الفهرس 
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Abstract
SUMMARY
Field experiments were carried out in early summer plantations (mid-April) and summer plantation mid-July sowing of maize plants throughout 2002 & 2003 seasons in the Experimental Farm of Faculty of Agriculture at Moshtohor (Qalubiyah Governorate) to study the efficacies of some plant extracts as lupin seeds & bestachia leaves’ extracts in water, methanol and acetone in addition to jojoba and neem oils formulations to maize plants in suppressing Sesamia cretica and Ostrinia nubilalis (Hubn.) infestations and the effects on the resultant yield. Parallel to the field studies, surviving of predators and studied
effects of plant extracts on them were studied, throughout 2003 season
for 0. nubilalis predators and 2004 season for S. cretica. Laboratory
studies were also conducted to find out the toxicity effect of the field
assayed plant extracts treatments on S. cretica and 0. nubilalis larvae
treated in the 15t, 3rd and 5’h
instars. Also some histological studies on mid-gut and integuments of S. cretica & 0. nubilalis larvae after treated by assayed plant extracts.
Results may be summarized as follows:
1. Effects of field applications for plant extract treatments on early summer maize plantations
1.1. On S. cretica egg-masses and number of eggs:
Applications of the assayed plant extracts treatments to maize plants caused, significant, reduction in S. cretica egg-mass counts after first application, 24 hours and 5 days than control (7.4 and 6.5 egg-masses / 30 plants), respectively. Means of two year results indicated that the severest effect occurred by bestachia extract in methanol, (1 egg-mass /
30 plants after 24 hours). While, the severest effect occurred by Nat 1 (0.9 egg-mass/ 30 plants after 5 days), followed by Bioneem (1 egg-masses / 30 plants). Also, application of the assayed plant extract treatments to maize plants caused, significant reductions in total numbers of S. cretica eggs after first application; 24 hours and 5 days than control (63.6 and 65.8 eggs / 30 plants, respectively). Mean of two years results indicated that the severest effect occurred by Bioneem (15 eggs / 30 plants) follow it bestachia extract in methanol and acetone (15.4 and 17.6 eggs / 30 plants, respectively). While, 5 days from first application, also caused significant reductions. Mean of two years results indicated that the severest effect occurred by Nat 1 (5.4 eggs / 30 plants) follow it Bioneem, bestachia extract in methanol and acetone (8.8, 12.9 and 13
eggs / 30 plants).
1.2. On infestation by S. cretica larvae:
All treatments caused significant reductions in the number of S. cretica larvae infesting maize plants than control. The highest efficacy occurred by using Nat I at different inspections, 5 days from l’” application, 24 hours & 5 days from ri application and 24 hours from 3rd application caused (55.3, 29.5, 31.5 and 15.4 larvae / 20 plants, as means of two years results indicating reductions 76.2, 81.4, 89.5 and 65.5% than
control, respectively).