THE DIFFERENCES OF CNX'S COCOA SEEDLINGS
No Chupon: CNX uses wedge-side grafting method, the scion is placed at 1cm below the point of attachment of cotyledons. Therefore the trees will not have chupon, farmers don't have to manage chupon through the cycle of cocoa production (about 25 years).
Good Graft Union: The scion is grafted onto the side of the stem of the rootstock, therefore the top is retained on the rootstock to assist in moisture and nutrient uptake. This boosts the forming of the graft union and the tissues of rootstock and scion is healed strongly.
Strong Grafted Branch: With side grafting method, the time for seedlings from grafting to be ready for planting on the farm is about 3 to 4 months (while top-grafting is only 30 to 45 days), Therefore the grafted branch normally is higher than 25 cm with 6 to 8 mature leaves and looks vigorously.
Reliable Varieties: All scions were obtained from CNX’s certified cocoa budwood garden with all approved varieties by the Ministry of Agriculture and Rural Development.
OTHER SEEDLINGS
In Central Highlands, except CNX, all other nurseries apply top-grafting method. The top-grafting method has several advantages such as easy to perform; higher percentage of successfull rate, time from grafting to ex-nursery is only 30 to 45 days. All of these make the production cost of seedlings produced by top-grafting method is low. However, seedlings produced by top-grafting method have weaknesses as pointed out below:
Chupon: In top grafting, the top is removed from the rootstock and the scion shoot is grafted onto the top end of the rootstock stem. There are a number of leaf axils below the grafting point that cause chupons later on. If the chupon is not being removed early enough, it will dominate over the grafted branch and the grafted branch will die. Whenever the chupon of rootstock appears, the rootstock will give priority to feed the chupon. It is like a milk breasting mother got pregnant, the body will automatically stop producing milk in order to feed the fetus.
Weak Graft Union: Although the seedling at the time of ex-nursery looks high (about > 30 cm), but it is mainly the height of rootstock while the grafted branch is only 10-15 cm. 30 to 45 days from grafting to ex-nursery doesn’t ensure the good heal between scion and rootstock. That why when buying the top-grafted seedlings, farmers still see the plastic tape around the grafting place. If this plastic tape was remove, the grafted branch can be de-attached from rootstock during the transportation or because of wind after planting to the field. Normally, farmers were advised by nursery owners to remove this plastic tape after planting 2 to 3 months. However, farmers are busy with other things and sometime forget to do it. The plastic tape then was tied inside the trunk of cocoa tree and the tree will be collapsed after 1 to 2 years planting .
Unbalance between rootstock and grafted branch: When execute top-grafting method, the scion is normally bigger than the top-end of rootstock. This sometime lead to the unbalance between rootstock and grafted branch (picture on left). When this tree grows in the field, the rootstock is not strong enough to support the grafted branch.
Desease infected from choppon utting: The choppons normally grow very fast in rainy season and farmers have to cut choppon every month right at the rainy season. Meanwhile, the phytopthora and other deseases also spread very quickly under the humid environment. Everytime farmers cut the chuppons, the deseases will enter the cocoa trees from the cut. If the trunk of the cocoa tree were destroyed by deseases, the tree will die.
WHY NURSERIES IN CENTRAL HIGHLANDS USES TOP- GRAFTING METHOD.- Low investment for nursery infrastructure.
- Easy to perform, high rate of successful grafting, low production cost.
- Amateur -seasonal nursery business.
Almost of all nurseries in the Central Highlands are small scale household own nurseries, therefore the investment for nursery infrastructure is low. The nursery works can only start when the rainy season is finished (some years, the rainy season finished till end of November or middle of December). Thus, these nurseries only have 5 to 6 months to do everything with their nursery works from container preparation, seed sowing, grafting, seedling husbandry to having seedlings ready to be planting in the field when the rainy season comes in May or June.
Side grafting method needs at least 8 to 10 months to produce a good quality grafted seedling. Therefore, in order to have seedlings to be ready for the farms when the rains come in May or June, nursery works must start in August or September of the previous year. This time is right at the middle of rainy season in Central Highlands, therefore, to carry out nursery works, the nursery must have roofed net house to against the rains.
In order to bring the best cocoa quality seedlings to farmers, CNX has invested for a modern cocoa nursery system that includes a number of roofed net houses. The roofed net houses enable CNX to do nursery works right at the middle of the rainy season. Beside of that, the roofed net houses also protect seedlings from pests and diseases such as VSD. The VSD doesn’t has any symptom during the nursery age but it will spread and effect the trees later on in the farms. 100% seedlings that were infected with VDS in the nursery will die in the farms later on.