Citrus stem rot disease (Lasiodiplodia theobromae (Pat.) Griff. & Maubl) problem and their control strategy in Indonesia

Abstract

Citrus stem rot disease caused by Lasiodiplodia theobromae (Pat.) Griff. & Maubl is a serious disease in citrus orchards in Indonesia. The geographical distribution of these diseases is very broad, almost found in all citrus centers of more than 22 provinces, districts, and cities. Plants of more than 10 years with less intensive maintenance often seriously affected. Alertness and control must be more intensive in productive plants aged more than 5 years old. The disease epidemic problem occurs because of the presence of sensitive citrus varieties, poorly maintained plants, the source of inoculum throughout the year, wide range of host plants, and contamination of agricultural equipment. Sensitive plants in citrus genus including pummelo, orange, tangerine, lime, and lemon. The control strategy is formulated by considering the effectiveness, logical and environmentally friendly to support the development of citrus areas in 24 main citrus centers in Indonesia. Stem rot control strategies include: (1) monitoring of disease incidents in the field, presence of inoculum sources in citrus plants and other hosts, (2) maintaining the cleanliness of the field, sanitation by pruning the branches, (3) optimum maintenance, (4) disinfecting agricultural tools (pruning shears, grafting knives, machetes, saws) with 70% alcohol, (5) Weaning of stems with sulfur lime 2 times a year, (6) Biological control (Trichoderma harzianum, T. asperellum, T. viride, Bacillus subtilis, Gliocladium sp) and or botanical control using cashew nut shell waste (Anacardium occidentale L.), red ginger extract (Zingiber officinale var. rubrum).