The Creation And Construction Of Application Technology System Of Pendimethalin Control Weeds In Garlic Field

The weed species, community structure, weed change rule after herbicides application in garlic field were studied. Herbicides filtration and the combination whose principal part was pendimethalin were also studied, the results are as follows:1. Species harm characteristics and community structure in garlic field.The species and community structure of the weeds were investigated using 5 categories rating system by visual range estimation in garlic fields in Shandong, Henan, Hebei, Jiangsu and Shanxi province, which were the main garlic productive areas in China. The result indicated that weeds in these garlic fields almost belonged to 84 species, 20 families and the main growth pattern of the weeds was the mixture of grasses and broad weeds. The main grasses are: Equal Alopecurus, Wild Oat, Goat Grass, Japanese Bromegrass, Common Crabgrass, Goosegrass, Barnyardgrass, Indian lovergarass etc.; the main serious broad weeds are: Shepherdspurse, Flixweed Tansymustard, Conical Silene, Geminate Speedwell, Corn Gromell, Creepingthymeleaf Sandwort, Common Chickweed, Aquatic Malachium, Cow Soapwort, Wormseed Mustard, Peppergrass, Sunn Euphorbia, Pedunchlate Trigonotis, Tender Catchweed Bedstraw, Resroot Amaranth, Redroot amaranth, Wrinkledfruit amaranth, Lambsquaters, Purslane, Copperleaf and little thistle etc. Rice galingale was the main cyperaceae weed. The main weeds which happen at prophase are those which can live through winter, such as Equal Alopecurus, Wild Oat, Goat Grass, Japanese Bromegrass, Shepherdspurse, Flixweed Tansymustard,Conical Silene, Geminate Speedwell, Corn Gtomwell, Creepingthymeleaf Sandwort, Common Chickweed, Aquatic Malachium, Cow Soapwort, Wormseed Mustard, Peppergrass, Sunn Euphorbia, Pedunchlate Trigonotis, Tender Catchweed Bedstraw.The rules of the weeds happened are as follows: annual weeds, Perennial weeds and annual weeds happen alternately, and 4 fastigiums occur before winter or in spring. The number of the weeds which happen in tectorial garlic fields are more than that in hypaethral garlic fields, and the period in which the weeds harm in tectorial garlic fields are longer than that in hypaethral garlic fields.The weeds which happen in different area are different slightly, except that Shepherdspurse and Flixweed Tansymustard Tansymustard happen in all parts, Equal Alopecurus, Aquatic Malachium and Common Chickweed happen seriously in garlic and rice rotate fields, and Wild Oat and Lvy Glorybind happen seriously in garlic and corn rotate fields. Common Crabgrass, Goosegrass, Redroot Amaranth, and Lambsquaters happen seriously in all parts in autumn and in spring next year, in some areas Rice galingale happen seriously.The weeds in garlic fields are numerous, happen frequently and damage seriously. The occurring frequency of Shepherdspurse, Common Crabgrass, Flixweed Tansymustard were more than 80%, and the occurring frequency of Redroot Amaranth, Aquatic Malachium, Purslane, Lambsquaters were more than 60%.According to the 5 categories rating system, the areas occupied 71.8%, 69.6%, 68.2%, 59.9% and 54.3% respectively in which Shepherdspurse, Flixweed Tansymustard, Redroot Amaranth, Aquatic Malachium and Common Crabgrass damaged more than category 2 respectively; the areas occupied 52.1%, 51.1%, 44.5%, 44.3% and 39.5% respectively in which Aquatic Malachium, Flixweed Tansymustard,Redroot Amaranth, Lambsquaters and Shepherdspurse damaged more than category 3 respectively.There are many weed communities In garlic fields because of the long growth period , the numerous coming up fastigium and the fly-season damage of the main weed communities. Shepherdspurse, Flixweed Tansymustard and Common Crabgrass were the dominant species in the majority of weed communities. There are 2 main weed communities, one is Shepherdspurse and Aquatic Malachium mixed with Flixweed Tansymustard and Common Crabgrass, the other is Shepherdspurse and Flixweed Tansymustard mixed with Equal Alopecurus and Redroot Amaranth. 2. Influence of herbicides on weed community.The herbicides, pendimet...