Colletotrichum spp. associated with agricultural crops in Malaysia, causal pathogens and potential control methods

Abstract

Colletotrichum is one of the most significant and common plant pathogens, infecting many economically important crops worldwide. Colletotrichum is also one of the most studied fungal genera in Malaysia because it contains many species that infect various types of agricultural crop including fruit, vegetable and industrial crops. Studies on Colletotrichum spp. are mostly focused on the causal pathogens, the host range and disease management. Among the host crops, most studies on Colletotrichum spp. have been conducted on infection in chilli (Capsicum spp.), which, in Malaysia, first arose in the 1980s and still continues to be a problem to this day. Studies have also been conducted on Colletotrichum spp. associated with anthracnose in fruit crops including dragon fruit, papaya, banana and mango. Disease management of anthracnose pathogens postharvest has also been conducted to prolong the shelf life of these fruit crops. In this review, Colletotrichum spp. associated with chilli and several fruit crops as well as their disease management are highlighted. There have been many changes in Colletotrichum taxonomy and systematics in recent years, affecting the identification of anthracnose pathogens reported in Malaysia. Colletotrichum species identified solely by morphology or solely via the internal transcribed spacer (ITS) region should be referred to as sensu lato (in the broad sense) since many species belong to species complexes. Species within a species complex are closely related, and most are cryptic species particularly species in the C. gloeosporioides and C. acutatum complexes which are commonly associated with agricultural crops in Malaysia. Due to the importance of Colletotrichum spp. as plant pathogens, up-to-date identification methods should be used since accurate species identification of Colletotrichum is crucial for formulating suitable disease management programmes as well as for plant quarantine and biosecurity purposes. This review provides the current knowledge on the status of Colletotrichum spp. associated with agricultural crops in Malaysia and potential control methods on different types of agricultural crops.

Review on Organochlorine Pollution in Malaysia

“…Although the current concentration of selected organochlorine pesticides does not harm human life, the use of organochlorine pesticides should be stopped in the paddy fields. Apart from Machang, Kundasan Highlands, Cameron Highlands, and Muda Scheme, which are the agricultural fields show different types and levels of organochlorine contamination [15]. The agricultural lands will be contaminated by more types of organochlorine than that in paddy fields.…”

“…The agricultural lands will be contaminated by more types of organochlorine than that in paddy fields. This might because the different plants in agricultural lands require different types of organochlorine to reduce the different types of pests [15].…”