Monitoring the triangular relationship between maize, cotton and the infestation of the american bollworm (abw), helicoverpa armigera (hb.) and the spiny bollworm(sbw), earias insulana (BOISD.) [electronic resource].

Includes references.

Field trail were carried out to study the intercropping system effect between cotton, Gossypium spp., and maize, Zea mays L. known to attract moths and determine if the close plantings (= intercropping) they affecting the infestation figures of both, the american boIlworm (ABW), Helicoverpa armigera (Hb.) and the spiny bollworm (SBW), Earias insulana (Boisd.) in cotton fields during two successive cotton growing seasons 2000 and 2001 at El-Gemmeiza Agricultural Research Station, Gharbia governo¬rate and Aga district (private farm), Dakahlia governorate. The ABW infestation, started during June up to May in both years at each of Gemmeiza and Aga, respectively, while the SBW infestation observed during May at the two localities during the two growing seasons. Reliable infesta-tions by both 'insect pests were detected in maize field in July at both 2000 and 2001 at the two experimental maize growing areas. The highest infesta-tion expressed as percentage with ABW was 38.0 % recorded on cotton field at Aga during June 2001, while the lowest percentage was 0.4 % occurred in September 2000 and 2001 at Aga and Gemmeiza, respectively. The highest infestation (25.25 %) with SBW attacking maize was recorded during August 2001, while the lowest (0.25 %) was reached during July 2000 in cotton field at Aga district. The highest infestation with both worms was 13.48 % recorded in June and 9.80% in August at Aga and Gemmeiza, respectively, while the lowest was 0.64 % and 0.93 recorded in May at Gemmeiza and Aga, respectively. The highest infestation percentage (10.02 %) was found at Aga 2001, whereas the lowest (6.72 %) was found at Gemmeiza in the same growing season. Mono¬culture cotton plants harboured reliable' infestation percentages than that planted frontier maize; it was (7.08 and 7.03 %) in mono-culture cotton at Gemmeiza during both seasons, while it was (7.18 & 9.72 %) at Aga, respec¬tively. The infestation percentage on cotton that was planted frontier maize (under poly-culture techniques) was (4.65 & 4.31 %) at Gemmeiza during both seasons, while, it was (5.03 and 7.22 %) at Aga, respectively. The in¬festation percentages on maize was (10.7 & 8.85 %) at Gemmeiza in both 2000-2001 and (10.5 & 13.12 %) at Aga in the both growing seasons. As a result, poly-culture techniques maize and cotton reduced the infestation on cotton with boIl worms by 34.32 & 38.69 % at Gemmeiza with an average of 36%. For Aga it was 29.94 & 25.72 % with an average of 26%.

Summary in Arabic.

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