Plant-parasitic nematodes (PPNs) pose a serious threat to quantitative and qualitative production of many economic crops worldwide. An average worldwide crop loss of 12.6% (equaled $215.77 billion) annually has been estimated due to these nematodes for only the top 20 life-sustaining crops. Due to the growing dissatisfaction with hazards of chemical nematicides, interest in microbial control of PPNs is increasing and biological nematicides are becoming an important component of environmentally friendly management systems. Fungal and bacterial nematicides rank high among other biocontrol agents. In order to maximize their benefits, such bio-nematicides can be included in integrated nematode management (INM) programs, and ways that make them complimentary or superior to chemical nematode management methods were highlighted. This is especially important where bio-nematicides can act synergistically or additively with other agricultural inputs in integrated pest management programs. Consolidated use of bio-nematicides and other pesticides should be practiced on a wider basis. This is especially important, since there are many bio-nematicides which are or are likely to become widely available soon. Identification of research priorities for harnessing fungal and bacterial nematicides in sustainable agriculture as well as understanding of their ecology, biology, mode of action, and interaction with other agricultural inputs is still needed. Therefore, accessible fungal and bacterial nematicides with their comprehensive references and relevant information, i.e., the active ingredient, product name, type of formulation, producer, targeted nematode species and crop, and country of origin, are summarized herein.

Plant-parasitic nematodes (PPNs) infect and cause substantial yield losses of many foods, feed, and fiber crops. Increasing concern over chemical nematicides has increased interest in safe alternative methods to minimize these losses. This review focuses on the use and potential of current methods such as biologicals, botanicals, non-host crops, and related rotations, as well as modern techniques against PPNs in sustainable agroecosystems. To evaluate their potential for control, this review offers overviews of their interactions with other biotic and abiotic factors from the standpoint of PPN management. The positive or negative roles of specific production practices are assessed in the context of integrated pest management. Examples are given to reinforce PPN control and increase crop yields via dual-purpose, sequential, and co-application of agricultural inputs. The involved PPN control mechanisms were reviewed with suggestions to optimize their gains. Using the biologicals would preferably be backed by agricultural conservation practices to face issues related to their reliability, inconsistency, and slow activity against PPNs. These practices may comprise offering supplementary resources, such as adequate organic matter, enhancing their habitat quality via specific soil amendments, and reducing or avoiding negative influences of pesticides. Soil microbiome and planted genotypes should be manipulated in specific nematode-suppressive soils to conserve native biologicals that serve to control PPNs. Culture-dependent techniques may be expanded to use promising microbial groups of the suppressive soils to recycle in their host populations. Other modern techniques for PPN control are discussed to maximize their efficient use.

Due to the increased economic and social benefits of the strawberry crop yield in Egypt, more attention has been paid to control its pests and diseases. Leaf blight, caused by the fungus Phomopsis obscurans, is one of the important diseases of strawberry plants. Therefore, effect of silicon and potassium, sodium and calcium silicates, and a fungicide on Phomopsis leaf blight of strawberry under laboratory and field conditions was examined. Four concentrations, i.e., 0, 2, 4, and 6 g/l of silicon as well as potassium, sodium and calcium silicates could significantly reduce the linear growth of tested fungus in the laboratory test where complete inhibition of linear growth was obtained with 6 g/l. The other concentrations showed less but favorable effects. The highest reduction of disease severity was obtained with potassium silicate and calcium silicate separately applied as soil treatment combined with foliar spray which reduced the disease incidence by 83.3 and 86.7%, respectively. Other treatments showed significant (P ≤ 0.05) but less effect. The highest yield increase was obtained with potassium silicate and calcium silicate applied as soil treatment combined with foliar spray which increased fruit yield by 60 and 53.8%, respectively. All tested treatments increased (P ≤ 0.05) the activities of the peroxidase, polyphenol oxidase, and chitinase enzymes. All tested concentrations of silicon salts have suppressed the fungal growth and disease spread but with different degrees. The more the concentration, the better it suppresses the fungal growth and consequent effect on damaging strawberry plants. Potassium silicate and calcium silicate separately applied as soil treatment combined with foliar spray were the best in reducing the disease incidence and increasing crop yield. Potential implications of silicate salts on enhancing activities of the tested enzymes reflected their role in protection against such a plant disease.

Biological control agents (BCAs) are increasingly used against various plant-parasitic nematode (PPN) pests and offer a favorable alternative to hazardous chemical nematicides. Yet, their lack of efficacy, inconsistent field performance, and/or unfavorable economic factors have generally relegated them to a relatively small sector of pesticide market. Efficacy and biocontrol success can be boosted via holistic grasping of soil biological and ecological factors. Therefore, such factors were highlighted to give better directions for their use. Main points discussed currently are considered to affect the transmission success of these BCAs so that their use must be a way forward in crop protection/pest management. These included improved sampling, grasping BCAs interactions with soil biota and ecology, cost-effective use of BCAs, genetic manipulation for better PPN control, grower acceptance and awareness-raising of BCA techniques, and commercial application.

Developing control measures of plant-parasitic nematodes (PPNs) rank high as they cause big crop losses globally. The growing awareness of numerous unsafe chemical nematicides and the defects found in their alternatives are calling for rational molecular control of the nematodes. This control focuses on using genetically based plant resistance and exploiting molecular mechanisms underlying plant–nematode interactions. Rapid and significant advances in molecular techniques such as high-quality genome sequencing, interfering RNA (RNAi) and gene editing can offer a better grasp of these interactions. Efficient tools and resources emanating from such interactions are highlighted herein while issues in using them are summarized. Their revision clearly indicates the dire need to further upgrade knowledge about the mechanisms involved in host-specific susceptibility/resistance mediated by PPN effectors, resistance genes, or quantitative trait loci to boost their effective and sustainable use in economically important plant species. Therefore, it is suggested herein to employ the impacts of these techniques on a case-by-case basis. This will allow us to track and optimize PPN control according to the actual variables. It would enable us to precisely fix the factors governing the gene functions and expressions and combine them with other PPN control tactics into integrated management.