Demucilaging Freshly Stored Seeds of Cocoa (Theobroma cacao L.) Improves Seedling Emergence and Growth

Abstract

Fresh seeds of cocoa (Theobroma cacao L.) are covered by a large amount of mucilage, which plays important ecological roles. However, for stored seeds, mucilage can adversely affect germination. This study investigated the effect of mucilage removal (demucilaging) and seed storage of freshly extracted cocoa seeds on seedling emergence and growth. The study showed that demucilaging cocoa seeds confers several advantages over mucilage intact seeds provided the seeds have been stored for at least three days before sowing. Demucilaging increased germination rate (T 50 ) and percentage germination and presence of mucilage increased days to seedling emergence and cessation of germination when seeds were stored for over two days. For up to 21 days of seed storage, there was generally no difference in many traits for demucilaged seeds. Demucilaged seeds had 80-100% germination after 21 days of storage, and rate of germination increased with increasing duration of seed storage. Intact mucilage seeds maintained 80-100% germination for only 2 days after seed extraction and rate of germination decreased with increasing seed storage duration. We conclude that (i) if seeds are sown on the day of extraction demucilaging before sowing would be superfluous and (ii) demucilaging and storage can provide advantages to smallholder farmers when environmental or socioeconomic conditions preclude immediate sowing.

Cacao Growth and Development Under Different Nursery and Field Conditions

“…In general, the best results, in terms of development of plant height, number of leaf, leaf area and percentage sprouting rate, were obtained from poultry manure mixed with sawdust and topsoil growing media whose cacao seeds were cleaned with water or cloth. This was a result of ease of sprouting in the absence of the mucilage coat on the seeds which was in conformity with the findings of [16].…”

Implications of Cocoa Pod Storage and Temperature to the Performance of Pod Components and Seedling Growth

“…The pulp plays important role in delaying seed germination inside the pod. The pulp has functions to stabilize the water potential around the seeds and prevent them from drought stress during storage (Adu et al, 2017). Storing cocoa pod at high temperatures for relatively long time causes drying of the pulps faster, so the deterioration of the seeds is also faster.…”

Effect of Placenta and Fermentation Duration on Drying Dynamics of Cocoa Beans in a Tropical Environment

“…Th is could probably be due to mo isture ava ilab il ity prov ided by placenta and shorter days in fermentat ion. Adu et al [29] stated that cocoa mucilage together with its placenta consists of about 87% water content.…”

“…Cocoa beans dr ied w ith placenta had the h ighest rate of mo isture reabsorpt ion. Th is could be due to the presence of placenta wh ich served as mo isture reservo ir [29] for the beans wh ich had already lost some amount of mo isture due to its hygroscop ic nature [14]. Garg et al [30] revealed in their study that, a product's res istance to internal mo isture loss depends on its hygroscop ic and collo idal propert ies as well as the s ize of the pores, wh ich govern the cap illary movement of flu id.…”