The application of Plant growth hormone to economic crops -- Tea plantation

1. Promote rooting of tea tree cuttings
Naphthalene acetic acid(NAA)
Use 60-100mg/L solution to soak the base of the cuttings for 3-4 hours before inserting.  In order to improve the effect, you can also use a mixed solution with a concentration of α-Naphthalene acetic acid (NAA) 50mg/L + IBA 50mg/L, or α-Naphthalene acetic acid (NAA) 100mg/L + vitamin B, 5mg/L mixed solution.

Indole-3-acetic acid (IBA)
Before inserting, use 20-40mg/L solution and soak it in the 3-4 cm length of the base of the cuttings for 3 hours.  However, IBA is easy to decompose when exposed to light, so medicines must be packaged in black and stored in a cool, dry place.

2.  Promote the germination of tea buds
Gibberellic Acid GA3
The yield-increasing effect of Gibberellic Acid GA3 is mainly due to its ability to promote cell division and elongation, thereby promoting bud and leaf germination, stimulating and accelerating the growth of new shoots.  After spraying in leaf tea gardens, dormant buds are stimulated to germinate and grow rapidly, the number of buds and leaves increases, the pinching of leaves is reduced, and the tenderness is good.  

According to experimental measurements by the Tea Science Institute of the Chinese Academy of Agricultural Sciences, the density of new shoots is 10%-25% higher than that of the control.  The yield of spring tea generally increases by about 15%, that of summer tea by about 20%, and that of autumn tea by about 30%.
Injecting 10-40 mg/L gibberellic acid into the petioles of unbranched young tea trees can break dormancy.  The tea trees will grow 2-4 leaves by mid-February, while the control tea trees will not start growing leaves until early March.

3.  Promote the growth of tea buds
Compound Sodium Nitrophenolates (Atonik)
After spraying 1.8% Compound Sodium Nitrophenolates (Atonik) aqueous agent, tea trees showed a variety of physiological effects.
First, the distance between buds and leaves was elongated, and the bud weight increased.  It was measured that the bud weight increased by 9.4% compared with the control;
The second is to stimulate the germination of adventitious buds, and the germination density increases by 13.7%;
the third is to increase the chlorophyll content, improve photosynthesis capacity, and make the leaves greener.  

According to the average of the two-year test, spring tea production increased by 25.8%, summer tea production increased by 34.5%, autumn tea production increased by 26.6%, and the annual average production increase was 29.7%.
The commonly used dilution factor in tea gardens is 5000 times, every 667m⊃2;  use 12.5mL of the original solution and add 50kg of water for spraying.

4.  Inhibit the formation of tea seeds
Ethephon
Tea trees are cultivated in order to harvest more of their young shoots.  Therefore, for leaf-harvesting tea gardens, applying growth regulators to control the growth of flowers and fruits and promote the growth of buds and leaves is an effective way to increase tea production.

The mechanism of action of Ethephon on tea trees is to promote the activity of abscission cells in flower stalks and fruit stalks to achieve the purpose of shedding.  Due to the reduced consumption of nutrients by flowers and fruits, tea production can increase by 16.15% in the next year.  Generally, the spraying concentration is 800-1000 mg/L.

Since the release of Ethylene molecules accelerates as the temperature increases, the concentration should be appropriately lowered when the flower buds are small, the tissue is vigorously growing, or the temperature is high.

When most flowers have opened, the growth is slow, or the temperature is low, the concentration should be appropriately high. Spraying from October to November will have the best effect of removing flowers and fruits and increasing yields.

5.  Accelerate the growth of seeds and seedlings
Seed propagation is one of the important ways to propagate tea seedlings.
The application of plant growth substances such as α-Naphthalene acetic acid (NAA), Gibberellic Acid GA3 and other treatments can promote seed germination, develop young root systems, grow quickly and strong, and leave the nursery early.

a-Naphthalene acetic acid (NAA)
Soak tea tree seeds in 10-20 mg/L Naphthalene acetic acid (NAA) solution for 48 hours, then rinse with water before sowing.  The seeds can be unearthed about 15 days earlier and the seedling stage can be earlier by 19-25 days.

