Early-season predation on aphids by winter-active spiders in apple orchards revealed by diagnostic PCR

Aphids are major pests in apple orchards, debilitating the crop and spreading disease. We investigated whether early-season predation by canopy spiders may be effectively controlling aphid numbers in three organic orchards. For this purpose, we monitored the aphid population dynamics from the winter eggs to colony stages and compared this to spider abundances and rates of predation on aphids detected by diagnostic polymerase chain reaction. For the latter, we applied existing general aphid primers. We found that spiders ate colony fundatrices and that aphid numbers were negatively related to spider abundance. Spiders were the main active predators within the orchards when the first colony fundatrices were present, indicating their importance in the early control of aphid populations

Control of post-harvest brown rot on nectarine by Epicoccum nigrum and physico-chemical treatments

Post-harvest physico-chemical treatments - water at 40°C or 60°C (HW), and sodium bicarbonate at 1 or 2.5% (SBC) at 20, 40 and 60°C - were tested on peaches and nectarines in order to control brown rot caused by Monilinia spp.;to select the best physico-chemical treatment to be used in combination with pre-harvest applications of the biological control agent Epicoccum nigrum (ATCC number 96794). Experiments were carried out in France, Italy and Spain in order to test different experimental conditions. Monilinia rot was reduced in peach and nectarine treated with HW (40°C for 2 min) in all three countries, the percentage of rot reduction was similar for France, Italy and Spain (over 40%). A synergistic effect between HW at 40°C during 150 s or at 60°C during 20 s and SBC was observed in all three countries. After preliminary experiments post-harvest treatment of HW (60°C) + SBC (1%) during 20 s was selected to combine it with field treatments. Pre-harvest treatments with fungicide or E. nigrum did not reduce brown rot in any country. However, pre-harvest treatments with E. nigrum, chemical fungicide, and their integration followed by post-harvest physico-chemical treatment significantly reduced Monilinia rot compared to pre-harvest untreated fruits followed by post-harvest physico-chemical treatment in Italy (over 70%). Post-harvest treatments with E. nigrum were also tested in Italy on natural and artificial infections in nectarine over 3 years. E. nigrum, as fresh or formulated cells, at a concentration of 108 conidia mL-1 were effective, significantly reducing the incidence of brown rot compared to control, both under artificial and natural infection, from 43 to 100%. © 2007 Society of Chemical Industry

Biological control of postharvest brown rot (Monilinia spp.) of peaches by field applications of Epicoccum nigrum

Seven field experiments were carried out in peach orchards located in Spain, Italy, and France in 2001 and 2002 to develop an effective and practical method of controlling brown rot disease caused by Monilinia spp. by pre-harvest applications of Epicoccum nigrum treatments. Three trees (100 fruits), randomly selected in each orchard, were used as the sample unit and every treatment was repeated four times. Factors considered in each orchard and year to compare E. nigrum and/or fungicide pre-harvest application were the time of application, fresh or formulated cells, and dose. Fresh or formulated cells (10 6-7 conidia ml -1) of E. nigrum need to be applied twice both at bloom and preharvest to reduce postharvest brown rot. Chemical fungicides reduced disease in French and Italian trials but not in a Spanish trial. Integrated control (biological and chemical) was efficient in controlling the pathogens. E. nigrum application, alone (applied 4 times) or in combination with fungicides can be considered in a disease control strategy for reducing fungicide treatments and residues. A further reduction of brown rot may be possible by a better formulation of the biological product and postharvest combined treatments. © 2004 Elsevier Inc. All rights reserved

Effect of plasma shape on confinement and MHD behaviour in TCV

The TCV tokamak (B-T 0. The main change in MHD behaviour when elongation is increased beyond two is an increase in the relative importance of modes with m, n < 1 and a reduction of sawtooth amplitudes. Confinement is strongly dependent on plasma shape. In ohmic limiter L-modes energy confinement times improve typically by a factor of two as the plasma triangularity is reduced from 0.5 to 0 at constant q(a). There is also an improvement of confinement as the elongation is increased. In most discharges the changes in confinement are explained by a combination of geometrical effects and power degradation. A global factor of merit H-s (shape enhancement factor) has been introduced to quantify the effect of Bur surface geometry. The introduction of H-s into well known confinement scaling expressions such as Neo-Alcator and Rebut-Lallia-Watkins scaling leads to improved descriptions of the effect of shape for a given confinement mode. In some cases with kappa(a) greater than or equal to 1.7 limited ohmic L-modes undergo a slow transition to a confinement regime with an energy confinement improved by a factor of up to 1.5 and higher particle confinement. First experiments to study the effect of shape in ECRH at a frequency of 83 GHz (second harmonic) have been undertaken with 500 kW of additional power

Steady-state fully noninductive current driven by electron cyclotron waves in a magnetically confined plasma

A steady-state, fully noninductive plasma current has been sustained for the first time in a tokamak using electron cyclotron current drive only. In this discharge, 123 kA of current have been sustained for the entire gyrotron pulse duration of 2 s. Careful distribution across the plasma miner radius of the power deposited from three 0.5-MW gyrotrons was essential for reaching steady-state conditions. With central current drive, up to 153 kA of current have been fully replaced transiently for 100 ms. The noninductive scenario is confirmed by the ability to recharge the Ohmic transformer The dependence of the current drive efficiency on the minor radius is also demonstrated

Effect of plasma shape on confinement and MHD behaviour in TCV

The TCV tokamak (B-T 0. The main change in MHD behaviour when elongation is increased beyond two is an increase in the relative importance of modes with m, n < 1 and a reduction of sawtooth amplitudes. Confinement is strongly dependent on plasma shape. In ohmic limiter L-modes energy confinement times improve typically by a factor of two as the plasma triangularity is reduced from 0.5 to 0 at constant q(a). There is also an improvement of confinement as the elongation is increased. In most discharges the changes in confinement are explained by a combination of geometrical effects and power degradation. A global factor of merit H-s (shape enhancement factor) has been introduced to quantify the effect of Bur surface geometry. The introduction of H-s into well known confinement scaling expressions such as Neo-Alcator and Rebut-Lallia-Watkins scaling leads to improved descriptions of the effect of shape for a given confinement mode. In some cases with kappa(a) greater than or equal to 1.7 limited ohmic L-modes undergo a slow transition to a confinement regime with an energy confinement improved by a factor of up to 1.5 and higher particle confinement. First experiments to study the effect of shape in ECRH at a frequency of 83 GHz (second harmonic) have been undertaken with 500 kW of additional power