Weed Control Methods in Schisandra Planting Fields

1. The survey results of weed species in Schisandra fields show that the weeds causing serious damage in Schisandra fields include barnyardgrass, crabgrass, amaranth, lambsquarters, field horsetail, foxtail, and shortawn foxtail, among which crabgrass, Asiatic dayflower, and lambsquarters cause particularly severe damage.

2. Conventional weed control in Schisandra orchards Conventional weed control in Schisandra orchards can be carried out together with intertillage of the orchard, 4 to 5 times per year, with a intertillage depth of about 10 cm, so that the soil is loose and well aerated, and it also plays a role in drought resistance and water conservation. Weeding is an important means of avoiding nutrient loss and ensuring that plants have sufficient nutrition for healthy growth. During weeding, do not injure the roots, and especially do not injure the aboveground main vines; once damaged, they are very likely to cause root rot, resulting in plant death.

3. Chemical weed control in Schisandra orchards Traditional manual weeding is labor-intensive and time-consuming. Using herbicides can effectively improve production efficiency. On the premise of fully mastering the properties of the chemicals and the application techniques, chemical weed control can be adopted.

(1) Quizalofop-p-ethyl Quizalofop-p-ethyl is a highly selective new post-emergence stem and leaf treatment herbicide for dry fields, and can effectively control annual grass weeds such as barnyardgrass, wild oat, crabgrass, goosegrass, shortawn foxtail, foxtail, Chinese sprangletop, and Polypogon fugax. Schisandra is transplanted from the seedling bed to the main field from late April to early May. After transplanting and seedling recovery, quizalofop-p-ethyl can be applied at any time during the vigorous growth period of grass weeds, but it is best to apply it at the 3- to 5-leaf stage of the weeds. For each mu, 70 ml of 1.5% quizalofop-p-ethyl can be used with 30 to 40 kg of water, fully stirred evenly, and then sprayed on the stems and leaves of the weeds. When controlling perennial weeds, the dose can be divided into two applications, which can improve the weeding effect; the interval between the two applications is 20 to 30 days.

When applying the chemical, note:

① Use a low dose when the weed leaf age is young, growth is luxuriant, and moisture conditions are good; use a high dose under drought conditions. When soil moisture is relatively high, it is beneficial to the absorption and translocation of quizalofop-p-ethyl by weeds. It is not suitable to apply the chemical during long-term drought without rain and when the relative air humidity is below 65%.

② Generally apply the chemical in the morning and evening. There should be no rain within 2 hours after application. In case of long-term drought, if there is rain recently, wait until the soil moisture in the field improves after the rain before applying the chemical. ③ Quizalofop-p-ethyl is an aryloxyphenoxypropionate herbicide and should not be mixed with hormone-type, sulfonylurea-type, or diphenyl ether-type herbicides such as 2,4-D, MCPA, and dicamba, bentazone, and other herbicides.

(2) Paraquat The English common name is paraquat, also known as gramoxone and paraquat dichloride, and the formulation is a 20% aqueous solution. Its characteristic is that it is a fast non-selective herbicide with contact action and a certain systemic action. It can be rapidly absorbed by the green tissues of plants and cause them to wither and die, but has no effect on non-green tissues. In soil, it quickly combines with the soil and becomes inactivated, and has no effect on plant roots, perennial underground stems, or perennial roots. It is suitable for controlling weeds in orchards, mulberry orchards, rubber plantations, and forest belts, and can also be used to control weeds in non-cultivated land, field ridges, and roadsides. For Schisandra orchards and nurseries, directed spraying can be adopted to control weeds. When the weeds have emerged completely and are in the vigorous growth period, use 100 to 200 ml of 20% aqueous solution per mu, add 25 kg of water, and evenly spray the stems and leaves of the weeds. When the weeds grow to more than 30 cm, the dosage should be doubled.

When applying the chemical, note:

① Paraquat is a non-selective herbicide. When used during the growth period of Schisandra, it must not contaminate the crop, so as to avoid phytotoxicity.

② Protective measures should be taken when preparing and spraying the chemical: wear rubber gloves, a mask, and work clothes. If the liquid splashes into the eyes or onto the skin, rinse immediately.