不同栽植期對水稻田雜草相之影響

Effect of Planting Date on Population and Density of Weeds in the Paddy Field

蕭巧玲(Chiao-Ling Hsiao) ； 楊純明(Chwen-Ming Yang) ； 李裕娟(Yuh-Jyuan Lee)

《台灣農業研究》 60卷2期 (2011/06) Pp. 125-138

https://doi.org/10.6156/JTAR/2011.06002.05

摘要

全球暖化及氣候快速變遷現象已對農作生產與農業環境帶來全面性的衝擊，農田雜草族群種類與數量也發生明顯的變化。本研究於2009年在行政院農委會農業試驗所農場（臺中市霧峰區）兩期稻作期間，以春分／大暑為中心之溫度梯度進行10次水稻栽植期，探討溫度及光照對水稻田雜草相之影響。每個栽植期皆同時種植4個良質稻種，即桃園4號(TY 4)、臺稉9號(TK 9)、臺農71號(TNG 71)及高雄145號(KH 145)，且均於插秧後28天進行雜草取樣及調查族群種類與數量。又收集試區鄰近農試所一級農業氣象測站之氣象測值，計算累加日均溫(ADMAT)、累加日照時數(ADSH)及累加日射量(ADIR)等氣象變因數值，以分析稻田雜草相之氣象環境效應及暖化情境的影響。結果顯示試驗區內雜草科別數及種別數有隨著ADMAT增加而上升的趨勢，尤以TY 4及TK 9田區達顯著水準；ADSH對雜草種類之影響呈現不顯著的凹型二次曲線分佈，ADIR對雜草族群種類之影響趨勢近似於ADMAT，然僅TK 9田區顯著相關。若將4個良質稻種之栽培田區全部雜草資料合併分析，無論雜草科別數或種別數，皆與此三種氣象變因顯著相關，其中ADMAT及ADIR為曲線正相關，ADSH為凹型曲線相關。又比較4個良質稻種田區在兩期稻作期間所調查之雜草相，發現一期稻作之5個栽植期合計以滿天星數量最多，其次為紅骨草；二期稻作之5個栽植期合計則以尖瓣花及多花水莧之數量居前二位。此4種雜草在水稻秧苗移植後4週所調查之數量，經與ADMAT比較呈現出凸型或凹型曲線關係。若合併兩期稻作10個不同栽植期調查之全部田區雜草資料，總數以尖瓣花數量最多，且其單位面積植株密度隨著ADMAT的增加而升高，其次為滿天星、千金子及稗草。綜合試驗結果，顯示不同水稻品種栽植田區之雜草種類與數量在期作間互異，且受到栽植期氣溫之影響。

關鍵字

栽植期 ； 水稻 ； 雜草種類 ； 雜草密度

並列摘要

Global warming and climate change has become a major issue on crop production and agricultural environment, including changes in population, density and distribution of weeds. A field study was conducted in 2009 at the experimental farm of Taiwan Agricultural Research Institute, Wufeng, Taichung, Taiwan to determine effects of planting date, in terms of temperature and solar radiation, on weed population and density in the spring crop (first crop of 2009) and the fall crop (second crop of 2009) of paddy rice (Oriza sativa). Seedlings (3-4 leaf-stage) of four quality rice cultivars, TY 4, TK 9, TNG 71 and KH 145, were transplanted into the paddy field at five different dates in each crop season. Data on accumulated values of daily mean air temperature (ADMAT), daily sunshine hours (ADSH) and daily irradiance (ADIR) of different planting periods in each crop season were recorded. The populations and densities of weeds were collected at 4 weeks after transplanting. Results showed that number of family and species of weeds increased significantly (P＜0.05) with increasing value of ADMAT for the cultivars TY 4 and TK 9. Number of family and species of weeds increased significantly (P＜0.05) with increasing value of ADIR for the cultivar TK9 but no significant difference (P＞0.05) with increasing value of ADSH for all cultivars tested. Results of pooled data of four rice cultivars showed that changes in number of family and species of weeds were correlated with these three meteorological parameters in a curvilinear trend. In the plots of all four rice cultivars, the most predominant weed species (with the highest density) in the first crop season was Altemanthera sessilis, followed by Rotala indica, whereas the most predominant weed species in the second crop season was Sphenoclea zeylanica, followed by Ammannia multiflora. Populations of these four weed species were curvilinearly correlated to changes of ADMAT. Results of combined data of both crop seasons (with 10 planting periods in total) showed that the population density was the highest for Sphenoclea zeylanica, followed by Alternanthera sessilis, Leptochloa chinensis, and Echinochloa crus-galli and the increase of population density was associated with the increase of ADMAT values. This study suggests that weed species and density in the first and second crops of paddy rice are affected by rice cultivars and values of ADMAT in the planting period.

並列關鍵字

Planting period ； Rice paddy ； Weed population ； Weed density