Gibberellic Acid GA3 
Soaking tea seeds with 100mg/LGibbellic Acid GA3 liquid for 24 hours can speed up the emergence of seedlings.

6.   Increase tea yield
1.8% Compound Sodium Nitrophenolates (Atonik) Tea tree fresh leaf yield depends on germination density and 100 bud weight.   Tests have shown that the germination density of tea trees treated with 1.8% Compound Sodium Nitrophenolates (Atonik) at each concentration is more than 20% higher than that of the clear water control.   The new shoot length, new shoot weight and the weight of one bud, three leaves and one hundred buds are also significantly better than the clear water control.   The yield-increasing effect of 1.8% sodium nitrophenolate aqueous solution is excellent.   The yield-increasing effect of different concentration treatments is best with 6000 times solution, and 3000-6000 times solution is usually used.

1.8% Compound Sodium Nitrophenolates (Atonik) aqueous solution can be promoted and used as a commonly used variety of tea trees in tea areas.   The appropriate concentration is 3000-6000 times of solution, 667m⊃2;   the spraying volume is 50-60kg.

Brassinolide(BR)
Spraying 0.01% Brassinolide (BR) diluted 5000 times can promote the growth of tea tree buds and leaves, increase the density of buds, and increase the yield of buds and leaves.   It can also increase the yield of fresh leaves by 17.8% and dry tea by 15%.   The yield increase effect is obvious.

Ethephon
tea trees consume a lot of nutrients and energy to bloom and bear fruit.   Spraying 800 mg/L Ethephon from late September to November can have a good effect on reducing flowers and fruits.

Chlormequat Chloride (CCC)
Chlormequat Chloride (CCC) can enhance reproductive growth, increase the fruit setting rate and tea fruit yield of tea trees, which has application prospects for improving certain tea tree varieties with very low fruit setting rates, as well as tea gardens for the purpose of harvesting tea seeds.   Treating tea trees with 250mg/LChlormequat Chloride (CCC) and 500mg/LChlormequat Chloride (CCC) can increase tea fruit yield by 68%-70%.

Gibberellic Acid GA3
Gibberellic Acid GA3 can promote cell division and elongation.   The study found that after treatment with Gibberellic Acid GA3, the dormant buds of tea trees sprouted and grew rapidly, resulting in an increase in bud heads, relatively reduced leaf pinching, and the tea leaves remained tender, creating conditions for increasing tea production and improving quality.   Gibberellic Acid GA3 should be sprayed on the leaves at 50-100 mg/L during the initial development of tea buds and leaves in each season.

Adjust tea picking period
The new shoot elongation of tea trees has a strong synchronization reaction during the spring tea period, resulting in a concentrated peak period of spring tea and prominent contradictions in harvesting and production.   

Gibberellic Acid GA3 and some growth regulators are used to promote the synthesis and transformation of proteins and sugars, accelerate cell division and elongation, accelerate the growth rate of tea trees, and make new shoots grow in advance;   some growth regulators can also be used to inhibit cell division and elongation.   

Based on the long-term principle, it acts as a retardant to delay the peak period of the flood, thereby adjusting the tea picking period and easing the labor usage contradiction of manual tea picking.

Gibberellic Acid GA3
Evenly spraying 100mg/LGibbellic Acid GA3 liquid can make spring tea be mined 2-4 days in advance, and summer tea can be mined 2-4 days in advance.

α-Naphthalene acetic acid (NAA)
α-Naphthalene acetic acid (NAA) can be sprayed with 20mg/L liquid and can be picked 2-4 days in advance.

Ethephon
Spraying 25mg/LEthephon solution can make spring tea germinate 3 days in advance.