One of the most favored trends in modern agriculture is biological control. However, many reports show that survival of biocontrol bacteria is poor in host plants. Providing biocontrol agents with protection by encapsulation within external coatings has therefore become a popular idea. Various techniques, including extrusion, spray drying, and emulsion, have been introduced for encapsulation of biocontrol bacteria. One commonly used biopolymer for this type of microencapsulation is alginate, a biopolymer extracted from seaweed. Recent progress has resulted in the production of alginate-based microcapsules that meet key bacterial encapsulation requirements, including biocompatibility, biodegradability, and support of long-term survival and function. However, more studies are needed regarding the effect of encapsulation on protective bacteria and their targeted release in organic crop production systems. Most importantly, the efficacy of alginate use for the encapsulation of biocontrol bacteria in pest and disease management requires further verification. Achieving a new formulation based on biodegradable polymers can have significant effects on increasing the quantity and quality of agricultural products.

Arbuscular mycorrhizal fungi (AMF) are one of the environment-friendly organisms that increase soil fertility. Hence, AMF affect the herbivorous insect community by indirectly modifying host plant nutrient uptake, growth and defense, also known as priming. Here in the current study, we investigated under greenhouse conditions the effect of inoculation of tomato seedlings with four species of AMF (Funneliformis mosseae, Rhizophagus intraradices, Rhizophagus irregularisandGlomus iranicus) on tomato plant growth parameters, plant defense enzymes, total phenol content, and the life table parameters of whiteflies,Bemisia tabaci(Gennadius) (Hemiptera: Aleyrodidae), that are important phloem-feeding pest insects. The results indicated that the growth parameters of tomato plants (including plant height, stem diameter, number of leaves, root volume, leaf surface area and weight root and aerial organs) were greater and larger in the mycorrhizal plants compared to the non-mycorrhizal plants. Twenty days after exposing the plant toB. tabacithe largest amounts of defense enzymes comprising of peroxidase, phenylalanine ammonia lyase, polyphenol oxidase and total phenol contents were measured in the mycorrhizal plants compared to non-mycorrhizal plants. Furthermore, the life table parameters of the whitefly pest insects (net reproduction rate, R₀; intrinsic rate of natural increase in insect population, r; finite rate of population increase, λ; and the mean generation time, T) were decreased in the mycorrhizal plants compared to the non-mycorrhizal plants. Altogether, we believe that our plant-based results obtained here under greenhouse conditions are indications that AMF colonization enhanced tomato resistance toB. tabaciby improving plant growth parameters and increasing defense enzymes.