title: Endophytic Association ofTrichoderma asperellumwithinTheobroma cacaoSuppresses Vascular Streak Dieback Incidence and Promotes Side Graft Growth.
abstract: Trichodermaspecies are able to persist on living sapwood and leaves of cacao (Theobroma cacao) in an endophytic relationship. In this research, we evaluated the ability ofTrichodema asperellumintroduced at the incision site in the bark for side grafting with the concentration of 4 g/10 mL, 4 g/100 mL, and 4 g/1,000 mL (suspended in water) in suppressing vascular streak dieback (VSD) incidence and promoting growth of side grafts in the field. The incidence of VSD in two local clones of cacao, MCC1 and M04, without application ofT. asperellumwas 71.2% and 70.1% at 21 wk after grafting, respectively. However, when the two clones were treated with a concentration of 4 g/10 mLT. asperellum, the incidence was 20.6% and 21.7%, respectively, compared to 29.1% and 20.9% at 4 g/100 mL and 18.2% and 15.6% at 4 g/1,000 mL. By comparing to the control, the treatment with the same concentrations ofT. asperellumlisted above, the total number of stomata in MCC1 decreased by 41.9%, 30.2%, and 14.0% and in M04 by 30.5%, 21.9%, and -2.5% (exception), respectively. Otherwise, the total area of stomata opening increased by 91.4%, 99.7%, and 28.6% in MCC1 and by 203.8%, 253.5%, and 35.9% in M04, respectively. Furthermore, the number of buds and branches treated with a mixture concentration on the the two clones increased by 90.7% and 21.7%, respectively. These data showed that the application ofT. asperellumto cacao scions while grafting can decrease VSD incidence in side grafts and increase growth of grafts in addition to decreasing total number of stomata, increasing total area of opened stomata, and increasing number of buds and branches.
authors: Cocoa Research Group, Faculty of Agriculture, Hasanuddin University, Makassar 90245, Indonesia.
authors: Ade
authors: A
authors: Rosmana
authors: Cocoa Research Group, Faculty of Agriculture, Hasanuddin University, Makassar 90245, Indonesia.
authors: Nasaruddin
authors: N
authors: Nasaruddin
authors: Cocoa Research Group, Faculty of Agriculture, Hasanuddin University, Makassar 90245, Indonesia.
authors: Hendarto
authors: H
authors: Hendarto
authors: Cocoa Research Group, Faculty of Agriculture, Hasanuddin University, Makassar 90245, Indonesia.
authors: Andi Akbar
authors: AA
authors: Hakkar
authors: Cocoa Research Group, Faculty of Agriculture, Hasanuddin University, Makassar 90245, Indonesia.
authors: Nursalim
authors: N
authors: Agriansyah
keywords: Branches; Buds; Endophytic relationship; Stomata opening area; VSD incidence