An-Najah Staff

Samples of grape leaves and berries (CV: Zeini) were taken from grape-vine yards treated with chlorpyrifos (Dursban?) and penconazole (Ofir?) in order to determine their residues in these organs. The effect of time after spraying and number of sprays on the residues of both pesticides was studied. Gas chromatorgraphy /mass spectrometry (GC/MS) was used to determine the residue levels. Results obtained have indicated the presence of both pesticides in the tested leaf samples, but chlorpyrifos residues were detected in larger quantities than penconazole residues. Also, larger quantities of both pesticides were detected in the samples of berry cortex than in the samples of berry flesh. However, the residues of both pesticides in washing water of treated berries were lower than that in the cortex or in the flesh. This may indicate the systemic action of esticides especially penconazole, since washing the treated berries with water two weeks after application of the last spray did not remove the pesticides from berries. Overall results have indicated that the determined quantities of both pesticides residues especially in the cortical tissues of treated berries following the sixth application of both pesticides were higher than the quantities reported by other authors in grape berries, but they were generally less than the maximum residue limits (MRLS) defined by the residue legislations in other countries.

Samples of grape leaves and berries (CV: Zeini) were taken from grape-vine yards treated withchlorpyrifos (Dursban®) and penconazole (Ofir®) in order to determine their residues in these organs. Theeffect of time after spraying and number of sprays on the residues of both pesticides was studied.Gaschromatorgraphy Imass spectrometry (GCIMS) was used to determine the residue levels. Results obtained haveindicated the presence of both pesticides in the tested leaf samples, but chlorpyrifos residues were detectedin larger quantities than penconazole residues. Also, larger quantities of both pesticides were detected in thesamples of berry cortex than in the samples of berry flesh. However, the residues of both pesticides in washingwater of treated berries were lower than that in the cortex or in the flesh. This may indicate the systemic actionof pesticides especially penconazole, since washing the treated berries with water two weeks after applicationof the last spray did not remove the pesticides from berries. Overall results have indicated that the determined quantities of both pesticides residues especially in the cortical tissues of treated berries following the sixth application of both pesticides were higher than the quantities reported by other authors in grape berries, but they were generally less than the maximum residue limits (MRLS) defined by the residue legislations in other countries.

• The present research deals with the effect of postharvest treatment of grape berries with four commonly used fungicides and two forms of Trichoderma harzianum on the infection with soft-rot fungi- Rhizopus stolonifer and Mucor piriformis. This effect was evaluated by comparison of the external diameter of rot-lesion in treated and untreated berries, in addition to comparison of percent reduction in external rot-lesion diameter relative to control. Results indicated that the infection with R. stolonifer and M. piriformis was significantly reduced (P<0.05) in all treated berries in comparison with untreated control berries. The highest reduction in mean external rot-lesion diameter was obtained for both R. stolonifer and M. piriformis when inoculated berries were treated with Score® (difenoconazole) applied at 0.35%(v/v) or Switch® (cyprodinil + flodioxonil) applied at 0.20%(w/v) or formulated T. harzianum conidia in invert emulsion applied at 9.6x108 conidia/ml of formulation (13.5, 13.2, and 19.3 mm, respectively for R. stolonifer; 7.2, 7.5, and 19.2mm, respectively for M. piriformis). The greatest decrease in percent reduction in external rot-lesion diameter relative to control was also obtained for both the fungal species when inoculated berries were treated with the same type of fungicides (Score® and Switch®) and Trichoderma (formulated T. harzianum in invert emulsion) (60.9, 61.7, and 44.1%, respectively for R. stolonifer; 74.5, 73.4, and 31.9%, respectively for M. piriformis). Overall results indicate that the most effective treatment obtained on grape berries could be integrated with other control measures being usually used in grape berry-rot management plans by alternating fungicidal treatment (e.g. Score® or Switch®) with application of formulated T. harzianum conidia in invert emulsion.