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초생재배와 합성피레스로이드계 조합처리가 귤응애의 발생양상에 미치는 단기효과

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Abstract
Citrus red mite, Panonychus citri Mcgregor (Acarina: Tetranychidae), is an important mite pest on citrus and the population patterns are known being largely variable according to practical conditions as found in other Tetranychid mites. However, the causing factors for the occurrence patterns are rarely tested quantitatively or qualitatively. In this study, consequently, split-plot degsin of grass planting (W: manual weeding, NW: chemical weeding, herbicide sprays) and pyrethroid spray (P: pyrethroid spray, NP: no pyrethroid spray) were treated to investigate the pattern of P. citri population among different cultural practices.
1. Two essential hypothesis were made to test the population dynamics: 1) weed planting promotes natural enemies via offering habitat and alternative food sources, resulting in the reduction of P. citri populations, and 2) Pyrethroid spray removes natural enemies via its non-selective toxicity, resulting in the increasement of P. citri populations. Habitat and pesticide effects were arbitrarily arranged from 0.1 to 1.0 by 0.1 intervals according to the relative impact, and the population sizes of phytophagous mite and natural enemy were estimated under the assumption of linearity and equality of the two variables. For the purpose of quantification of the hypothesis, the relative effects of factors were assigned as NW = 0.2, W = 0.8, NP = 0.2, and P = 0.8. Consequently, resultant expected population sizes were NW+P > NW+NP = W+P > W+NP for mite population and NW+P < NW+NP = W+P < W+NP for natural enemy population.
2. The populations of P. citri were converted to cumulative mite days (CMD) for the purpose of comparison. Based on autumn population, CMD was highest in NW+NP plot with the order of W+NP, NW+P and W+P plot in 2011. CMDs were lower in pyrethriod treatment plots than in non-pyrethriod treatment plots, being different from expectation in hypothesis. In non-pyrethriod plots, also, CMD was lower in W plot than in NW plot. The results in 2012 showed a similar trend with those in 2011.
3. The observed natural enemy populations (mainly Phytoseiids and Agistemus sp.) were not different largely from the expected values in the hypothesis. Although some discrepancy was occurred in NW+NP and W+NP plots in 2011, the observed values were almost same with expected values in 2012. In overall, pesticide effect was strongly significant and pyrthroids removed largely natural enemies. Although habitat (weeds) effect showed a conflict result, natural enemy population increased in W plots, when considering the increased autumn population relatively compared with that of spring population.
4. The hypothesis that pyrethroid sprays cause the outbreak of spider mite populations has been a widely-accepted theory. So, the decreased P. citri populations in pyrethroid (cypermethrin or deltamethrin) plots would be explained under the assumption of a strong repellent behavior of P. citri to the pyrethroids. A severe migration of P. citri populations may occurred in P plots with the establishment of natural enemies to some extent, resulting in being very lower P. citri population. Meanwhile, P. citri population may increase more in NP plots, because of limited P. citri migration out of NP plots and a possible influx of P citri into NP plots from adjacent P plots. Being delayed natural enemy population under the conditions above, P. citri population might exceed temporarily a economic injury level.
Author(s)
현승용
Issued Date
2013
Awarded Date
2013. 2
Type
Dissertation
URI
http://dcoll.jejunu.ac.kr/jsp/common/DcLoOrgPer.jsp?sItemId=000000006210
Affiliation
제주대학교 대학원
Department
대학원 농화학과
Advisor
김동순
Table Of Contents
I. 서 론 3
II. 연 구 사 5

III. 재료 및 방법 11
1. 실험 감귤원 및 시험구 배치 11
2. 2011년 실험 11
3. 2012년 실험 12
4. 분석방법 12
4-1. 가설의 설정 12
4-2. 누적응애발생일수(CMD) 계산 13
4-3. 통계분석 13

IV. 결 과 17
1. 2011년 귤응애 및 천적류 발생양상 17
1-1. 2011년 처리별 귤응애 발생양상 17
1-2. 2011년 처리별 천적류 발생양상 17
2. 2012년 귤응애 및 천적류 발생양상 24
2-1. 2012년 처리별 귤응애 발생양상 24
2-2. 2012년 처리별 천적류 발생양상 24

V. 고 찰 32
VI. 적 요 38
VII. 인 용 문 헌 40
Degree
Master
Publisher
제주대학교
Citation
현승용. (2013). 초생재배와 합성피레스로이드계 조합처리가 귤응애의 발생양상에 미치는 단기효과
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Graduate School of Industry > Environmental Biotechnology
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