TITLE:
Enhancement of Theobroma cacao Seedling Growth and Tolerance to Phytophthora megakarya by Heat-Treated Oyster Shell Powder
AUTHORS:
Tene Tayo Paul Martial, Dzelamonyuy Aristide, Omokolo Ndoumou Denis, Boudjeko Thaddée
KEYWORDS:
Cocoa, Seedling, Phytophthora megakarya, Oyster Shell, Biofungicide
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.10 No.4,
April
23,
2019
ABSTRACT: The aim of this study was to
evaluate the ability of oyster shell powder soil amendment to enhance cocoa
seedling growth and induce resistance against Phytophthora megakarya in nurseries. The
results showed that heat-treated oyster shells powder at 1% (w/w) soil
amendment significantly increased plant height, leaf number, leaf area, dry
shoot and root weight more than chemical fungicide and control treatment after
twelve weeks of growth. The results showed that heat-treated oyster shell
powder raised soil pH significantly and reduced P. megakarya load of the soil suspension by 82%. Assessment of
resistance stimulation by leaf inoculation showed the highest level of
resistance recorded in plants treated either with heat-treated or non-treated
oyster shell powder. Furthermore, total phenolic compounds contents, total
soluble proteins contents, polyphenoloxidase, chitinase, peroxidase and β-1,3-glucanases activities increased in
both healthy or infected leaves from cacao plants treated with oyster shell
powder more than those treated with chemical
fungicide. These findings demonstrated that heat-treated oyster shell powder could be used as biofertilizer and
biofungicide to improve the quality of cocoa seedling production and protect
the plant against P. megakarya.