Naphthaleneacetic acid (sodium) is a plant growth regulator belonging to the auxin class. In addition to the basic functions of general auxins, it can also promote the formation of adventitious roots and roots in plants, and is used to promote seed rooting, cutting rooting, and fibrous root growth in solanaceous crops. It can promote the rapid expansion of fruits and tubers, so it can be used as a growth promoter in vegetables and fruit trees. It can improve flowering and fruit setting rates, prevent flower and fruit drop, and has an anti-drop function. It can not only increase yield and improve quality, promote lush foliage and robust plants, but also effectively improve the crop's resistance to drought, cold, waterlogging, disease, salinity, and stress.

Application dosage

(1) Promoting the Formation of Adventitious Roots and Roots

Before grape cuttings, soaking the branches in a 100~200 mg/L solution can promote rooting, rapid sprouting, and robust plant development.

Tree transplanting: Dipping the roots in a 100-200 mg/L solution before transplanting promotes root growth and increases survival rate.

For tea, mulberry, oak, and dawn redwood, soaking the base of cuttings in a 10-15 mg/L solution for 24 hours promotes root growth.

(2) Promoting rapid fruit and tuber enlargement:

For sweet potatoes, bundle the vines together, dip the base in a 1-inch-deep solution of 10-20 mg/L, and transplant after 6 hours; or dip the vines in an 80-100 mg/L solution for 3 seconds and transplant immediately; this improves survival rate, enlarges tubers, and increases yield.

For radishes and cabbages, soaking seeds in a 15-30 mg/L solution for 12 hours, rinsing 1-2 times with clean water, and sowing after drying promotes fruit enlargement and increases yield. 

(3) Improve fruit set rate, protect flowers and fruits, and prevent fruit drop.

Citrus: Spray the fruit stem with a 40-60 mg/L solution 15 days before harvest to prevent pre-harvest fruit drop and increase yield.

Apple, Pear, and Jujube: Spray the entire plant with a 15-20 mg/L solution during the young fruit stage, starting 45 days before harvest, spraying every 15 days for 2-3 times to promote growth, prevent pre-harvest fruit drop, and increase yield.

Watermelon: Dip or spray the flowers with a 20-30 mg/L solution when the female flowers first open to improve fruit set rate.

Cotton: Spray the leaves with a 1-8 mg/L solution starting during the peak flowering period, spraying every 10-15 days for a total of three times to prevent bud and boll drop.

Chili Pepper: Spray the entire plant with a 20 mg/L solution during the flowering period to prevent flower drop and promote pepper formation.

(4) Promotes growth, strengthens plants, increases yield, and improves quality.

For wheat: Soak seeds in a 10-20 mg/L solution for 6-12 hours, rinse 1-2 times with clean water, dry, and then sow. Before jointing, spray with a 15-25 mg/L solution. During tillering, spray the flag leaf and panicle with a 20-30 mg/L solution to promote tillering and increase the panicle formation rate. After application, it can improve salt and alkali resistance, increase yield, increase thousand-grain weight, increase the number of grains per panicle, and improve resistance to hot and dry winds, thus increasing yield.

For rice: Soak seeds in a 10-20 mg/L solution for 6 hours before transplanting. Spray the flag leaf and panicle with a 20-30 mg/L solution to promote greening, make plants robust, and increase yield.

For rice seedbeds: Use a concentration of 3-10 mg/L for foliar spraying to regulate rice growth.

For corn and millet, soak seeds in a 20-30 mg/L solution for 12 hours, rinse 1-2 times with clean water, and sow after drying. Foliar spraying with a 15-20 mg/L solution during the growing season can promote growth and increase yield.

For cotton, foliar spraying with a 1-8 mg/L solution can regulate growth.

For tomatoes and eggplants, foliar spraying with a 5-12 mg/L solution before transplanting and starting at flowering, once every 10-15 days for a total of 3 times, can promote growth and increase yield.

For cucumbers, spraying the entire plant with a 5-20 mg/L solution 1-2 times during the growing season can increase female flower density and regulate growth.

For legumes, soak seeds in a 10-20 mg/L solution for 0.5-1 hour before sowing; spraying with a 5-20 mg/L solution 2-3 times during the growing season can promote growth, accelerate ripening, and increase yield.

Potatoes: Soaking tubers in a 10-20 mg/L solution for 12-24 hours can promote growth.

Pineapples: Spraying leaf buds and flower buds with a 10 mg/L solution before flowering; spraying young fruits with a 20 mg/L solution 2-3 times during fruit formation; injecting 30 mL of a 15-20 mg/L solution into the plant center during the later stages of vegetative growth can promote growth and increase yield.

Sugarcane: Foliar spraying with a 15-20 mg/L solution 2-3 times during the trimming stage can promote growth and increase yield.

Apples: Foliar spraying with a 30-50 mg/L concentration 1-2 times can significantly increase yield.

Lemons: Spraying the lemon canopy with a 0.1% solution can accelerate fruit ripening and increase yield.

Tobacco: Foliar spraying with a 10-20 mg/L solution 2-3 times during the growing season can regulate tobacco plant growth and improve leaf quality.

Precautions

(1) Naphthaleneacetic acid (NAA) is poorly soluble in cold water. When preparing the solution, first dissolve it in a small amount of alcohol, then dilute with water, or first mix with a small amount of water to form a paste, then add an appropriate amount of water, and finally add sodium bicarbonate (baking soda) and stir until completely dissolved.

(2) Using this solution on early-maturing apple varieties for flower and fruit thinning can easily cause phytotoxicity. Using 40 mg/L on Qiubai pears can cause yield reduction; excessively high concentrations can cause deformities, leaf drop, and leaf abscission. Using more than 50 mg/L on figs can cause phytotoxicity. Excessive use on watermelons and cantaloupes can easily cause phytotoxicity.

(3) It can cause poisoning through the esophagus, resulting in liver and kidney damage. There is no specific antidote. If poisoning symptoms appear, seek immediate medical attention.