CHEMOTHERAPEUTIC AND BIOCHEMICAL ACTIVITIES OF SOME FUNGICIDES AGAINST SQUASH DOWNY MILDEW DISEASE | ||||
| Journal of Plant Protection and Pathology | ||||
| Article 3, Volume 27, Issue 10, October 2002, Page 7017-7024 PDF (2.64 MB) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/jppp.2002.255154 | ||||
 View on SCiNiTO | ||||
| Authors | ||||
| M. G.M EI-Sherief1; EI-S.A.M Abdallah2 | ||||
| 1Agricultural Research Center, Central Agricultural Pesticides Laboratory, Integrated Control Laboratory, Sabahia, Alexandria, Egypt. | ||||
| 2Department of Pesticide Chemistry, Faculty of Agriculture, Alexandria University, Alexandria, Egypt 21545. | ||||
| Abstract | ||||
| The potency of five selected fungicides as chemotherapeutic agents against squash downy mildew was studied as well as their effect on biochemical changes of the host plant as chlorophyll, p-carotene and sugar contents, in addition to polyphenol oxidase activity. The fungicides testecd were propamocarb hydrochloride (Previcur-N), mikal, mancozeb (Diathane M-45), Ridomil-Plus (metalaxyl-plus) and tolclofos-methyl (Rizolex). The results revealed that: 1) Propamocarb hydrochloride and mikal (systemic fungicides) were highly effective in reducing Pseudoperonospora cubensis infection indicated by low disease index and high recovery of infected squash leaves. In contrast, non-systematic fungicides as tolclofos-methyl and mancozeb were lowest affective in this respect. 2) P .. cubensis infection caused significant decrease in chlorophyll content, p-carotene content and polyphenol oxidase activity of squash leaves. Sugar content was insensitive toward downy mildew causal pathogen infection. 3) Fungicide treatments alone showed a feeble effect against chlorophyll content, p-carotene contents and polyphenol oxidase activity of squash leaves, while sugar content was increased Significantly especially due to mikal treatments. 4) Combinations of downy mildew infection and fungicide treatments was in favor of producing healthy plants and increasing some biochemical components related to the resistance phenomenon as sugar content and polypenol oxidase activity of squash leaves. The pigment contents represented as chlorophyll and p-carotene contents, were increased slightly due to therapeutic effect of fungicides, however, the increasing value was not able to restore the values of non-infected plants especially with p- carotene content. | ||||
|
Statistics Article View: 40 PDF Download: 161 |
||||
