Studies On Weed Species, Characteristics And Ecological Habits In Apple Orchard In Baoding

Grass disaster has become one of major factors that influence fruit tree growth,quality and yield of fruits, and it restricts the development of fruit economic indus-try. Recent studies from home and abroad on orchard weeds focus on the varietiesand control methods in different regions. However, studies on the selection and re-maining of benign grass varieties are only a small minority and researches of theinvestigation into weeds developing in different regions of Hebei province remaininsufficient. The object is to remove the apple orchard weeds in scientific ways,and to provide reasonable suggestions about selecting grass varieties in natural sodculture. In this experiment, samples were collected by adopting an inverted W pat-tern with9sampling points. Apple orchard weeds, as well as measure grass yield,root system and nutrient substance of dominant weed in this region were investi-gated in Baoding,Hebei province systematically. Meanwhile, the numerical taxonomyand Sequence analysis of summer weed population were adopted by Two-Way Indi-cator Species Analysis(TWINSPAN) and Detrended Correspondence Analysis（DCA）.The results are as follows.1. A total of67kinds of weed species appeared in the apple orchard in Baoding, andthey belonged to26families,58genera. Asteraceae were a total of17species which wasmore than others, and followed by Poaceae species, a total of8species. Among these therewere40kinds of weeds in spring,56kinds of weeds in summer and48kinds of weeds infall.2. In apple orchards of Baoding, there are12kinds of main weed species in spring,which are Capsella bursapastoris, Chenopodium serotinum, Chenopodium album,Chenopodium glaucum, Trigonotis peduncularis, Lagopsis supine, Viola philippica,Lactuca elata, Calystegia hederacea, Amaranthus tricolor, Cirsium segetum, Setariaviridis，10kinds in the summer, which are Mazus japonicus, Setaria viridis, Amaranthustricolor, Chenopodium serotinum, Portulaca oleracea, Eleusine indica, Capsellabursapastoris, Lagopsis supine, Cirsium segetum, Digitaria sanguinalis, and8kinds in theautumn, which are Cirsium segetum, Trigonotis peduncularis, Hypecoum erectum,Portulaca oleracea, Eleusine indica, Convolvulus arvensis, Malva verticillata, Bothriospermum chinense.In terms of worst weed species, there are15kinds in spring, which are Ixerissonchifolia, Descurainia Sophia, Rehmannia glutinosa, Ipomoea nil, Humulus scandens,Calystegia hederacea, Artemisia annua, Hypecoum erectum, Trigonotis peduncularis,Lagopsis supine, Hemisteptia lyrata, Convolvulus arvensis, Amaranthus tricolor,Chenopodium serotinum, Artemisia capillaries,13kinds in summer, which areAmaranthus tricolor, Hypecoum erectum, Artemisia capillaries, Lagopsis supine,Chenopodium glaucum, Chenopodium serotinum, Calystegia hederacea, Chenopodiumalbum, Convolvulus arvensis, Rehmannia glutinosa, Ipomoea nil, Humulus scandens, Viciasepium, and11kinds in the autumn, and they are Cirsium segetum, Rehmannia glutinosa,Bidens pilosa, Hypecoum erectum, Solanum nigrum, Hemisteptia lyrata, Artemisiacapillaries, Convolvulus arvensis, Calystegia hederacea, Ipomoea nil, Vicia sepium.3. In apple orchards of Baoding, the taproot lengths of dominant weed species arebetween8cm and23cm, the diameter of taproot are between0.4mm and10.2mm, and thesurface area of root system are between2.2cm2and64.8cm2. The roots of dominant weedspecies are shallow, and the most of roots are not huge or stout.4. Among the dominant weed species in the apple orchard in Baoding, the highescontent of K, Mg, P of the weed is Portulaca oleracea, the highest content of N、Fe、Mnof weeds respectively is Malva verticillata, Lagopsis supine, Eleusine indica, the highestcontent of Cu、Ca of the weed is Capsella bursapastoris, the highest content levels of B、Zn of the weed is Chenopodium serotinum.5. TWINSPAN were conducted to classify the summer weeds, which divided the63quadrats into7groups of summer weeds communities. The classification results betterreflected the relationships between weeds communities and environment, that soil moistureand soil nutrient. It was tested by DCA dimensional ordination.The soil moisture gradually decreased from left to right along the axis of DCA, andquadrats transitted from wetland plants to mesophytes, and further transitted to themesoxerophytes. From the bottom to the top, the soil nutrient gradually reduced. Dominantspecies of the quadrats from soil demanding species gradually transitted to the adaptableweeds that not strictly required.6. Grass species applied to natural grass method that is used to build gardens in appleorchard of Baoding are Digitaria sanguinalis, Portulaca oleracea, Setaria viridis,Eleusine indica.