Citation
Loke W.H., . and Heng C.K., . and Norlaili Basirun, . and Azman Rejab, . (1990) Non-target effects of neem Azadirachta indica A. Juss on Apanteles plutellae Kurdj. cabbage Sawi and Padi. [Proceedings Paper]
Abstract
Apanteles plutellae Kurdj. is an important endo-larval parasitoid exerting significant biological control effects on Plutella xylostella L. When A. plutellae cocoons were topically treated with neem oil/acetone solutions of 1.25 2.5 5.0 and 10.0 percent concentrations it was observed that adult eclosion of the parasitoids was significantly inhibited by neem oil concentrations of 2.5 percent or more. At 10.0 percent concentration no adult eclosion was observed. Treated parasitoid cocoons yielded adults which had reduced longevities as compared to those treated with acetone control. However no morphological deformities were observed. Spraying of neem oil of 5 concentrations viz. 0.5 1 2 3.0 and 4.0 percent onto cabbage sawi Chinese mustard and padi rice seedlings showed that there were phytotoxicity effects. The effects were particularly severe on cabbage in which concentrations of 3.0 percent and above killed all the treated plants after 3 rounds of weekly sprays. Treated plants that survived 4 rounds of spraying at the concentrations tested showed pronounced symptoms of scorching and growth retardation. No cabbage yield was obtained as an epidemic of softrot wiped out all the plants. In the case of sawi plants sprayed for 4 consecutive rounds with 3.0 and 4.0 percent neem oil had mortalities of 30.0 and 40.0 percent respectively. Surviving plants were affected showing scorching and growth retardation. Yields obtained showed that there was no significant difference between control and 0.5 percent neem oil. Yield were significantly depressed in the 3.0 and 4.0 percent treatments. Padi plants appeared to be more hardy. Scorching symptoms were only clearly observable on plants treated with neem oil of 2.0 percent or higher concentration. All treated plants survived and yielded rice grains. Although yields did not differ significantly plants treated with 2.0 percent or higher concentrations of neem oil exhibited non-uniform grain-ripening.
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Abstract
Apanteles plutellae Kurdj. is an important endo-larval parasitoid exerting significant biological control effects on Plutella xylostella L. When A. plutellae cocoons were topically treated with neem oil/acetone solutions of 1.25 2.5 5.0 and 10.0 percent concentrations it was observed that adult eclosion of the parasitoids was significantly inhibited by neem oil concentrations of 2.5 percent or more. At 10.0 percent concentration no adult eclosion was observed. Treated parasitoid cocoons yielded adults which had reduced longevities as compared to those treated with acetone control. However no morphological deformities were observed. Spraying of neem oil of 5 concentrations viz. 0.5 1 2 3.0 and 4.0 percent onto cabbage sawi Chinese mustard and padi rice seedlings showed that there were phytotoxicity effects. The effects were particularly severe on cabbage in which concentrations of 3.0 percent and above killed all the treated plants after 3 rounds of weekly sprays. Treated plants that survived 4 rounds of spraying at the concentrations tested showed pronounced symptoms of scorching and growth retardation. No cabbage yield was obtained as an epidemic of softrot wiped out all the plants. In the case of sawi plants sprayed for 4 consecutive rounds with 3.0 and 4.0 percent neem oil had mortalities of 30.0 and 40.0 percent respectively. Surviving plants were affected showing scorching and growth retardation. Yields obtained showed that there was no significant difference between control and 0.5 percent neem oil. Yield were significantly depressed in the 3.0 and 4.0 percent treatments. Padi plants appeared to be more hardy. Scorching symptoms were only clearly observable on plants treated with neem oil of 2.0 percent or higher concentration. All treated plants survived and yielded rice grains. Although yields did not differ significantly plants treated with 2.0 percent or higher concentrations of neem oil exhibited non-uniform grain-ripening.
Additional Metadata
| Item Type: | Proceedings Paper |
|---|---|
| Additional Information: | 4 tables 5 ref.; Summary En |
| AGROVOC Term: | AZADIRACHTA INDICA |
| AGROVOC Term: | APANTELES |
| AGROVOC Term: | PLUTELLA XYLOSTELLA |
| AGROVOC Term: | INSECTICIDAS DE ORIGEN VEGETAL |
| AGROVOC Term: | PLAGUICIDAS DE ORIGEN VEGETAL |
| AGROVOC Term: | REPOLLO |
| AGROVOC Term: | ORYZA |
| Geographical Term: | MALAYSIA |
| Depositing User: | Ms. Norfaezah Khomsan |
| Last Modified: | 24 Apr 2025 05:26 |
| URI: | http://webagris.upm.edu.my/id/eprint/14952 |
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