CONTROL OF Lasiodiplodia theobromae, THE CAUSAL AGENT OF DIEBACK OF SAPOTE MAMEY [Pouteria sapota (Jacq.) H. E. Moore and Stearn] GRAFTS IN MÉXICO

Abstract

Dieback of sapote mamey [Pouteria sapota (Jacq.) H. E. Moore and Stearn] grafts caused by Lasiodiplodia theobromae significantly reduces the success of grafting in Mexican nurseries. Semi-commercial tests were conducted in a sapote mamey nursery during two grafting seasons to evaluate the effectiveness of a physical treatment (washing) and three chemical treatments (fungicide dip) on scions. Washing reduced disease incidence up to 31 %, whereas chemical treatment reduced it up to 62 %. The combination of washing and thiabendazole dip resulted in an incidence decrease of 81 %. Twelve other fungicides were screened in vitro to evaluate mycelial growth inhibition of L. theobromae. The pre-formulated mix of cyprodinil + fludioxinil was the most effective fungicide with EC50 value of 0.0043 μg mL-1, followed by pyraclostrobin + boscalid, prochloraz and tebuconazole with EC50 values < 0.1 μg mL-1, and iprodione and thiabendazole with EC50 values < 1.0 μg mL-1. This study provides novel information about strategies for controlling L. theobromae infection during the grafting process of sapote mamey and it also showed the effectiveness of several fungicides under in vitro conditions for controlling this plant pathogenic fungus.

AKTIVITAS ANTIFUNGI EKSTRAK DAUN PICUNG TERHADAP CENDAWAN Botryodiplodia theobromae PENYEBAB MATI PUCUK BIBIT JABON MERAH Antifungal Activity of Picung Leaf Extracts Against Botryodiplodia theobromae A Dieback Fungus of Jabon Merah Seedling

“…Cendawan ini diketahui sebagai patogen tanaman berkayu khususnya di daerah tropis (Ellis et al 2007). B. theobromae menyebabkan busuk jaringan pada yam putih (Dioscorea rotundata) di Nigeria (Markson et al 2012), patogen intercrops di Ghana menyebabkan busuk jaringan pada buah coklat, mangga, pisang dan yam (Twumasi et al 2014), patogen mati pucuk pada Pouteria sapota di Meksiko (Pedraza et al (2013), dan merupakan patogen primer penyakit mati pucuk pada bibit jabon putih (A. cadamba) dengan tingkat patogenisitas yang tinggi hingga menimbulkan kematian bibit (Aisah 2014).…”

Innovations in healthy citrus garden management to reduce major pests and diseases and increase incomes of citrus farmers

“…Symptoms are characterized by yellow or foamy discharge and cracked skin due to pathogenic activity that causes stem rot. Diplodia disease or often referred to as Diplodia gummosis because it reacts to release gum [14]. Penetration causes plants to react by releasing yellow defense substances such as gummosis which are released by plants as a form of reaction after pathogen attack in tissues and are produced to localize and limit the growth of pathogens [15].…”

Perkembangan Penyakit Diplodia pada Tiga Isolat Botryodiplodia theobromae Path dan Peran Toksin Dalam Menekan Penyakit pada Jeruk (Citrus spp.)

“…Perubahan iklim sejak tahun 2009 -2010 yang cenderung basah diduga menjadi penyebab mengganasnya penyakit yang disebabkan oleh cendawan Botryodiplodia theobromae Path. (Wiyono 2011) sinonim dengan Lasiodiplodia theobromae (Pat) Griff & Maubl (Punithalingan 1980 dalam Pedraza et al 2013). Sebaran geografis penyakit ini sangat luas, lebih dari 22 provinsi, kabupaten, kota sentra jeruk (mulai dari Jawa Timur, Jawa Tengah, Jawa Barat, Bali, NTT, Sumatera, Kalimantan, dan Sulawesi (Pascapanen 2010).…”

“…Pengendalian terpadu harus dilakukan mulai dari pemeliharaan optimal, sanitasi, pengendalian hayati, pemberian fungisida yang tepat, penggunaan belerang atau bubur Bordox serta penggunaan tanaman sela dan tanaman penutup. Menanam jauh dari tanaman inang patogen B. theobromae seperti anggur (Úrbez-Torres et al 2008), mangga (Saeed et al 2011, Khanzada et al 2004, cacao, pisang, yam (Twumasi et al 2014), sapote memey (Pedraza et al 2013), dan mawar (Chen et al 2016) sangat disarankan dalam upaya menghindarkan terjadinya infeksi.…”