Formulation development of the deleterious rhizobacterium Pseudomonas trivialis X33d for biocontrol of brome (Bromus diandrus ) in durum wheat

Abstract

Aim: To develop an appropriate formulation of the deleterious rhizobacterium Pseudomonas trivialis X33d and to evaluate its effectiveness to reduce brome growth. Methods and Results: Two formulations of Ps. trivialis X33d, a semolinakaolin granular formulation (Pesta) and talc-kaolin powder, were prepared and their effectiveness in reducing brome growth was evaluated. Both brome suppression and cell viability of X33d were higher in Pesta granular formulation than in talc-kaolin powder one. The impact of storage temperature and the addition of adjuvants (sucrose and oil) to the granular formulation of X33d were assessed in order to improve the shelf life of the formulation. The longest viability was found in formulated product supplemented with adjuvants and stored at 4°C. The effect of Pesta granules supplemented with adjuvants and stored for 6 months at 4°C on brome and wheat growth under controlled and greenhouse conditions was evaluated. The X33d formulation in Pesta increased the growth of wheat and reduced brome growth. Conclusion: Our results indicate that Ps. trivialis X33d formulated in Pesta has potential as a bioherbicide to control brome. Significance and Impact of the Study: Because of the impracticality of applying bacterial cell suspension on a large scale, the use of Pesta granules of X33d against brome could help in achieving a sustainable agriculture application of a bioherbicide.

Agricultural Applications of Microbes

“…Pseudomonas trivalis X33D is a promising biocontrol agent against great brome ( Bromus diandrus ) in durum wheat. This strain when formulated reduced the growth of brome and increased the growth of wheat (Mejri et al 2013 ) …”

Zeolite-based, dry formulations for conservation and practical application ofParaburkholderia phytofirmansPsJN

“…), sucrose and oil (Mejri et al . ). These fulfil a variety of tasks such as nutrient provision, improvement of physical characteristics and protection of bacterial cells.…”

“…Frequently, the carrier materials are amended with adjuvants such as wheat bran (M€ uller-St€ over et al 2004), glycerol, carboxymethylcellulose (CMC) (Sarma et al 2011), glucose, rice bran (Anandham et al 2007), maltose, lactose (Daigle et al 2002), sucrose and oil (Mejri et al 2012). These fulfil a variety of tasks such as nutrient provision, improvement of physical characteristics and protection of bacterial cells.…”

Effect of bioformulations on the biocontrol efficacy, microbial viability and storage stability of a consortium of biocontrol agents against Fusarium wilt of banana

“…In general, the stability of a microbial formulation can be expected to last from 6 months to a year (Berninger et al 2018). The use of additives and lower storage temperatures are common factors that determine the stability of BCAs in long-term storage (Mejri et al 2013). Moreover, disease reduction has been correlated with sustained microbial stability in formulations after storage (Costa et al 2002;Xue et al 2014).…”