- Definition:
- Gibberellic acid is a natural hormone regulating the growth of plants and stimulating their growth. it is present in a natural form in most plants known to us and is used in many crops, including Thompson seedless, citrus, artichokes, pears and others.
- GA3 EXTRA: It is available in the form of tablets weighing 10 g. one tablet contains 2 g of the active substance (gibberellic)
- GA3 EXTRA: manufactured in tablet form that can be divided into 4 equal parts at the desired concentration, which makes it easier for the farmer to prepare the solution easily.
The use of GA3 EXTRA on Thompson seedless grape achieves the following benefits depending on the timing of spraying:
- Cluster elongation: Spraying the clusters with the solution leads to the elongation of the cluster, allowing finding a larger space in which the grapes grow free from crowding and reduces the vulnerability of the cluster to mold diseases or being affected by them.
- Cluster thinning: spraying clusters with the solution leads to cluster thinning by spraying at the flowering stage when 50% of the flower petals have fallen.
- Increase the size of grape berries: spraying clusters with the solution increases the size of the berries and their weight, and therefore the size of grape cluster, which leads to an increase in the total yield. Spraying is carried out during the fruit set stage and when berries reach 0.5 cm diameter.
Concentrations used in Thompson Seedless:
| Required concentration in PPM | Number of tablets used for 100 L solution |
| 10 | 0.5 tablet |
| 15 | 0.75 tablet |
| 20 | 1 tablet |
| 25 | 1.25 tablet |
Mixability: can be mixed with many pesticides, except for alkaline solutions of them.
Application rate:
| Crop | Effect | Spray timing | Application rate (ppm) | Number of tablets per 100 L water |
| Thompson seedless | Cluster elongation | When cluster reaches 10 cm | 10 | 0.5 |
| Cluster thinning | In flowering stage , when flower petals fall by 50% | 20 | 1 | |
| Sizing | In the case of homogeneous cluster: spraying once during fruit set stage and when berries reaches about 0.5 cm
In the case of non-homogeneous cluster: spraying twice, the first time when the clusters reach the fruit set stage, and the second after 10 – 15 days |
25-40
20-40 |
1.25 -2
1-2 |
|
|
Citrus (Navel orange)
|
Improving the qualities of the pericarp, delaying ripening, overcoming the phenomenon of evaporation, and resisting fruit rot
reduce the percentage of fruit falling |
When the fruit emerges and the falling flower petals percentage reaches 50-60%
Beginning of fruit set (light spray) |
10
10-15 |
0.5
0.5-0.75 |
| Mandarine | Increase the fruit set and decreasing number of seeds | When the falling flower petals percentage reaches 50-60%.
Beginning of fruit set (light spray) |
10-15 | 0.5-0.75 |
| Lemon | Delaying fruit coloration with yellow color and prolonging green color fruit life | When the fruit reaches green color stage with full size | 10 | 0.5 |
| Pear | Increase the fruit set especially in” le conte” and improving fruit specifications | When flowering reaches 70% (light spray) | 20-30 | 1-1.5 |
| Artichokes | Early harvest
Increase the yield |
When the plant forms 5 – 10 leaves (Spraying is repeated 2-3 times).
When forming the first flower head (Spraying is repeated every 3 weeks until the completion of harvesting the crop). |
20 – 30
20 – 30
|
1 – 1.5
1 – 1.5 |
| Strawberries | Early harvest | After two months of planting, there are 3 sprays between each spray and the other 15 days and the initial starts after fruiting |
20 – 30
|
1 – 1.5
|
| Bananas |
Increase the size of the finger
|
When the banana cluster is 30-40 days old and repeats again after 7-14 days |
40 |
2 |
| Peppers | Prolonging the fruiting period and improving the fruiting qualities | Spraying after Harvesting the crop with repeated spraying every 2-3 weeks | 10 | 0.5 |
| tomatoes | Promote flowering and fruit set in tomatoes infected with leafroll virus | Spraying when a viral infection appears and repeat spraying if necessary | 20 | 1 |
- Important notes when preparing the spray solution :
The required amount of tablets is dissolved in a little water, usually it takes 3-5 minutes to dissolve, and the prepared amount is added to the required amount of water.
The following shall be observed:
- It is recommended to use the prepared spray solution within 24 – 48 hours.
- Strong rainfall within 8 hours after spraying may weaken the effectiveness and in such cases spraying should be repeated.
