MSc

A study on the different aspects of propagation of cocoa was undertaken at the College of Horticulture from May 1978 to July 1979 to standardise the criteria for selecting the pods, seeds and seedlings for raising the nursery, to find out the optimum size of polythene bags and the suitable medium for raising the nursery and also to standardise the best vegetative propagation methods for cocoa.
The results had indicated that the volume and weight of the pods varied within the three classes of pods namely large, medium and small. There was not much variation in the number of seeds among the three classes of pods and the mean number varied between 30 to 42. The number of seeds were found to be highest in pods harvested in February and March followed by April. The highest percentage of germination was recorded in March followed by February, January, December and April.
The size of the pod and the position of seeds (pedicel end, middle and distal end) had no significant influence on the germination and the growth of the seedlings. However, the large and medium sized pods are found to produce better seedlings. Based on the studies the following recommendation are made i) Large and medium sized pods weighing more than 350g each with not less than 400 cc volume should be selected for raising the nursery during the month of February and March. ii) The seed should be sown on the same day of harvest but it can be stored under room conditions upto six days. The percentage of germination will be decreased to 66 per cent by the sixth day. iii) A selection criterion for selecting the seedlings when they are three months old is recommended. The seedlings should have atleast 30cm height and 10 or more number of leaves when they are three months old.
For raising three to five month old seedlings, the optimum size of bag is found to be 30 x 20 cm and the best medium for raising cocoa nursery is a mixture soil, sand and farm yard manure in the proportion 1:1:2.
Considering the pattern and extent of root and shoot growth of the seedlings, planting the seedling when they are three to four months old is suggested.
For higher percentage of rooting and optimum number of roots and higher root length, a ‘quick dip’ method for 60 sec in 4000 ppm NAA or 6000 ppm IAA is recommended for producing rooted cuttings. A ‘mist chamber’ method is suggested for rooting the cuttings.
Forkert method of budding is recommended for cocoa either on eight to nine months old root-stocks or by green budding on three to four months old root-stock. The best time for budding is February and March on older root-stocks and April and May for green budding.