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Field experiments were conducted in southwest Spain for three consecutive years from 2000 to 2003 to evaluate the effectiveness of solarization and Trichoderma spp., alone and combined, in reducing Phytophthora cactorum soil populations and consequently leather rot on fruit of strawberry plants. Plots (12.5 by 3.3 m), never treated with methyl bromide, were naturally infested by P. cactorum. Solarization was conducted during the summer, using clear 50-μm low-density polyethylene mulch. Trichoderma spp. were applied via drip and dip, adding to the soil 7 days before planting (108 conidia/m²), and strawberry roots were dipped in a suspension of Trichoderma spp. (106 conidia/ml) prior to planting. Solarization reduced the soil P. cactorum population 100% in year 1, 47% in year 2, and 55% in year 3 relative to the untreated control. Trichoderma spp. applications reduced soil populations of P. cactorum and reduced leather rot incidence 76.6% in year 1 and 33.8% in year 2 compared with the untreated control. The combination of solarization and Trichoderma spp. reduced P. cactorum soil population the most each year, 88.9% in January 2001, 97.6% in 2002, and 99.0% in 2003. The very promising effect of Trichoderma spp. and solarization against P cactorum indicates that there may be future alternatives to traditional chemicals for disease control. [ABSTRACT FROM AUTHOR]

Several preplant soil fumigation treatments were repeated over a period of three years on strawberry (Fragaria xananassa Duchesne) crops, at two different places in the province of Huelva (southwestern Spain). The influence of these treatments on Trichoderma soil populations and on populations of soilborne pathogens was examined every year by isolating soil onto selective media. No strawberry pathogens were detected but Trichoderma soil populations increased each year after the treatment. Significant differences were noted between the treatments and also compared to the control. The largest populations were observed after treatments with methyl bromide and chloropicrin, and so resulting in a higher production. Chemical name used: trichloronitromethane (chloropicrin). [ABSTRACT FROM AUTHOR]

Introduction The development of medical imaging, and more specifically functional imaging, open new perspectives for radiotherapy treatments. The joint use of the dosimetric CT and the PET improve the determination of target volume by combining functional and morphological data. The purpose of this study is to evaluate the recovery process of the PET contours for respiratory-gated radiotherapy according to two methods: the Replanning algorithm (RP) and the module Integrated Registration (IR) from General Electric (GE) Medical System. Methods The 4D acquisitions are achieved on a dosimetric CT Brillance Big Bore® (Philips Medical System) associated to an abdominal belt Pneumo chest Bellows (Lafayette Instrument) and on a PET/CT Discovery 710 (GE Medical System) coupled to the respiratory gating system RPM (Real-Time Position Management™, Varian Medical System). The Quasar™ Programmable Respiratory Motion Phantom (Modus Medical Device Inc) is used with a lung density insert. The lesions are simulated by solid spheres of 1 and 3 cm diameter and another empty one of 2 cm. The acquisitions have been performed with breathing amplitude of 2 and 4 cm and breathing frequency of 10, 15 and 20 bpm. The influence of the acquisition parameters, reconstruction parameters and variability of the patient parameters (amplitude, frequency, lesion size) are being assessed. On the CT images, the spheres are segmented with a threshold allowing to obtain theoretical volume of the sphere on a 3D acquisition. On the PET images, the spheres are segmented with a 42% threshold of the SUVmax. The PET/CT contours obtained with the RP algorithm and the IR module have been compared to the contours delineated on the dosimetric CT with Eclipse v13.5, using the Dice’s coefficient. Results The influence of the acquisition and reconstruction parameters studied with the RP algorithm show Dice’s coefficients ranging from 0.93 to 0.96. Dice’s coefficients variating between 0.85 and 0.94 are obtained for the study of variability of patients parameters. With regard to the two retrieval methods of PET contours, they show similar Dice’s coefficients. For an amplitude of 2 cm and a respiratory frequency of 15 bpm, the Dice’s coefficient is 0.84 with RP algorithm and 0.85 with the IR method. Conclusions For pulmonary lesions, the two retrieval methods of RP or IR contours appear similar. In the field of radiotherapy, a new way to use the replanning algorithm seems possible and allows for the simplification of the recovery of the PET contours. A clinical study is in the process of being evaluated. The objective is to validate this method in lung lesions cases. [ABSTRACT FROM AUTHOR]

Atmospheric concentrations of Sphaerotheca macularis conidia were monitored for 2 years on a strawberry crop in Huelva (southwestern Spain). The presence of airborne conidia was determined to assess the role of weather conditions on conidial release. The relationship between airborne conidia and incidence of powdery mildew on fruit was also studied. Concentrations of conidia were estimated with a Burkard volumetric spore sampler. The presence of conidia was related to temperature, relative humidity, and rainfall, with a positive correlation for the first factor and a negative correlation with the other two. The presence of conidia in the air was positively correlated with disease incidence. A diurnal pattern of conidia release was observed. [ABSTRACT FROM AUTHOR]