Resource partitioning among epigaeic and hypogaeic ants (Hymenoptera: Formicidae) of a Brazilian cocoa plantation

Patterns of dietary and foraging strata utilization by the ground ant community of a Brazilian cocoa planatation were examined using sugar, meat and flour baits on the surface as well as buried. A total of 49 ant species was recorded, including 10 species of Pheidole. Strong dominance was exercised by Solenopsis geminata at both surface and subterranean strata, and at all food resources. The dissimilarity matrix of the epigaeic ant fauna was much greater than that for the hypogaeic species. At least four guilds were identified: the fungus-growing ants, epigaeic nectivores, epigaeic carnivores, and hypogaeic foragers. Niche breadth reduction, leading to the formation of guilds, permits the coexistence of many species in the this ground ant community from a tropical cocoa plantation. -Authors

ANT (HYM, FORMICIDAE) MOSAIC STABILITY IN BAHIAN COCOA PLANTATIONS - IMPLICATIONS FOR MANAGEMENT

Mapping and collection of ants in cocoa trees in a 1 ha plot in the south of Bahia, Brazil, revealed three dominant species of the ant mosaic: Wasmannia auropunctata, Ectatomma tuberculatum and Azteca chartifex spiriti. A. chartifex demonstrated a larger influence in the cocoa plantation due to its spatial and temporal (1 y) stability in the same cocoa trees, and its capacity for territorial expansion. The management of A. chartifex for controlling insect pests of cocoa is strongly recommended. Considerations of temporal permanence of mosaic dominant ants should be a necessary criteria for ant management in tropical tree crops.

Space dependency of chemical attributes in an area with sugarcane plantation in Pereira Barreto, SP

The behavior of the chemical attributes is directly influenced by superficial flow and water movement inside the soil. This work aimed to study the space dependency of chemical attributes in an area with sugarcane plantation in Pereira Barreto, SP. An area of 530.67 hectares was mapped using an equipment of Global Positioning System and obtaining a Digital Elevation Model. A set of 134 soil samples were collected every seven hectares in the depths of 0-0.25 m and 0.80-1.00 m. The pH, organic matter (OM), Ca, Mg, K, BS, CEC and base saturation (BS) were analyzed. All the chemical attributes presented similar behavior in the superficial and subsuperficial layer of the soil, which provided better visualization and definition of the homogeneous tillage zones.

Biomass and Stand Characteristics of a Highly Productive Mixed Douglas-Fir and Western Hemlock Plantation in Coastal Washington

Aboveground biomass predictive equations were developed for a highly productive 47-year-old mixed Douglas-fir and western hemlock stand in southwest Washington State to characterize the preharvest stand attributes for the Fall River Long-Term Site Productivity Study. The equations were developed using detailed biomass data taken from 31 Douglas-fir and 11 western hemlock trees within the original stand. The stand had an average of 615 live trees per hectare, with an average dbh of 35.6 cm (39.1 cm for Douglas-fir and 33.3 cm for western hemlock) and an average total tree height of 31.6 m (32.8 m for Douglas-fir and 30.2 m for western hemlock). Equations developed were of the form In Y = b(1) + b(2) In dbh, where Y = biomass in kg, dbh = diameter in cm at 1.3 m height, b(1) = intercept, and b(2) = slope of equation. Each tree part was estimated separately and also combined into total aboveground biomass. The total aboveground biomass estimation equations were In Y = -0.9950 + 2.0765 In dbh for Douglas-fir, and In Y = -1.6612 + 2.2321 In dbh for western hemlock. The estimate of the aboveground live-free biomass was of 395 Mg ha(-1) (235 Mg ha(-1) for Douglas-fir and 160 Mg ha(-1) for western hemlock), with 9.5, 29.3, 12.9, 308, and 32.7 Mg ha(-1) in the foliage, live branches, dead branches, stem wood, and stem hark, respectively. When compared with biomass estimates from six other studies, ranging in age from 22 to 110 years and from 96.3 to 636 Mg ha(-1), the biomass of the Fall River site was relatively high for its age, indicating very high productivity.

Distribution and importance of spiders inhabiting a Brazilian sugar cane plantation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nutrient cycling in a RRIM 600 clone rubber plantation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

USE OF FALLEN COCOA PODS BY ANTS (HYMENOPTERA, FORMICIDAE) IN SOUTHEASTERN BRAZIL

Fallen cocoa pods serve as nesting and foraging sites for litter and ground ants in southeastern Brazil. The distribution of the number of species per pod deviated significantly from a Poisson distribution, with a prevalence of one species per pod. Only 17 species of a much larger fauna were present in pods, with the dominant species being Gnamptogenys striatula, and Oligomyrmex sp. Colony populations for 13 species are given.

