Etiology and varietal response of Egyptian cotton to boll rot diseases [electronic resource].

Includes references.

Two field experiments were canied out at Sakha Agriculture Research Station during two successive seasons (2000 and 2001) to study the susceptibility of nine Egyptian-cotton varities to cotton boll rots; five of them belong to the extra-long staple category i.e. Giza 45, Giza 70, Giza 87, Giza 88 and Giza 84 (G. 74 x G. 68), and four belong to the long staple category i.e. Giza 85, Giza 86, Giza 89 and hybrid Giza 89 x Giza 86. This study revealed that: 1- Over the two growing seasons Giza 45 was the most susceptible variety, it exhibited 38.38% disease incidence, while, Giza 70 exhibited resistant reaction (10.06%) for the extra-long staple category, when Giza 89 recorded 35.70% disease incidence while Giza 85 had the lowest disease incidence (22.31%) for the long staple category. Data revealed that the first season recorded low average (17.09%), while, the second one had high average (33.15%). 2- Nine boll rot diseases were identified from the diseased bolls. Phytophthora and Fusarium boll rots had the highest frequency through the two (38.01% and 26.25%, respectively).

Summary in Arabic.

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