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The direct seeds sowing reduces the costs of implanting of forest stand, but it is necessary to study the ideal sowing depth, since this factor can affect the emergence and initial growth of the seedlings. The aim of this study was to evaluate the influence of different sowing depths on emergence, survival, and initial growth of Schizolobium parahyba var. amazonicum in the field conditions. A randomized block design was adopted, with five treatments and five replications, of 20 seeds each. The treatments were different depth, as follows: 5 cm (T1), 10 cm (T2), 15 cm (T3), and 20 cm (T4). Were evaluated the percentage of emergence, average time and emergence speed index, collar diameter, number of leaves, aerial part height, degree of slenderness and survival rate of seedling at 120 days after sowing. The results showed that emergence started two days after sowing, stabilizing on the 13th day. The depths of 5, 10, and 15 cm showed satisfactory results in terms of emergence percentage, survival rate and initial growth. The sowing depth of 10 cm was the best results for the variables studied. The best result for the average time and emergence speed index were obtained at depth of 5 cm. Direct sowing of S. parahyba is a viable method to be implemented by small and medium farmers, aiming to reduce costs by eliminating the nursery phase. The ideal seeding depth for the emergence, survival and initial growth of S. parahyba is at a depth of 10 cm. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Agricultural Sciences / Revista Brasileira de Ciências Agrárias is the property of Universidade Federal Rural de Pernambuco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Oil palm (Elaeis guineensis Jacq.) is an African palm that is distinguished by its elevated oil production per unit area, however, fitossanitary problems are one of its the main drawbacks. Thus, this study aimed to evaluate the spatial distribution pattern of the Rhynchophorus palmarum (L) (Coleoptera: Curculionidae) in oil palm plantations with geo-statistical procedures in the south of the state of Roraima, Brazil. The 25 ha of experimental area is located in the municilaity of São João da Baliza, RR, where 24 samples were carried out in the period from September 2013 to August 2014. For the insects collection, a buckettype trap with food attractant (sugarcane) was placed in each one of the 100 sampling points. Analyses of spatial variability and spatial dependence were held by the incorporation of geo-statistical procedures based on spatial modeling techniques by semivariagrams. The spatial distribution of the R. palmarum is aggregated with spatial dependence described by the spherical model, forming clusters of 100 to 210 m radius. It was observed that R. palmarum infestation takes place both in the center just as on the edges of the plantation, with later dissemination to the entire area. The maximum range found in the study was of 210 m, with an area of influence of 13.9 ha. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Agricultural Sciences / Revista Brasileira de Ciências Agrárias is the property of Universidade Federal Rural de Pernambuco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)