Wasmannia spp. (Hym., Formicidae) and insect damages to cocoa in Brazilian farms

Diagnostic insect damage to cocoa tree leaves and fruits were compared in situations with and without the presence of the little fire ants, Wasmannia auropunctata and the closely related and sympatric W. cf rochai. No significant differences in thrips, lepidopteran, or chrysomelid beetle damage to fruits, or to young and old leaves, were associated with these ants. However, significant increases of pseudococcids Planococcus citrii, associated with areas dominated by W. auropunctata, and to a lesser degree with W. cf rochai, were present. W. auropunctata has been reported to be a canopy mosaic dominant in cocoa farms, but the lack of reduced herbivore incidences and its lack of spatial permanence do not support favoring its populations for the management of phytophagous insect control.

Growth and yield analysis in different methods of beet (Cv. 'tall top early wonder') plantation

This objective of this study was to evaluate the effects of different methods of red beet seedling production and direct sowing on the development of the plant in field conditions. 'Tall Top Early Wonder' was used as the cultivar. The experimental design was a randomized blocks with 4 replications of each treatment: T1 - seedling produced in trays of 288 cells; T2 - 200 cells; T3 - 128 cells; T4 - 128 cells; T5 - direct sowing and T6 - bare-root seedling. The seedlings produced in trays and bare root seedlings were transplanted in the field 28 DAS with spacing of 0.20 x 0.10m. The mean height of plants, leaf area, leaf dry matter, petiole dry matter, shoot dry matter, root dry matter, relationship between shoot dry matter and root dry matter, absolute growth rate, relative growth rate, net assimilation rate, leaf area ratio and specific leaf area were determined. Storage root fresh matter and mean storage root diameter were determined starting from 77 DAS. Initial growth of the plants were superior for the direct sowing, resulting in smaller RGR and NAR than the other treatments. Independent of the production method, an increase of the cycle of the crop was verified. T6 had larger delay in the initial development. There was no difference for productivity. Method T1, had less expenses with respect to substrate and space in the vegetation home, without reduction in production.

Impact of the timing and duration of weed control on the establishment of a rubber tree plantation

A produção da seringueira é reduzida pelas plantas daninhas que competem por recursos ambientais; portanto, a época e duração do controle de plantas daninhas influencia a interferência das plantas daninhas. Os objetivos deste estudo foram: avaliar o crescimento de plantas de seringueira (Hevea brasiliensis), determinar o período crítico para controle das plantas daninhas e avaliar a recuperação do crescimento das seringueiras que conviveram com plantas daninhas por diferentes períodos de tempo após o plantio. Dois grupos de tratamentos foram estabelecidos em condições de campo, no primeiro ano de investigação: um grupo conteve períodos crescentes de infestação de plantas daninhas, enquanto o outro conteve períodos crescentes de controle das plantas daninhas, também incluindo uma testemunha livre de plantas daninhas e uma testemunha com infestação total de plantas daninhas. No segundo ano da investigação, as plantas daninhas foram totalmente controladas. Urochloa decumbens foi a planta daninha dominante (mais de 90% de cobertura). O crescimento da cultura foi grandemente reduzido devido à interferência de plantas daninhas. A altura de plantas decresceu mais rapidamente que qualquer outra característica. Altura de planta, massa seca de folhas e área foliar decresceram em 99%, 97% e 96%, respectivamente, e foram as características mais reduzidas. A altura de plantas também se recuperou mais rapidamente que qualquer outra característica quando o período de controle das plantas daninhas foi entendido. Contudo, a massa seca do caule aumentou em 750%, fazendo desta a característica mais recuperada. O período crítico para o controle de plantas daninhas foi entre 4 e 9½ meses após o plantio, no primeiro ano; contudo, as seringueiras mostraram expressiva recuperação do crescimento quando as plantas daninhas foram controladas ao longo do segundo ano.

Influence of field slope and coffee plantation age on the physical properties of a red-yellow Latosol

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Atlantic rainforest remnant harbors greater biotic diversity but reduced lepidopteran populations compared to a eucalyptus plantation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mites from Cerrado fragments and adjacent soybean crops: does the native vegetation help or harm the plantation?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A Sampling Plan for Liriomyza huidobrensis (Diptera: Agromyzidae) on a Potato (Solanum tuberosum) Plantation

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)