Abstract: Described herein are combinatorial compositions comprising a synthetic compound and a biological agent for beneficial effect. The synthetic compound may be a leucyl-tRNA synthetase inhibitor. The synthetic compound also may be a benzoxaborole. The combinatorial compositions may have a synergistic effect. The combinatorial composition has at least one biological agent, which may have a controlling or stimulatory effect and may be selected from a modified or un-modified microorganism, metabolite, or substituent thereof. The combinatorial composition may further comprise a second modified or un-modified microorganism, metabolite or substituent thereof, or energy source for either or both microorganism(s). Also described are methods for promoting plant performance and/or curatively or preventively controlling insects, nematodes, microorganisms, or phytopathogens on or in an animal or a plant, plant parts, harvested fruits, or vegetables.