaluated at 6 and 13 months after planting and the diameter at breast height (DAP) at 13 months after planting. Findings show that water management at hardening phase seedlings had no influence on growth in both soils.

Supressão de água em diferentes fases fenológicas do feijoeiro (Phaseolus vulgaris L.)

Bean (Phaseolus vulgaris L.) is widespread in the Brazilian social and economic scene. The hypothesis is that if the water supply is suppressed in just one of the five development stages of irrigated beans, it can result in yield reduction lower than 20%, allowing water economy. The objective of this study was to compare the performance of bean Carioca group IAC Alvorada yield components, with irrigation suppression in each of the five phenological phases (emergence, vegetative, flowering, grain filling and maturation) and no irrigation and irrigated in all stages. The study was conducted at Agronomical Sciences College, UNESP, Botucatu, SP, Brazil. The statistical design was the randomized block with seven treatments and four replications. Data were subjected to analysis of variance and t test at 5% probability. A rainfall event (58 mm) after planting allowed the successful emergence of seedling beans in plots where water would not be applied. The yield components were higher affect when there was irrigation's suppression at Vegetative phase and at Flowering phase. The treatments where occurred irrigation suppression at Maturation and at Emergence showed yield reduction of less than 20%, proving the hypothesis.

Estimativas de parâmetros genéticos para caracteres quantitativos em progênies de polinização aberta de Eucalyptus urophylla

Eucalyptus urophylla S. T. Blake is outstanding for valuable wood production potential, adaptation plasticity for different environmental conditions, and for tolerance to canker. However, genetic improvement of this specie in Brazil depends on the existence of genetic variability in the introduced populations. The objective of this study was to investigate the genetic variation and gains in quantitative traits in a population established in 1992 in Selvíria - MS. The progeny trial was established in a partially balanced, 8 x 8 lattice design, with 64 families, collected at Anhembi Experimental Station (IPEF/ESALQ/USP). Each plot was made up of eight trees planted in a 3 × 3 m spacing. Significant among families genetic variations were observed in diameter at breast height (DBH), bark type, stem form, and survival. Estimates of average family heritability were high for all traits, ranging from 0.50 to 0.85. The simulated selection by using multi-effect index showed that under a varying number of plants per family. This method is the most indicated to maximize genetic gains (7.24%) and the effective population size (69.3). These results are a useful support for the transformation of this test into a seedling seed orchard and to become a source of vegetative material to build a clonal seed orchard.

Níveis de fertirrigação na avaliação das características morfofisiológicas em mudas de pimenta malagueta

O presente trabalho teve o objetivo de avaliar as características morfofisiológicas de mudas de pimenta malagueta (Capsicum frutescens) sob diferentes níveis de fertirrigação, utilizando-se fertilizante líquido 10-10-10 (N-P-K). O experimento foi realizado na Faculdade de Ciências Agrárias da Universidade Federal da Grande Dourados. O delineamento experimental foi em blocos casualizados (DBC), com seis doses de fertilizante líquido (0; 2,5; 5,0; 10,0; 20,0 e 40 mL L-1) diluídos na água de irrigação e quatro repetições. As mudas foram produzidas em viveiro telado, em bandejas de 128 células preenchidas com substrato. Realizou-se uma fertirrigação, aos 15 dias após a semeadura ( DAS). Avaliou-se, aos 30 dias após a semeadura, o número de folhas, o comprimento da parte aérea e da raiz, a massa fresca e seca da parte aérea e da raiz, a área foliar e o teor de clorofila. A dose de 25 mL L-1 do fertilizante líquido 10-10-10, aplicada via fertirrigação, é recomendada para a produção de mudas de pimenta malagueta, embora tenha havido aumento da massa seca de raízes e parte aérea em dose maior.

