Comparative studies on nanosulfur and certain fungicides to control cucumber powdery mildew disease and their residues in treated fruits

الملخص EN

The present work was carried out to explore the potential use of the new approach of sulfur nanoparticles compared with bulk sulfur and two other systemic fungicides to control powdery mildew in cucumber.

Also, the Fungicide residues in cucumber were estimated.

Examination of physico-chemical properties of the tested nanoparticles was done by using transmission electron microscope and X-Ray diffraction, which proved that the tested sulfur was sulfur (S₈) with the crystal system and its anorthic and size ranged from 12.2 to 23.5 nm.

The three tested fungicides, Super sardo (azoxystrobin), Muringo (diniconazole), Thiofan (bulk sulfur) and Nanosulfur (Snp) were sprayed three times to cucumber growing in pots in a greenhouse.

After 3^rd spray, the efficacy of the aforementioned tested fungicides was 74.0, 68.8, 42.7 and 60.9% , respectively.

The area under disease progress curve (AUDPC) in case of azoxystribin, bulk sulfur and Snp increased after 1^st and 2^nd sprays, but it decreased after 3^rd treatment.

diniconazole recorded continues increase in disease area.

Nanosulfur caused the highest number of fruits/plant, mean weight of fruits/plant and mean weight of one fruit and followed by azoxystribin and diniconazole, while bulk sulfur caused the lowest cucumber yield parameters.

Assessment of residues of the four tested fungicides 2, 5 and 8 days after the third spray, showed that cucumber fruits can be collected two days after treatment with azoxystribin, bulk sulfur and Nanosulfur, while those treated with diniconazole can be harvested five days after spray.