Table 3.

Effect of silver nanoparticles synthesized by extracellular agents of Bacillus pumilus, B. persicus, and B. licheniformis on virus concentration, percentage of infection and disease severity (DS) of fava bean, cv. Giza3 infected by Bean yellow mosaic virus under greenhouse conditions.

Treatment	Virus concentration by DAS-ELIZA Group			Infection (%) Group			DS (%) Group
	I	II	III	I	II	III	I	II	III
No treatment	1.744	1.431	1.150	100	100	100	100	100	100
NPs-1	0.411	1.199	0.095	0	100	0	0	75	0
NPs-2	0.532	1.288	0.415	89	100	34	44	100	8
NPs-3	0.400	1.112	0.091	0	100	0	0	50	0

Group I: plants treated with silver nanoparticles simultaneously with BYMV infection; Group II: plants treated with silver nanoparticles before virus infection; Group III: plants treated with silver nanoparticles after virus infection. For details see text. The values are means of three determinations; In Elisa test the positive (infected leaves with symptoms) and the negative (infected leaves without symptoms) controls are 1.492 and 0.113, respectively.