Corn yield with reduction of insecticidal sprayings against fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae)

The ideal time is more important than amount of insecticidal spraying to adequate the control of Spodoptera frugiperda J.E. Smith (Lepidoptera: Noctuidae) in corn. This study aimed to evaluate lufenuron sequential sprayings effect and its rotation with other active ingredients on the population, damage caused by S. frugiperda and the impact on corn yield. The experiment was carried out in the field with six treatments: (1) one lufenuron spraying, (2) two lufenuron sprayings, (3) three lufenuron sprayings (4) four lufenuron sprayings, (5) sprayings with spinosad, lufenuron, thiamethoxam+lambdacyhalothrin and deltamethrin (in sequence, at ten days intervals) (6) control treatment. Sprayings started twenty days after the seedling had emerged and then every ten days for a maximum of four sprays. Both caterpillar population (20.9-21.7 larvae/plot) and index of damage (1.2-1.7) observed in corn plants were significantly lower in treated plots compared to control (untreated) (31.7 larvae/plot and index of damage 2.7), regardless of spraying amount. The results showed that multiple insecticide applications to control S. frugiperda do not guarantee higher yields in corn, ranging from 6375.2 to 7650.1 kg ha -1. Only one spraying of lufenuron was enough to prevent significant reduction in corn yield (6749.9 kg ha -1). © 2012 Asian Network for Scientific Information.

Formas de ureia e doses de nitrogênio em cobertura na qualidade fisiológica de sementes de trigo

Besides increasing productivity, nitrogen fertilization may have positives effects on seed physiological quality. The objective of this study was to evaluate the effect of different forms and levels of urea in top dressing fertilization on the physiological quality of wheat seed genotypes. Seeds of three wheat genotypes (BRS 208, BRS Pardela and IWT 04008) were evaluated for four levels of nitrogen fertilization (0, 40, 80 and 120 kg.ha-1) in three forms of urea (conventional urea, urea with urease inhibitor and protected urea). The nitrogen fertilization was applied during tillering, 20 days after emergence. The seed nitrogen content, 1000 seed mass, germination and vigor (germination first count, cold test, seedling emergence in the field, dry weight of seedlings, accelerated aging and electrical conductivity) were evaluated. The IWT 04008 line and the cultivar BRS Pardela had seeds with a higher physiological quality than those of the cultivar BRS 208. The forms of urea and levels of nitrogen in topdressing did not affect seed physiological quality of the different wheat genotypes.

Crescimento de mudas de Schizolobium amazonicum (Huber ex Ducke) em substrato fertilizado com nitrogênio, fósforo e potássio

The nutritional management of seedlings in the nursery is one of the most important practices that influence seedling quality. The aim of this work was to evaluate the effect of nitrogen, phosphorus and potassium on the development of Schizolobium amazonicum seedlings grown in 250 cm containers with a commercial substrate in the North of Mato Grosso State, Brazil. The experimental design was completely randomized design with five treatments and five replications, each replication being represented by 24 seedlings. The treatments were: control (only commercial substrate); nitrogen fertilization (150 g m-3 N using ammonium sulfate + 1.0 kg of ammonium sulfate dissolved in 100 L of water and applied in coverage); phosphorus fertilization (300 g P2O 5 m-3 using simple superphosphate); potassium fertilization (100 g m-3 K2O using potassium chloride + 0.3 kg of potassium chloride dissolved in 100 L of water and applied in coverage) and; complete (a mixture of the three nutrients, 150, 300 and 100 g m-3 N, P2O5 and K2O, respectively + 1.0 kg of ammonium sulfate + 0.3 kg of potassium chloride). The commercial substrate was composted milled pine bark plus vermiculite. Evaluations of the seedlings were performed at 90 days after sowing. The complete treatment (NPK) gave the highest values for biometric and best plant indices, which express the quality. When analyzing nutrients in isolation; potassium had the lowest effect. Based on these results it can be recommended to fertilize Schizolobium amazonicum seedlings in nurseries with 150, 300 and 100 g m-3 of N, P2O5 and K2O, respectively, plus 1.0 kg of sulfate ammonium and 0.3 kg of potassium chloride applied in coverage.