Effects of Neem Extracts on the Feeding, Survival, Longevity and Fecundity of African Bollworm, Helicoverpa Armigera (Hubner) (Lepidoptera: Noctuidae) on Cotton
| dc.contributor.advisor | Getu, Emana (PhD) | |
| dc.contributor.advisor | Terefe, Geremew (PhD) | |
| dc.contributor.author | Wondafrash, Mesfin | |
| dc.date.accessioned | 2018-07-05T13:13:27Z | |
| dc.date.accessioned | 2023-11-08T16:32:48Z | |
| dc.date.available | 2018-07-05T13:13:27Z | |
| dc.date.available | 2023-11-08T16:32:48Z | |
| dc.date.issued | 2007-07 | |
| dc.description.abstract | The effects of neem oil (Nimbecidine 0.03% Aza) and water extracts of neem seed and leaf were studied each at three different concentration levels on various developmental stages of African bollworm both under laboratory and field conditions at Werer Agricultural Research Center. The laboratory study comprised of square dip and larval immersion experiments, both replicated three times using Completely Randomized Design. Whereas the field experiment was conducted using a Randomized Complete Block Design in three replications to verify neem extracts as a botanical insecticide under field condition. Mean mortality of Helicoverpa armigera larvae ranged from 4.67- 8.00 in square dip experiment and 3.67-6.00 in larval immersion experiment. While control mortality was 0.33 & 1.00 in square dip and larval immersion experiment, respectively. Lower number of damaged squares, ranging from 1.00-4.67 were observed in square dip experiment from different concentration levels of Nimbecidine and water extracts of neem seed and leaf. Significantly lower mean weight of artificial diet consumption (0.18-0.68 & 0.43-0.78g) was recorded at 6 & 9 DAT, respectively from various concentration levels of Nimbecidine and water extracts of neem seed and leaf in larval immersion experiment. Moreover, higher percent weight loss of ABW larvae, lower pupal weight, relatively extended duration at the larval stage, higher number of larvalpupal intermediates, lower number of eggs of which the majority are non-fertile as compared to the control were recorded from the various concentration levels of water extracts of neem seed and leaf and Nimbecidine in square dip and larval immersion experiment. However, results of field experiment have indicated that Nimbecidine and water extracts of neem seed and leaf have non-significant effect on the survival of ABW larvae, damaged flowers, squares and bolls in all rounds of spray application and in combined analysis. Moreover, no yield advantage was obtained from neem extracts. | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/123456789/6744 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Biology | en_US |
| dc.title | Effects of Neem Extracts on the Feeding, Survival, Longevity and Fecundity of African Bollworm, Helicoverpa Armigera (Hubner) (Lepidoptera: Noctuidae) on Cotton | en_US |
| dc.type | Thesis | en_US |