In summer sisal weeding, glyphosate isopropylammonium salt works effectively only when applied in this way.

In sisal fields, annual weeds and perennial noxious weeds compete with the crop for water, nutrients, and light, and fields with severe weed infestation show significant yield reduction. Herbicide selection should be based on the target weed species—annual weeds or perennial noxious weeds—and the appropriate growth stage must be identified. Glyphosate-isopropylammonium 30% glyphosate-isopropylammonium aqueous solution (AS) is registered for the control of annual weeds and perennial noxious weeds in sisal fields.

For annual weeds in sisal fields, the herbicides used for grasses differ from those for broadleaf weeds, and the application methods also vary between pre-emergence and post-emergence treatments. For soil residual (pre-emergence) control, the herbicide should be applied after sowing but before crop emergence, forming a herbicide film over the soil surface. For post-emergence foliar treatment, spray directionally when weeds are at the 3–5 leaf stage and when the crop is relatively safe.

Glyphosate isopropylamine salt 30% glyphosate isopropylamine salt aqueous solution (AS), registration certificate No. PD85159-15 (subject to the actual label). Used for the control of annual weeds and perennial noxious weeds in sisal fields at a rate of 250–500 mL per mu, applied by directed spraying. Dilute with water according to the weed spectrum and crop growth stage, and spray evenly, taking care to avoid spray drift onto the crop.

For stem and leaf herbicide application, lower the nozzle and spray only the weeds to prevent spray drift from reaching the crop and causing injury; do not spray on windy days or before rain. Dosage varies considerably among different formulations—conduct a small-scale trial first before large-scale application. Always follow the label instructions.