Top Grafting Performance of Some Cocoa (Theobroma cacao L.) Clones as Affected by Scion Budwood Number

Abstract

Reducing budwood number is an efficient effort to overcome problems
related with limited scion materials. The objective of this research was to study
the effect of scion budwood number in some clones on the performance of grafted
cocoa seedlings. The research was conducted at Kaliwining Research Station,
Indonesian Coffee and Cocoa Research Institute, Jember, Indonesia at an elevation
of 48 m above sea level. Layout for this study used factorial with 2 factors in
randomized complete block design, with four replications for every treatment.
The first factor was clone type, namely MCC 02 and Sulawesi 1; whereas the second
factor was number of grafted scion budwood, namely one, two, and three grafted
budwoods. There was no interaction between clone and number of scion budwood
for variables of shoot length, stem girth, content of total chlorophyll, chlorophyll
a, and chlorophyll b. Meanwhile, there was interaction for stomatal conductance
and stomatal diffusion resistance. Clone significantly affected photosynthesis
and stomatal diffusion resistance, while number of scion budwood affected significantly
the shoot length. Photosynthesis activity of MCC 02 was higher compared
to Sulawesi 1. In average, stomatal diffusion resistance of Sulawesi 1 was higher
than MCC 02. The shoot length of one grafted budwood was higher than the
two or three grafted budwood.