Rice seedling herbicide damage prevention and control measures

Quinacrine phytotoxicity can occur in rice fields under certain conditions. There are three main scenarios where this issue may arise. First, pre-application during the two-leaf and one-heart stage: 15 days after treatment, the seedlings' leaves darken, and the heart leaves begin to curl longitudinally from the leaf sheath, forming an onion-like tube. The new leaves must break through this structure to emerge, but once they do, they often fail to grow properly. Usually, it takes 2-3 more leaves for the seedlings to recover. In severe cases, the new leaves cannot appear at all, leading to plant death.

Second, over-application is a common cause of injury. The recommended dosage for 36% dichlorobenzyl WP is 60 grams per mu. However, in some fields with older weeds, farmers might increase the dose to 90–120 grams per mu, which can lead to phytotoxic effects on young rice plants. Symptoms typically appear within 10–15 days after application and last around 15–20 days. The onion tubes form, and the leaf color becomes slightly lighter than before. New leaves struggle to break through the tubes, causing growth issues.

Third, improper spraying methods, such as using a mist sprayer with high concentration, can also cause damage. To ensure proper dilution, chloroquine acid is usually applied manually with 30 kg of water per mu. If a mist sprayer is used instead, only 10–15 kg of water is added, resulting in a higher concentration. Within 10 days, the seedlings become stunted, their leaves darken, and onion-like leaves appear in the field. Without timely intervention, recovery may be slow or not possible.

To prevent quinacrine injury, two key points should be followed. First, use the right timing and dosage. It is generally safe to apply quinacrine during the two-leaf and one-heart stage. However, in direct-seeded rice fields with uneven weed ages, it's better to delay application until the three-leaf stage. At this point, the weeds are more mature, so the dosage should be increased accordingly. For 36% dichlorobenzyl WP, 80–90 grams per mu is recommended, and should not exceed 100 grams.

Second, proper application techniques are essential. Before applying the herbicide, ensure the field has enough water so that the entire plant receives the treatment. Avoid watering for 24 hours after application to allow full absorption by the weeds. Also, avoid re-spraying the same area to prevent overdosing.

If the rice has already been damaged by quinacrine, immediate action should be taken to promote recovery. Applying compound zinc fertilizers in the field can help. Foliar sprays and plant growth regulators like Ai Zengmei (Propanolactone) or Nai'an can also be used. After 10–15 days of treatment, although the old leaves may not fully open, new leaves should grow normally, indicating a positive recovery trend.

ELISA Analyzer

Processing high-throughput samples, intelligent reuse for large-capacity publishing, work surface: 200cm, 8 sample injection needles, 12 temperature-controlled incubation positions, 12 room temperature incubation positions, 32 plate storage positions, Sunrise microplate reader, HydroFlex plate washer, up to 512 specimens, sequential loading of samples, reagents, microplates Parallel loading of up to 6 plates for fast dispensing.

The automatic enzyme immunoassay analyzer is based on the principle that the enzyme and the substrate can produce a color reaction, the absorption lines of different substances have different characteristics, and strictly abide by the Lambert-Beer law, quantitative and qualitative analysis of substances. instrument. The method of analyzing the content of various enzymes such as antigen or antibody generally mainly adopts colorimetric method. In practice, spectrophotometry is the basic working principle of an automatic enzyme immunoassay analyzer. The light emitted by the light source lamp becomes a beam of monochromatic light after passing through a filter or a monochromator. The monochromatic light beam passes through the sample to be tested in the microtiter plate, and part of the monochromatic light beam is absorbed by the sample and reaches the photodetector. The intensity of the light signal projected on it is converted into the magnitude of the electrical signal by the photodetector. This electrical signal is processed by pre-amplification, logarithmic amplification, analog-to-digital conversion, etc., and then sent to the microprocessor for data processing and calculation, and the test results are output by the display and printer. The microprocessor completes the movement in the X and Y directions of the mechanical drive through the control circuit.
The automatic enzyme immunoassay analyzer adds the sample to the microwells of the pre-coated antigen or antibody microtiter plate, washes after the reaction, removes the unseparated ligand, then adds the enzyme isolate, after incubation, washes again , remove the unseparated compound, and then add the enzyme substrate, after the reaction, the colored final product is formed, and the stop solution is added to stop the reaction. The absorbance of each microwell of the microtiter plate is read by the wavelength that has been set by the spectrophotometer. The concentration value of the analyte in the sample is calculated by the absorbance value of the sample and the standard curve, so that the quantitative result can be obtained, or the absorbance of the sample is compared with that of the standard product, so that the positive or negative qualitative result can be obtained.

ELISA analyzer,enzyme immunoassay workstation,automatic enzyme immunoassay analyzer,automatic enzyme immunoassay system

Jilin Sinoscience Technology Co. LTD , https://www.jlgkscience.com