الفهرس Only 14 pages are availabe for public view
 |  | from | 383 |  |  |
| | | from | 383 | | |
Abstract
1- Percentages of natural infection and severity of strawberry fruit rots were higher than those of flower blight during diseases survey in 2002/2003 season. These percentages, however, increased from the 1st fruiting cycle to the 3rd one. Kalubyia governorate showed the highest mean percentages which recorded (19.00 % & 16.10 %) and (12.08 % & 8.26 %) for the two diseases, respectively. In contrast, the lowest ones of (11.08 % & 7.70 %) and (6.50 % & 4.05 %) were , respectively, obtained in Sharkyia governorate.
2- Eight fungal genera were isolated from rotted fruits and blighted flowers collected from the five inspected governorates. They are; Alternaria, Botrytis, Cladosporium, Fusarium, Helminthosporium, Phytophthora, Rhizopus and Rhizoctonia. Five of these genera were identified to their species as : Alternaria alternate (Fr.) Keissler, Botrytis cinerea Pers., Phytophthora cactorum (Lebert & C?hn) J. Schrot, Rhizopus nigricans Ehrenb., Rhizoctonia fragariae Hussain & W.E. McKeen and Rhizoctonia solani Kühn.
3- All fungi were isolated from infected flowers with different frequencies. R. solani (16.42-21.80%) was the most frequently isolated fungi followed by B. cinerea (15.62-17.76 %), whereas Cladosporium sp. (6.95-8.41 %) recorded the lowest percentage of occurrence.
4- Botrytis cinerea followed by R. solani were isolated more frequently from rotted fruits (17.65-20.75 %) and (14.78-16.93%) during diseases survey in2002/2003 season, respectively. Rhizopus nigricans, contrarily, recorded the lowest percentages of frequency by (5.31-7.58 %).
5- All fungi tested could induce flower blight symptoms under greenhouse conditions with positive relationship, between plant age and percentages of infection and severity during the three fruiting cycles. R. solani followed by B. cinerea were the most pathogenic fungi recording percentages of infection and severity by (13.75-35.63 %) and (11.25-21.25 %) as well as (9.26-25.10 %) and (7.79-17.89 %) for the two measurements, respectively. All fungi isolated from blighted flowers were more pathogenic than those isolated from rotted fruits.