PERKEMBANGAN PENGENDALIAN PENYAKIT VASCULAR STREAK DIEBACK PADA TANAMAN KAKAO / Current Research Progress and Strategy to Control Vascular Streak Dieback (VSD) Disease of Cacao

Abstract

<p><em>Vascular streak dieback</em> (VSD) merupakan penyakit penting pada tanaman kakao. Penyakit ini telah berkembang luas di sentra produksi kakao di Indonesia dan menyebabkan kerugian 30-45% dari produksi. Luas serangan VSD di Indonesia pada tahun 2007 adalah 70.000 ha dengan kehilangan hasil sebesar Rp 405 643 680 000/tahun, dan kerugian terus meningkat dari tahun ke tahun. Tujuan dari revieu ini adalah menginformasikan tentang penyakit VSD dan perkembangan teknologi pengendaliannya. Penyakit VSD adalah penyakit pembuluh kayu yang menyerang tanaman kakao. Gejala serangan ditunjukkan oleh daun yang mengalami klorosis, gugur dan meranting, hingga akhirnya tanaman tidak berproduksi. Penyakit VSD disebabkan oleh cendawan <em>Ceratobasidium theobromae, </em>yang bersifat obligat parasit, tersebar melalui spora udara (basidiospora), melalui bahan tanam atau bibit kakao yang telah terinfeksi. Keberhasilan spora untuk berkecambah dan melakukan penetrasi jaringan daun sangat tergantung pada kondisi lingkungan. Karakteristik <em>C theobromae </em>yang sulit diperbanyak pada medium buatan menjadikan penelitian VSD sangat tergantung dengan kondisi inokulum di lapang. Komponen pengendalian yang telah dikembangkan berupa varietas atau klon kakao tahan VSD, aplikasi fungisida, agens hayati dan kultur teknis. Pengembangan kakao tahan VSD perlu disertai dengan pengembangan komponen teknologi pengendalian lainnya. Penanaman klon tahan VSD disertai dengan penerapan kultur teknis budidaya kakao yang tepat disertai aplikasi komponen pengendalian yang sesuai dianggap sebagai strategi untuk menekan penyebaran VSD yang efisien, efektif dan ramah lingkungan. .</p><p> </p><p align="center"><strong> </strong></p><p align="center">ABSTRACT</p><p>Vascular Streak Dieback (VSD) is a main disease in cacao. It has been widely spread in cacao producing centers in Indonesia which has caused 30-40% production loss. Infested plant showed symptoms such as clorosis on its leaves which then fall off and die back. eventually stop producing. VSD is caused by a obligate<em> </em>parasite<em> </em>fungus<em> </em><em>Ceratobasidium theobromae </em>, , spread through basidiospora, plant materials, or infected seedlings. Since this fungus is difficult to be cultured in artificial media causes the research on VSD highly depends on the availability of inoculum at the field The ability of spora to germinate and penetrate leaves tissue is determined by environment conditions. Components of control which have been developed are varieties or cacao clones, fungicide application, biocontrol agents, and technical culture. Developing VSD resistant cacao also necessitates the development of control technology components. Planting VSD resistant clones combines with sugested cultural practices are considered efficient and effective for controlling VSD as well as an environmental friendly control strategy.</p><p> </p>

In vitro growth induction of Ceratobasidium theobromae, the causal agent of cacao Vascular Streak Dieback disease

“…Total DNA extraction of the fungus C. theoromae was carried out using a conventional method [17] and followed by a DNA purification method following the DNA purification kit protocol (Thermo scientific). Target DNA amplification using specific primers ITS1 and ITS2 [5,12]. PCR amplification using specific primers ITS1 and ITS2 resulted in DNA fragments of approximately 550 bp in size.…”

“…Several VSD disease control techniques have been developed, including the use of resistant varieties, technical culture, botanical pesticides, biological control and the use of synthetic fungicides, induction of resistance, and others [12]. However, these control techniques are not effective enough to control VSD disease in the field.…”

Effectiveness of Trichoderma spp. secondary metabolites formulation in controlling vascular streak dieback of cacao

“…Vascular Streak Dieback is a disease of woody vessels in cacao plants caused by Ceratobasidium theobromae [4]. VSD disease is widespread in almost all cacao production centers in Indonesia considerable losses because it causes plant death [5,6]. The VSD disease can reduce yields by 30%-45% [7].…”

The Role of Leaf Nutrients in Vascular Streak Dieback Disease in Cocoa Plants (Theobroma cacao L.)

“…The increasing severity of the disease over time is associated with environmental and climatic changes (Delgado-Ospina et al, 2021). The symptoms of VSD intensify during the dry season because the pathogen attacks the vascular system, leading to impaired water and nutrient supply to the leaves and resulting in branch dieback and leaf shedding (Harni et al, 2019). To anticipate these climate changes, plants must always be in a high-vigor condition through a proper and balanced supply of nutrients, enabling them to adapt and withstand environmental stress and pathogen attacks.…”