齐齐哈尔市水稻田杂草群落变化趋势的分析

为明确齐齐哈尔市水稻田杂草种类、群落组成及危害状况,为高效防治水稻田杂草提供依据。采用倒置“Ｗ”形9点取样方法,进行定点系统观测与田间普查,田间调查方法为定点计数法与随机目测法,田间调查主要为杂草类别、群落组成结构和危害级别程度。结果表明：异型莎草、芦苇、稻稗、针蔺等杂草在稻田杂草群落出现频率在20年间明显下降,野慈姑、雨久花、鸭舌草、泽泻、稻李氏禾、葡茎剪股颖在杂草种群中的出现频率明显上升,杂草的危害程度随着其出现频率的变化而变化,造成很大危害。水稻田杂草群落模式由“禾本科杂草+莎草科杂草+阔叶类杂草”演替为“阔叶类杂草+禾本科杂草+莎草科杂草”,其中难治的恶性杂草种类增加且危害严重。

Weed Community Change Trend in Paddy Field of Qiqihar City

The aim was to clarify the weed species, community composition and damage status in paddy field of Qiqihar City, and provide a basis for effective prevention and treatment of weeds in paddy field. Using inversion "W" shape 9 sampling method, field survey and fixed point observation were carried out. The field survey included fixed point counting method and random visual observation method for the weed species, community composition and the status of damage. The results showed that the occurrence frequencies of Cyperus difformis L., Phragmites communis Trin, Echinochloa crus-galli P. Beauv., Eleocharis intersita Zinserl. etc. were decreasing, while that of Sagittaria sagittifolia L., Monochoria korsakowii Regel & Maack, Monochoria vaginalis, Alisma orientale Juzep, Leersia heraudra Swartz, Agrostis palustris were increasing in the 20 years. The extent of the damage of weeds varied with the frequency of their occurrence, and caused serious harm. Weed community in paddy field changed from“gramineous weed cyperaceous weed broad leaf weed” to“broad leaf weed gramineous weed cyperaceous weed”, of which, the occurrence of malignant weed species increased and caused more serious harm to rice.