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.

This chapter discusses the global impact of phytonematodes on crop production and presents a recent assessment of crop losses caused by these tiny creatures. The habitat, taxonomy, biology, parasitism, sampling, spatial distribution, contribution in the soil food web and management of plant parasitic nematodes are described. Progress in molecular and biochemical studies on these nematodes is highlighted. The economically important plant parasitic nematodes worldwide, as well as the economic thresholds for damage by these nematodes, are also described. Future prospects are mentioned.

Four citrus orchards in Egypt were used in 2011 to study spread and losses of Tylenchulus semipenetrans based on a preliminary report of their infection in 2008. Soil and root samples indicated aggregated distribution and increase of nematode populations. The relationship between nematode number and lemon yield was described. When yield data of the mature groves were combined, we could construct other equations. The gain thresholds were 6.083 and 4.014 metric tons of lemon feddan−1 (= 4200 m−2) and the economic thresholds were 1810 and 141 second-stage juveniles (150 cm3 soil)−1 for cadusafos and oxamyl, respectively, based on the combined costs of nematode sampling and control to provide an actual estimate of a budget conscious choice. The use of healthy material is compulsory for tackling this problem in Egypt as a case in point. It entails setting up a citrus certification programme. Other phytosanitary measures to protect citriculture interests in Egypt are discussed.

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.

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.