Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế, đề tài: "Use of stem diameter variations for detecting the effects of pathogens on plant water status. | Ann Sci For 1997 54 463-472 Elsevier Inra 463 Original article Use of stem diameter variations for detecting the effects of pathogens on plant water status M Cohen1 J Luque2 IF Alvarez2 1 Dep Tecnologia Horticola 2 Dep Patologia Vegetal institut de Recerca i Tecnologia Agroalimentàries IRTA Centre de Cabrils Ctra de Cabrils s n E-08348 Cahríls Barcelona Spain Received 14 June 1996 accepted 18 September 1996 Summary - Linear variable displacement transducer LVDT sensors were used on Cistus plants noninoculated or inoculated with the pathogens Botryosphaeria stevensii and Hypoxylon mediterra-neum to determine the suitability of this method to detect the effects of the infection process. Control and H mediterraneum infected plants did not differ in either the maximum daily shrinkage or the daily evolution of stem diameter. However the pathogenic effects of B stevensii were clearly detected. Daily increase in stem growth stopped 19 days after the plants were inoculated and before any noticeable external symptom. Maximum daily shrinkage occurred 5 weeks after inoculation when foliar chlorosis and stem cankers were visible and preceded the plant mortality. Stem contractions were related to the amount of daily solar radiation when stress caused by pathogens did not exist. This methodology can be useful in the study of disease development especially for those pathogens that affect the plant-water relations. Botryơsphaeria stevensii I Hypoxylon mediterraneum Cistus I pathogenic effect stem variation LVDT sensor Resume - utilisation des variations de diamètre de tige pour la detection d effets de patho-gènes sur 1 état hydrique de la plante. Le suivi des variations micromorphométriques du diamètre de tige à I aide de capteurs de déplacements linéaire LVDT a été realise sur des plantes de Cistus sains et inoculés par deux agents pathogènes differents Botryosphaeria stevensii et Hypoxykm medi-terraneum dans le but de determiner les effets éventuellement lies à I infection .
