Research Of Major Weed Spread Structure And Sampling Technology Of Oil Sunflower In Summer Sowing In Western Area Of Henan

since 2003, the resercher studied wholely such as aiming at the occurrence characteristic of weed in summer seeding paints herbaceous plant field in west of Henan,competition relation between weed and crop,weed space distribution,output loss,the threshold value of economic defency and chemicals sieving specifically for different grass and working out technology directive rules for defending synthetically of summer seeding paints herbaceous plant Studying the research lasting for 3 years originally.the result as following:1 the weed in summer seeding paints herbaceous plant field.in west of Henan belongs to 32 section 112species,. Grave weed of damage has 23 kinds , belongs to 11 section. The purslane , horse Tang, oppose the branch amaranth , Indian mallow , green bristlegrass , Herbal Acalyphae , dry barnyard grass , cattle tendon grass occurrence quantity is more , the density is 35.60% , 22.73% , 13.27% , 9.06% , 8.64% , 4.33% , 7.04% , 2.22% respectively. By the admeasurement of aggregation degree indices to 6 kinds , ascertaining 6 kinds of weed such as horse Tang , barnyard grass grass , green bristlegrass , purslane , opposing the branch amaranth , Herbal Acalyphaewas aggregate in summer seeding paints herbaceous plant field ,this gathering distribution was caused by weed growth characteristic or environment when the weed density was very high;caused by some environment factor when the weed density was very low. Comparison by 5 kinds of way sampling, horse Tang uses "dyadic sampling at 5 points way best , barnyard grass grass and green bristlegrass use "Z type sampling at 15points way best , community uses the purslane , Herbal Acalyphae , oppose the branch amaranth without exception with "dyadic sampling of checkerboard" way best , entire weed Shan diagonal line sampling way best. this gathers distribution.2.Find out the competion relationship between weed and crop though inquiring into the weed occurencethe at different child-bearing period growth and the admeasurement of crop growth and bearing That the flower bud expects oil herbaceous plant seedling stage till now is the key period that weed endangers to oil herbaceous plant. Economy endangers oil herbaceous plant field weed allowing loss level be 8.08% ~ 10.39%. Economy of oil herbaceous plant field weed threshold value is 9 ~ 16 plant/ m2. Oil herbaceous plant and the weed's competition crisis are 14.02 ~ 16.47 ds phase.3.The systemly researchers were carried out about preventing and killing off by chemical method to summer seeding oil herbaceous plant field in west of Henan , a batch of chemicals were picked out which have fairly good weed-killing effect in different period. The stubble may select and use 20% gram of nothing trace before residual weed sowing seeds , thoroughness that 41% sweet grass phosphorus carries out on to unearthing weed already weeds out in the front, can select and use 20% gram of nothing trace and 33% Shi Tian adding supplemental the force-out drifting along with the weed being in progress to broadcasting front and not having unearthed weed face to face; The grass selling a dish at reduced prices but choosing exchanges , 48% fluorine laughs at a bier before sowing the queen seedling, weeding effect amounts to 80% the above and face to face oily herbaceous plant safety. The stem leaf is processing but gram of grass energy , 5% grass choosing 10.8% cover grass energy , 8.8% essence are phychic,4. according to the characteristic of oil herbaceous plant field weed occurrence and damage, work out technology directive rules- "defending against with the chemistry except that agriculture measure is subsidiary for giving first place to"for summer seeding paints herbaceous plant field weed in west of Henan .