Naphthaleneacetic acid (NAA) is an organic compound, a colorless solid readily soluble in organic solvents. Its structure is characterized by a carboxymethyl substituted at position 1 of naphthalene. It is a plant growth regulator commonly used in commercial rooting powders or agents, particularly in plant propagation via cuttings. Today, we will introduce the usage and precautions for NAA.
|
|
|
Usage of NAA:
1. Wheat: Soak seeds in a 20 mg/kg solution for 10-12 hours, air-dry, and sow. Before jointing, spray once with a 25 mg/kg solution. After flowering, spray the flag leaf and panicle with a 30 mg/kg solution to prevent lodging and increase seed setting rate.
2. Rice: Soak seedlings in a 10 mg/kg solution for 6 hours. After transplanting, the seedlings will recover quickly and have strong stems.
3. Cotton: During peak flowering, spray plants 2-3 times with a 10-20 mg/kg solution, spaced 10 days apart, to prevent bud and boll drop.
4. Sweet Potato: Soak the lower part (3cm) of seedlings in a 10 mg/kg solution for 6 hours before planting to improve survival rate and increase yield.
5. Tomato and Cucurbit: Spray flowers with a 10-30 mg/kg solution to prevent flower drop and promote fruit set.
6. Fruit Trees: 5-21 days before harvest, spray the entire plant with a 5-20 mg/kg solution to prevent fruit drop.
7. Tea, Mulberry, Arborvitae, Oak, and Metasequoia Cuttings: Soak the base (3-5cm) of cuttings in a 25-500 mg/kg solution for 24 hours to promote rooting and improve survival rate.
Precautions for Naphthaleneacetic Acid (NAA):
Wash hands and face after application to prevent skin damage. Naphthaleneacetic acid (NAA) is poorly soluble in cold water. When preparing a solution, it can be dissolved in a small amount of alcohol first, then diluted with water, or mixed with a small amount of water to form a paste, then added with a suitable amount of water, followed by sodium bicarbonate (baking soda) and stirring until completely dissolved.
Difference between Naphthaleneacetic Acid and NAA-NA
NAA-NA is a plant growth regulator that rapidly promotes cell division and expansion (fruit-enlarging agent, fruit-swelling agent), induces adventitious root formation (rooting agent), and has effects such as regulating growth, promoting rooting, budding, flowering, preventing flower and fruit drop, enlarging fruits, forming seedless fruits, promoting early maturity, preventing fruit drop, enhancing color, and increasing yield. It also enhances the plant's resistance to drought, cold, disease, salinity, and hot, dry winds.
Naphthaleneacetic acid (NAA) is an auxin-like substance and a broad-spectrum plant growth regulator. It has the characteristics and physiological functions of the endogenous auxin indoleacetic acid (IAA), including promoting cell division and expansion, inducing adventitious root formation, increasing fruit set, and altering the ratio of male to female flowers. Naphthaleneacetic acid (NAA) enters the plant through the epidermis of stems and leaves and seeds, and is transported to its active sites via the nutrient flow.
NAA-NA and the sodium salt of NAA, a strong base and weak acid, hydrolyze to produce NAA. Plants utilize ions, so the presence of NAA ions is sufficient for its effect. Furthermore, NAA-NA is directly soluble in water, making its use more convenient.
Application of NAA in Rice: Soaking seeds in a 160 mg/L NAA solution for 12 hours increases the number, weight, and length of adventitious roots in rice, thus increasing tillering and yield. NAA-NA seed soaking also improves the germination rate and vigor index of rice seeds with different vigor levels, making it an effective rooting agent for rice. Applying NAA to rice seedbeds accelerates root growth and development, shortens the transplant recovery period, and improves transplant survival rate. However, the effectiveness of NAA in controlling seedling growth is only 5-6 days, requiring multiple applications for effective control. In addition, naphthaleneacetic acid can also be used in combination with regulators such as sodium nitrophenolate and indolebutyric acid. It can be used for seed soaking during rice seed treatment or for spraying during the rice growth period.
