Cucurbitaceae family consists of medium-sized, warm-season vining plants that are mostly found in the tropical region of the world including Nepal and India. When left to its natural growth habit, it produces a large number of flowers on its branches and it leads us to believe that the plant will give us a higher yield. But does having a large number of flowers always guarantee a higher fruit set and higher yield? Of course not. It depends upon many factors such as environment, nutrition, irrigation, flowering habits, and so on.
Most of the members of the family Cucurbitaceae are monoecious i.e. they produce male and female parts on separate flowers but the same plant. The number of the fruit set and ultimately the yield depends upon the ratio of male to female flower which in the case of fully grown cucurbits, is 25:1 to 15:1. Since it is the female flower that gives us fruit, this low male-to-female flower ratio is responsible for low yield even though the total number of flowers (male+female) is comparatively high. This problem, in recent times, has been exaggerated by the rapid decline in beneficial insects and pollinators due to the haphazard use of chemical pesticides by our farmers.
So, the obvious solution is to increase the number of female flowers and bring down the ratio of male to female flowers in a cucurbit plant. Well, that’s where 3g cutting comes into play.
Before we get into 3g cutting, we have to first know generation of a branch. Following seed germination, only one main branch continues to grow referred to as 1st generation or primary branch. This primary branch gives rise to another branch known as 2nd generation or secondary branch. Furthermore, as 2nd generation branch gives rise to another branch, it is referred to as 3rd generation or tertiary branch.
1st and 2nd generation branch harbors a large number of male flowers and very few female flowers in them ( male to female = 14:1). That’s why the fruit set is very low despite heavy flowering. On the other hand, 3rd generation branch boasts a much higher number of female flowers in comparison to 1st and 2nd generation branches.
A normal cucurbit plant has one 1st generation branch, many 2nd generation branches, and very few numbers of 3rd generation branches. So, the obvious solution would be to increase the number of 3rd generation branches that has higher number of female flower which would ensure higher fruit set and yield (given that proper pollination and nutrition is provided). And that’s exactly what 3g cutting does.
3g cutting is a technique that promotes the growth of 3rd generation (tertiary) branch by pruning and trimming the tip of 1st and 2nd generation branch. Promoting the growth of 3rd generation branch intensifies the number of female flowers, balances the number of male and female flowers in the plant, and ensures a higher yield.
Male to female flower ratio ( before 3g cutting ) : 15:1
Male to female flower ratio ( after 3g cutting ) : 1:2
Thus, a great increase in the number of female flowers is seen and fewer male flowers can still pollinate large number of female flowers.
Plant compatible for 3g cutting
This technique is quite popular and successful in the Cucurbitaceae family but it can be performed in other crops as well.
Here is a list of the plants in which 3g cutting is successful.
- Bottle gourd
- Ridge gourd
Procedure of 3g cutting
1.The main branch from the seed should be allowed to grow up to a height of 7-8 ft (2.1 -2.5m) in case of gourd or 5-6 ft (1.5-1.8m) in case of cucumber and pumpkins.
2.Then the tip of the main branch after reaching desired height should be cut off. This will break the apical dominance of the main branch and promote the growth of secondary or 2nd generation branches.
3.The secondary branches should be allowed to grow up to 2-3ft (up to 12 leaves) keeping their number up to 3-4.
4. After the secondary branches reach the length of 2-3ft or 12 leaves, then their tip should be cut off which will promote the growth of tertiary branches.
5. Now the third generation branches should be allowed to grow with proper fertilization and adequate nutrients.
- No side branch should be allowed to develop from the lower 5-6 branches as there is no production of female flowers.
- Before five leafed stage, no side branches should be allowed to develop. This makes the base strong.
- The soil should not be dry during 3g cutting. The soil should be at field capacity.
- The plant should be kept in proper sunlight.
- The number of secondary branches should be kept 4-5, otherwise, the plant will be bushy, sunlight cannot enter properly and the fruits will be small. If necessary further trimming should be done after 3g cutting.
- Proper nutrition and pollination have to be taken care of. In the case of rooftop farming or the absence of natural pollinators such as bees, ants, etc, hand pollination should be done.
Pros and cons of 3g cutting
- Exponentially increase our production
- Higher yield and income per plant and per unit area of land.
- Improvement in the size and quality of the fruit
- Elongates the vegetative phase of the plants and delayed flowering and fruiting in comparison to normally grown plants
- Needs good technical knowledge to carry out.
- Chances of disease and fungal infection at the site of trimming.