Variability of survival and yield traits in cacao (Theobroma cacao L.) clones under marginal field conditions in Ghana

ABSTRACT

Increasing the genetic base of current parental cacao varieties grown in West Africa with clones that are able to perform well under marginal conditions could improve cacao production. Survival and yield of 30 different cocoa clones of more recent introductions were compared with five parental clones of improved cocoa varieties under natural field conditions in Ghana. A randomized complete-block design with five replications was used to evaluate the 35 clones for the following traits: percentage survival, increase in trunk cross-sectional area (TCSA), canopy spread, bean mass and bean yield. Significant (p < 0.05) clone effects for all traits and broad-sense heritability range of 0.16–0.51 were observed. Bean mass and bean yield varied from 0.90 to 1.44 g and 149 to 467 kg/ha, respectively. Bean yield and TCSA was positively and moderately correlated (r = 0.46; p < 0.01). Clones A 1/197, ICS 70 and MO 20 outperformed the best control clone for both survival and yield, which could be used in cacao breeding to improve production under marginal conditions in Ghana.

KEYWORDS:

• Bean mass
• broad sense heritability
• cocoa establishment
• germplasm
• improved varieties
• tree vigor

Acknowledgements

The authors gratefully thank the field and technical staff of the Plant Breeding Division, CRIG, for their support and assistance, especially Mr. Robert Dorbgadzi and Mr. Amoako for their support and assistance. This work is published with the kind permission of the Executive Director of Cacao Research Institute of Ghana as manuscript number CRIG/03/2017/024/007.

Data archiving statement

The mean performance of all 35 clones for increase in TCSA in the juvenile stage, percent survival (%S), canopy spread, bean mass and bean yield are indicated in the SI table.

Supplemental data

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