Use of paddy field herbicides

First, weeds can be divided into the following three categories:
Gramineous weeds: The main morphological features are long and narrow leaves, cylindrical stems, often hollow between nodes and nodes, roots are fibrous roots, such as valerian, crabgrass, and tendon grass.
Cyper weed: The main morphological feature is that the stem is triangular, solid, knotless, individual cylindrical, hollow. Such as fragrant aconite, broken rice sedge, leeches and so on.
Broadleaf weeds: The main morphological features are round, heart-shaped or rhomboid, with veins usually reticular and round or square. Such as hollow lotus seeds, a year canopy and so on.
Among them, weeds and sedge weeds are collectively referred to as monocotyledonous weeds. Broadleaf weeds are also called dicotyledon weeds. Gramineous weeds include: valerian, thousand gold, double-spotted gar, horse stalk, foxtail, goosegrass, valerian, wild oats, etc. The sedge weeds include: sedges, flat stalks, water sedges, sunshine sedges, cow felts, broken sedges, wild crickets, etc. Broad-leaved weeds include: kohlrabi, ragweed, glutinous vegetables, noodles, and a thin leaf.
Second, the principle of herbicide weeding in paddy fields:
The occurrence of weeds has at least two peaks: the first peak is the main peak, which occurs 5 days to 7 days after sowing, and generally accounts for about 60% of the total grass yield. The second peak is 7 days to 20 days after sowing, and generally accounts for about 25% of the total amount of grass.
1 The herbicides are all pre-emergence herbicides; for example, pretilachlor, butachlor, acetochlor, metolachlor, and benzilamide.
2 spray agents mostly use its selectivity principle; rice Jie (pentaflufenamide), gold (cyanofluoroacetate), quinclorac, bensulfuron, pyrazosulfuron.
Since rice seeds have been germinated with roots and can absorb safeners, they are not affected by herbicides. Weed seeds absorb herbicides when they germinate, but they have no roots and cannot absorb safeners, so they can be killed by herbicides. Safety agents are very important! It is also important that rice germination has roots.
Third, the choice of herbicides:
At present, herbicides in paddy fields are mostly pre-emergence herbicides, and 2-3 components are used to control single and dicotyledon weeds. Use weeds, weeds, and selectivity to control weeds.
1 position difference: such as transplanting and throwing cockroaches, for acetochlor, pretilachlor, butachlor and other amides, monocotyledonous plants act by bud tip growth point absorption agent, broad-leaved plants absorb by root tip growth point Medicament, so the use of rice and weed height is not the same, water retention floods monocotyledon weed heart leaves, play a grass killing effect; while rice heart leaves above the water surface, it is relatively safe. If there is heavy rain or too deep irrigation, it will also have herbicidal effect on rice; if the irrigation is too shallow, the water retention time is less than 3 days, or the field is uneven, the weeding effect will be poor.
2 Unearthed time: First, let the rice grow long by breeding or germination, and then use the difference to weed.
3 Selectivity: such as bensulfuron-methyl, quinclorac, cyhalofop-lam, penoxsulam and other agents are used to weed the plants by using them for the safety of weeds. Therefore, factors such as water use in different fields, soil conditions in the field, soil conditions, etc. have a great influence on the herbicide effect, and even phytotoxicity occurs.
Fourth, common transplanting, throwing field herbicides:
Amide (acetochlor) + sulfonylurea (bensulfuron-methyl): amides such as acetochlor mainly control grass weeds, bensulfuron-methyl mainly control broadleaf weeds (duckweed), sedge (Sancha grass, wild donkey), etc.;
For a penny, the price of the herbicide depends on the content and proportion of the active ingredient of the original drug, and the safety (adding a safener). For example, increasing the content of acetochlor and reducing the content of bensulfuron-methyl to reduce the cost, but leading to poor control of broadleaf grass.
Characteristics of amide herbicides:
1. Almost all varieties are special herbicides for controlling annual grass weeds. The control effect on broadleaf weeds is poor. The activity is as follows: acetochlor > metolachlor = propisochloramine > butachlor > Alachlor > oxachlor
2. Most of the varieties are soil treatment agents, which are mainly applied before the crops are budded. The main absorption site of monocotyledons is the young shoots (the coleoptile), while the dicotyledons are mainly absorbed by the young roots (hypocotyls), followed by the young shoots.
3. The mechanism of action of most varieties is to inhibit seed germination and shoot growth, so that the young shoots are seriously dwarfed and eventually die. Enemy is the inhibition of photosynthesis in plants.
4. The choice of the median difference in the soil treatment agent plays a larger role.
5. For soil treatment agents, the duration of effect is generally short. Generally 1-3 months, it is easy to degrade in the plant.
【Comment】 【Print this article】 【Close this page】 【Large, medium and small】

Industry Green House

Jilin Yidao Technology Co., Ltd , https://www.cniopticsqm.com