The use of the fungus Ascochyta caulina as a biological control agent for the weed Chenopodium album. Evaluation of the bioherbicide formulation efficacy of Ascochyta caulina on different life stages of the weed plant Chenopodium album under laboratory and field conditions comparing Libyan and UK populations.

摘要

Chenopodium album is considered one of the most important weeds adversely affectingudagricultural production due to its highly competitive influence on field crops. Chemicaludherbicides have increased the efficiency of farming, but recently problems of herbicideresistantudweed populations and herbicide residues in soil, water, food products and effectsudon non-target organisms have increased, consequently, other methods of control of weedsudby using specific fungi as herbicides have been suggested. The purpose of this research wasudto evaluate the biological control of the weed Chenopodium album by the fungus Ascochytaudcaulina. Some of the factors which control dormancy and germination of Chenopodiumudalbum seeds have been investigated to understand better the weed population dynamics.udThe results showed that seeds from two populations (UK and Libya) differ in their responseudto factors such as light, chilling, and burying in soil. This could have implications forudeffective control of the weed in different regions.udTwo formulations of mycoherbicides (Tween 80 and Gelatine based applications) wereudtested in the laboratory, and showed promise in reducing growth of the weed, especially theudformula of Tween 80. There was extensive shoot fresh and dry weight reduction ofudinoculated Chenopodium album, as well as reduced root growth. Highest disease severityudrates were observed on plants in the first three week of life. A field trial revealed similarudresults but less disease severity was observed, possibly because of dry weather. However, itudwas concluded that the fungus Ascochyta caulina is a potentially useful biological controludagent but many factors still can be modified in relation to application of the mycoherbicideudto increase its efficacy.