Emergence of coffee berry borer, Hypothenemus hampei (Ferrari), from infested coffee berries (Coffea arabica) was studied in the laboratory under controlled temperature and relative humidity (RH) regimes. Low humidities (<60% RH, 25°C) provoked rapid evacuation of adults. Emergence was at a minimum at 90% RH. A steady increase in emergence occurred at values from 90 to 100% RH. Emergence was low below 20°C (90 and 100% RH) and increased markedly between 20 and 25°C. There was no significant increase in emergence above 25°C. Using a simple flight event recorder, emergence flight times were found to peak at the time of maximum daily ambient temperatures on successive days. Under constant temperature conditions successive peaks of emergence were not seen. Results are discussed in relation to control and sampling procedures.

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SUMMARYIn view of the importance of the macroporosity for the water transport properties of soils, its quantitative assessment is a challenging task. Measurements of hydraulic conductivity (K) at different soil water tensions and the quantification of water-conducting macropores ( M ) of a soil under different tillage systems could help understand the effects on the soil porous system and related hydraulic properties. The purpose of this study was to assess the effects of Conventional Tillage (CT), Chisel Plow (CP) and No Tillage (NT) on M and on K; and to quantify the contribution of macroporosity to total water flux in a loam soil. A tension disc infiltrometer was used at two soil water pressure heads (-5 cm, and 0) to infer M and K, during fallow. Macroporosity was determined based on the flow contribution between 0 and -5 cm water potentials (K 0 , K 5 , respectively), according to the HagenPoiseuille equation. The K 0 values were statistically higher for CT than for NT and CP. The K 5 values did not differ statistically among treatments. The mean K values varied between 0.20 and 3.70 cm/h. For CT, M was significantly greater than for CP a nd N T, follo wi ng t he s am e trend as K 0 . No differences in M were detected between CP and NT. With CT, the formation of water-conducting macropores with persi stenc e unti l p ost -ha rv est wa s p oss ible, while under C P p rep ara tio n, the w aterconducting macropores were not persistent. These results support the idea that tillage affects the soil water movement mainly by the resulting water-conducting macropores. Future studies on tillage effects on water movement should focus on macroporosity.Index terms: Tension disc infiltrometer, no tillage, chisel plow, conventional tillage, effective porosity.(

Mortality of the coffee berry borer was studied under controlled laboratory conditions in Tapachula, Mexico. For adult female borers subjected to a range of relative humidities (RH) without food at 25°C, the longest mean survival time (20 days) was obtained at 93.5% RH. Adult borer survival was also studied at a range of temperatures for a fixed relative humidity (93.5% RH); at 20°C mean survival time was 28 days. Fecundity and mortality of borer stages in berries was studied for a range of humidities at 25°C. Maximum fecundity was obtained at 90 and 93.5% RH. Immature stages were ejected from the berry at 84% RH and above, which is interpreted as a form of brood hygiene.

Crop-livestock systems under no till (NT) could negatively affect soil physical properties and crop performance, due to the additive effects of reduced soil cover and cattle trampling due to livestock grazing, and the absence of tillage. We evaluated the effects of four grazing strategies and of a shallow tillage (ST) on soil physical properties and corn (Zea mays L.) performance for a mollisol after 15 years under crop-livestock systems under NT in Argentina. Grazing strategies evaluated were: closure (C), one grazing (OG), high stocking rate (HR) and farmer's management (FM), and the tillage systems were: NT and ST. Bulk density (BD), penetration resistance (PR), hydraulic conductivity (k s ), plant population, surface root distribution, aboveground dry matter accumulation, aboveground total N (TN) accumulation and corn yield were evaluated. High stocking rate and FM increased RP. On the other hand, ST decreased PR and BD and increased k s . Corn yield was higher under ST than under NT, and under HR than under the other grazing strategies. Total N accumulation was higher under HR than under the rest of grazing strategies. Rational grazing management and use of tillage systems on resilient soils could have prevented soil physical properties be affected beyond critical thresholds.

Se realizaron ensayos en campo con el objeto de evaluar los efectos y la persistencia de la compactación inducida por diferentes intensidades de tránsito durante la cosecha forestal en una población de álamos (Populus sp.). Se trabajó con un tractor de tracción simple de 73,5 kW y un acoplado, con una masa de 4,2 Mg y 2,7 Mg, respectivamente. Se establecieron 3 tratamientos de tránsito: 1, 5 y 10 pasajes sobre una misma senda, contrastados con un testigo sin tránsito. Luego de cada tratamiento, y 3 años después de realizados los mismos, se efectuaron determinaciones de penetrometría, densidad aparente y humedad gravimétrica. Hubo incrementos significativos de resistencia a la penetración para los tratamientos con tránsito, alcanzando el de mayor intensidad valores entre el 76 y el 16 % en los primeros 40 cm de profundidad. La densidad aparente tuvo una tendencia similar limitada a una menor profundidad. Luego de 3 años, los efectos persistían a nivel subsuperficial, para el índice de cono en los sectores tránsitados con respecto a los no transitados, encontrándose diferencias significativas para el tratamiento de 10 pasajes respecto al de 1 pasaje hasta 50 cm. Aún con cargas por eje de 3 Mg, el incremento de la intensidad de tránsito induce compactación a nivel subsuperficial que persiste en el tiempo.