ICAR-Growth and yield performance of Trinidad cocoa ( Theobroma cacao L.) collections in Karnataka

CPCRI, Regional Station, Vittal, Karnataka at a spacing 2.7 m x 5.4 m under 2.7 m x 2.7 m spaced arecanut garden. Five trees each of these clones were considered as individual replication and observed for their growth parameters at the age of nineteen years. The annual pod yield was compiled for six years, from fourteenth to nineteenth year of bearing. Individual pod characters were measured from five pods of each clone harvested during the main season of June to August. Processed, fermented and dried beans were observed for bean characteristics in 100 beans from each clone. Fat content in the bean was estimated by petroleum ether extraction method using Soxhlet apparatus and expressed in percentage. Data were analysed using MSTAT program. Among the Trinidad collections studied, significant difference was observed for all the growth characters. Plant height ranged from 3.2 to 4.6 m and vigour with respect to girth of stem ranged from 34.2 to 53.4 cm. Canopy of the trees spread to an area of 15.0 to 22.5 m 2 with 6.2 to 12.4 branches (Table 1) among the clones. The height at first branching, number of branches and canopy area were maintained with systematic annual pruning to make cocoa compatible and manageable in the intercropping system under arecanut and to enhance the pod production as suggested by Thomas and Balasimha (1992).

Cocoa is an important industrial and beverage crop of the world, famous for its produce, the beans, which are the only source for chocolates. Various genotypes contribute to the economic cultivation of cocoa in the major producing countries of south and central America, Africa and Asia. In India, selective collections from Malaysia and Nigeria constituted the old plantations and later many introductions were made from Amazon, Ghana, Peru and Trinidad. Cocoa is classified into three basic types Criollo, Forastero and a natural hybrid between these two, the Trinitario (Wood and Lass, 1955) which is said to have evolved from Trinidad. These clones comprise mixed characteristics and are well adapted to different growing zones. It is estimated that around 90 per cent of the world's current cocoa population is comprised of Forasteros and Trinitarios (Eskes and Lanaud, 2001). In Ivory Coast, which stands first in cocoa production, hybrids between upper Amazon Forastero and Trinitario clones are very popular due to their vigour, precocity, productivity and bean quality (Tahi et al., 2012). The major cocoa producers of Asian region, Malaysia and Indonesia are also widely cultivating Trinitarios for their quantitative and qualitative parameters (Amores et al., 2009;Anita-Sari and Agung, 2013). With this background, en effort was made to assess the Trinidad collections conserved by ICAR-CPCRI for its cropping efficiency in arecanut garden and to identify potential clones to be utilised in area expansion programs.
Thirteen Trinidad or true Trinitario collections were planted during 1995 and conserved at ICAR-Growth and yield performance of Trinidad cocoa (Theobroma cacao L.) collections in Karnataka S. Elain Apshara ICAR -Central Plantation Crops Research Institute, Regional Station, Vittal-574 243, Karnataka, India (Manuscript Received:19-05-2015, Revised:10-06-2015, Accepted:13-08-2015 Keywords: Clones, cocoa, dry beans, pod yield, Trinitario *Corresponding Author: elain_apshara@yahoo.co.in CPCRI, Regional Station, Vittal, Karnataka at a spacing 2.7 m x 5.4 m under 2.7 m x 2.7 m spaced arecanut garden. Five trees each of these clones were considered as individual replication and observed for their growth parameters at the age of nineteen years. The annual pod yield was compiled for six years, from fourteenth to nineteenth year of bearing. Individual pod characters were measured from five pods of each clone harvested during the main season of June to August. Processed, fermented and dried beans were observed for bean characteristics in 100 beans from each clone. Fat content in the bean was estimated by petroleum ether extraction method using Soxhlet apparatus and expressed in percentage. Data were analysed using MSTAT program. Among the Trinidad collections studied, significant difference was observed for all the growth characters. Plant height ranged from 3.2 to 4.6 m and vigour with respect to girth of stem ranged from 34.2 to 53.4 cm. Canopy of the trees spread to an area of 15.0 to 22.5 m 2 with 6.2 to 12.4 branches ( Table 1) among the clones. The height at first branching, number of branches and canopy area were maintained with systematic annual pruning to make cocoa compatible and manageable in the intercropping system under arecanut and to enhance the pod production as suggested by Thomas and Balasimha (1992).
The average pod yield (six harvests per year) was compiled from fourteen to nineteen year old tress and observed for stable and high yielders.  With more than 50 pods tree -1 year -1 , the clones VTLC-351, VTLC-345, VTLC-357 and V T L C -3 5 0 w e r e t h e p r o m i s i n g y i e l d e r s identified in the arecanut based intercropping system.
Pod characteristics of cocoa collections are tabulated in Table 3. VTLC-144 produced small pods and VTLC-144 had bigger pods, as measured by length and breadth and shape of pods for description of clones (Turnbull and Eskes, 2010).
It is considered optimal to have 350 g pod weight to ensure pod filling with >35 beans as a selection criteria for mother trees (Vikraman Nair et al., 2000). The husk:bean ratio ranged from 1.8 to 4.3 and an optimal husk:bean ratio of 3 is considered advantageous for more bean recovery. The ridge and furrow thickness of clones ranged from 0.9 to 1.3 and 0.7 to 1.1 respectively. Though less than one centimetre, husk thickness is being used as selection criteria, 1 cm and above is considered as advantageous in preventing spread of pod rot to beans and damage by boring insects, if the average bean number is 35 and above. Among the pod characters, number of beans per pod contributed much to the economic yield of the crop which ranged from 35.2 to 52.8. Interestingly, all the Trinidad collections irrespective of their pod sizes had the average bean number of 35 which is common in Trinitarios (Wood and Lass, 1955;Anita-Sari and Agung, 2013).
Other bean traits showed a positive estimate of wet:bean ratio in the range of 2.1 to 3.2 among the clones (Table 4). The high bean index of single dry bean weight of 1 gram and above was obtained in four clones, VTLC-135, VTLC-141, VTLC-147 and VTLC-140 in the order of 1.20, 1.13, 1.02 and 1.00 g, respectively. Trinidad Selected Hybrids (TSH), which have low pod index, large beans and good disease resistance with optimal management (Maharaj et al., 2009;Maharaj, 2012), were the main component of cocoa economy of Trinidad and Tobago. The Trinidad collections studied also exhibited comparatively larger bean size of 0.9 to 1.2 g. Dry bean yield was further compiled with the mean pod number per tree, bean number per pod and single dry bean weight which showed a range of 1.2 to 3.1 kg tree -1 . Processing value regard to shelling percentage, nib recovery and fat contents were also assessed for their industrial suitability. Based on the overall performance and important characteristics, potential clones were selected from this trial and listed in Table 5, along with their desirable traits.
From the growth and yield parameters assessed over years in the Trinidad collections, VTLC-351, VTLC-345, VTLC-357 and VTLC-350 were identified as high and potential yielders with 3.1, 3.0, 2.3 and 2.1 kg dry bean yield per tree, respectively. These clones exhibited optimal vigour and canopy area in the intercropping system under arecanut. With single bean weight of more than 1 gram, 13-15 per cent shelling, 84-87 per cent nib recovery and >50 per cent fat, these true Trinitarios were found to be suitable for chocolate industry. These selected cocoa clones can be used for commercial cultivation. However, further evaluation trials under coconut canopy and in multiple locations are required to confirm the growth performance and yield sustainability in cocoa.