Seasonality of Tylenchulus semipenetrans Cobb and Pasteuria sp in citrus orchards in Spain

Population densities of the Mediterranean biotype of Tylenchulus semipenetrans were monitored in soil and citrus roots at 3-month intervals for 3 consecutive years in four citrus orchards in the provinces of Tarragona (Amposta and Xalamera) and Valencia (Moncada and Carcer). Nematode population densities in soil peaked once year in April or July depending on the orchard and year. Numbers of females per gram of root increased once or twice each year. The maximum density of eggs per gram of root was recorded in April at Xalamera and Carcer orchards, but there was no recognizable peak in the other two orchards. Numbers of nematodes in soil, females or eggs program of root, of eggs per female were correlated with either temperature or rainfall in the sampling month, 1 month before sampling, or in the second preceding month, depending on the orchard. Members of the Pasteuria group were present in the four citrus orchards, and a positive relationship occurred between nematodes in soil and bacterial parasitism (r(2) = 0.75) in the orchard at Amposta

Comparing different models of the development of verb inflection in early child Spanish

How children acquire knowledge of verb inflection is a long-standing question in language acquisition research. In the present study, we test the predictions of some current constructivist and generativist accounts of the development of verb inflection by focusing on data from two Spanish-speaking children between the ages of 2;0 and 2;6. The constructivist claim that children's early knowledge of verb inflection is only partially productive is tested by comparing the average number of different inflections per verb in matched samples of child and adult speech. The generativist claim that children's early use of verb inflection is essentially error-free is tested by investigating the rate at which the children made subjectverb agreement errors in different parts of the present tense paradigm. Our results show: 1) that, although even adults ' use of verb inflection in Spanish tends to look somewhat lexically restricted, both children's use of verb inflection was significantly less flexible than that of their caregivers, and 2) that, although the rate at which the two children produced subjectverb agreement errors in their speech was very low, this overall error rate hid a consistent pattern of error in which error rates were substantially higher in low frequency than in high frequency contexts, and substantially higher for low frequency than for high frequency verbs. These results undermine the claim that children's use of verb inflection is fully productive from the earliest observable stages, and are consistent with the constructivist claim that knowledge of verb inflection develops only gradually

Competition and habitat quality influence age and sex distribution in wintering rusty blackbirds.

Bird habitat quality is often inferred from species abundance measures during the breeding and non-breeding season and used for conservation management decisions. However, during the non-breeding season age and sex classes often occupy different habitats which suggest a need for more habitat-specific data. Rusty Blackbird (Euphagus carolinus) is a forested wetland specialist wintering in bottomland hardwood forests in the south-eastern U. S. and belongs to the most steeply declining songbirds in the U.S. Little information is available to support priority birds such as the Rusty Blackbird wintering in this threatened habitat. We assessed age and sex distribution and body condition of Rusty Blackbirds among the three major habitats used by this species in the Lower Mississippi Alluvial Valley and also measured food availability. Overall, pecan groves had the highest biomass mainly driven by the amount of nuts. Invertebrate biomass was highest in forests but contributed only a small percentage to overall biomass. Age and sex classes were unevenly distributed among habitats with adult males primarily occupying pecan groves containing the highest nut biomass, females being found in forests which had the lowest nut biomass and young males primarily staying in forest fragments along creeks which had intermediate nut biomass. Males were in better body condition than females and were in slightly better condition in pecan groves. The results suggest that adult males occupy the highest quality habitat and may competitively exclude the other age and sex classes

Problemes induïts per meloidogyne sp. a l'àrea de producció hortícola del litoral barceloní

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Species of Root-knot Nematodes and Fungal Egg Parasites Recovered from Vegetables in Almería and Barcelona, Spain

Intensive vegetable production areas were surveyed in the provinces of Almería (35 sites) and Barcelona (22 sites), Spain, to determine the incidence and identity of Meloidogyne spp. and of fungal parasites of nematode eggs. Two species of Meloidogyne were found in Almería—M. javanica (63% of the samples) and M. incognita (31%). Three species were found in Barcelona, including M. incognita (50%), M. javanica (36%), and M. arenaria (14%). Solanaceous crops supported larger (P < 0.05) nematode numbers than cucurbit crops in Almería but not in Barcelona. Fungal parasites were found in 37% and 45% of the sites in Almería and Barcelona, respectively, but percent parasitism was never greater than 5%. Nine fungal species were isolated from single eggs of the nematode. The fungi included Verticillium chlamydosporium, V. catenulatum, Fusarium oxysporum, F. solani, Fusarium spp., Acremonium strictum, Gliocladium roseum, Cylindrocarpon spp., Engiodontium album, and Dactylella oviparasitica. Two sterile fungi and five unidentified fungi also were isolated from Meloidogyne spp. eggs

Efecte de la solarització sobre la producció de patata de Prades (IGP) en un sòl infestat amb Globodera spp.

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Eficàcia de fumigants i nematicides pel control de Globodera spp. en conreu de patata a la serralada de Prades

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Eficàcia de fumigants i nematicides pel control de Globodera spp. en conreu de patata a la serralada de Prades

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