A complex coacervate formulation was developed for Colletotrichum truncatum 00-003B1 (Ct), a bioherbicidal fungus against scentless chamomile, and tested in the greenhouse. A two-step process was developed to formulate Ct conidia: (1) invert emulsion preparation—emulsify an aqueous suspension of Ct conidia in nonrefined vegetable oil with the aid of a surfactant, and (2) encapsulate the Ct conidia invert emulsion by complex coacervation. Formulation ingredients, including nonrefined vegetable oils, surfactants, proteins, and carbohydrates, and formulation-processing parameters, including mixing speed and the amount of oil added to invert emulsions, were examined for maximum retention of Ct conidia in the formulation. Most formulation ingredients considered and tested in this study were compatible with Ct, with no significant reduction in conidial germination and mycelial growth. The surfactant soya lecithin promoted the greatest retention of Ct conidia (88%) in the invert emulsion, followed by sorbitan monooleate (82%), glycerol monooleate (70%), and sorbitan trioleate (55%). Optimal retention of Ct conidia in the invert emulsion was observed with a water ∶ oil ratio of 1 ∶ 1.8 to 1 ∶ 3.7, and an overhead paddle stirring speed of 300 rpm when preparing the emulsion. Complex coacervate wall ingredients of 1% gelatin and 2% gum arabic were most effective for Ct conidia retention. In greenhouse studies, scentless chamomile disease rating, following a 24-h dew period, was higher on plants sprayed with the Ct conidia complex coacervate formulation than on plants with Ct conidia suspended in 0.1% Tween 80.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 24 • No. 2