|Title:||鳳梨粉介殼虫（Dysmicoccus brevipes Ckll.）之生態與鳳梨萎凋病關係之研究(II)||Other Titles:||Ecological Studies on Pineapple Mealybug (Dysmicoccus brevipes (Ckll.)) In Relation to Pineapple Wilt||Authors:||李錫山
|Keywords:||鳳梨粉介殼蟲||Issue Date:||1966||Publisher:||植病保護學會||Journal Volume:||8||Journal Issue:||3||Start page/Pages:||211-219||Source:||植物保護學會會刊||Abstract:||
The results of the seedling-inoculation period of this experiment have been previously reported (8). In this paper, it deals with the results of the mid-growth inoculation period and the bud-differential period when the pineapple plants were about six and twelve months old respectively.
The first typical wilt symptoms appeared mostly from 46 to 65 days after the mealybugs were placed to the pineapples. In the three inoculation periods, the midgrowth inoculation period took about two weeks later for showing the first typical wilt symptom than that of the other two periods. From the apperance of the first typical wilt symptom to the peak of wilt, it took about two months in the seedling-inoculation period and bud-differential inoculation periods, while about one month long in the mid-growth inoculation period.
Five pineapple plants from each treatment were pulled out after the completion of inoculation feeding for population-density examination and feeding-site observation of the mealybugs. Results showed that most of the mealybugs were found between the eleventh and thirtieth leaves from the center of the plant, but there was also a tendency that the mealybugs tended to spread to the inner or outer leaves as the infestation period lasted a little longer. It was also evident that almost all of the mealybugs fed on the lower portion of the leaf. This phenomenon may be explained by the habit of the mealybugs that they like to fix their bodies side by side or wedge into the crack.
The wilted plants recovered by sending out symptomless central new leaves when they were kept free from mealybugs infestation for certain period time. Among the three inoculation periods, recovery appeared more rapid in the mid-growth inoculation period than that of the seedling-inoculation period. There was almost no evidence of recovery in the bud-differential inoculation period when the plants were in the stage of bud differentation.
|Appears in Collections:||植物保護系|
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