Trap Crop Research Articles

Evaluation of trap crop, Solanum sisymbriifolium and antagonistic crops against potato cyst nematodes, Globodera spp.

The potato cyst nematodes are the most wilful and difficult to manage pests of potato crop. Due to the regulatory considerations and potential risk involved in environmental and health hazards, the options for controlling this nematode are becoming increasingly limited. Among the available management options, trap and antagonistic crops offer viable alternative for controlling PCN species. Therefore the present experiments were conducted to determine the effect of locally available nematode trap crop, Solanum sisymbriifolium and antagonistic crops against potato cyst nematodes. Initially, S. sisymbriifolium was evaluated for its trap crop potential against PCN and the results showed that S. sisymbriifolium acts as a resistant crop for both the species of PCN, as no females were observed on the roots of the trap crop up to the end of the crop season. In addition to this, in the subsequent season negligible populations of PCN females with improved plant growth parameters were observed in susceptible potato cv. Kufri Jyoti. In another experiment, its efficiency was compared with antagonistic crop species viz., Tagetes patula (marigold), Allium sativum (garlic) and Brassica juncea (mustard) on the population decline of PCN. From the study, it was observed that minimum populations of both the species of PCN (0.6 and 33.4 female's plant−1 respectively) were supported in two succeeding seasons of susceptible potato cultivar where S. sisymbriifolium was grown in the preceding season which was followed by marigold, garlic and mustard-based sequences. Therefore, S. sisymbriifolium can be used as a potential trap crop for the management of PCN; however, future studies on its suitability in field conditions are required for its effective utilization under field condition for the management of this nematode.

Control of Meloidogyne graminicola a Root-Knot Nematode Using Rice Plants as Trap Crops: Preliminary Results

Meloidogyne graminicola is one of the most harmful organisms in rice cultivation throughout the world. This pest was detected for the first time in mainland Europe (Northern Italy) in 2016 and was subsequently added to the EPPO Alert List. To date, few methods are available for the control of M. graminicola and new solutions are required. In 2019, field trials using rice plants as trap crops were performed in a Lombardy region rice field where five plots for three different management approaches were staked out: (i) Uncultivated; (ii) Treated: three separate cycles of rice production where plants were sown and destroyed each time at the second leaf stage; (iii) Control: rice was sown and left to grow until the end of the three cycles in treated plots. The results showed that in the treated plots, the nematode density and the root gall index were lower than for the other two management approaches. Moreover, the plant population density and rice plant growth were higher than the uncultivated and control plots. In conclusion, the use of the trap crop technique for the control of M. graminicola gave good results and thus it could be a new phytosanitary measure to control this pest in rice crop areas.

Arthropod Demography, Distribution, and Dispersion in a Novel Trap-Cropped Cotton Agroecosystem.

Vernonia [Vernonia galamensis (Cass.) Less.] (Asterales: Asteraceae) was examined as a potential trap crop for the cotton (Gossypium hirsutum L., Malvales: Malvaceae) arthropod complex. Four rows of vernonia were embedded within a 96-row cotton field. The abundance of true bug pests, true bug predators, and spiders were determined by whole-plant and sweep net sampling procedures during the early, middle, and late phases of the cotton-growing season. The census data showed that the arthropods had a strong preference for the vernonia trap crop throughout the cotton-growing season. The movement of the arthropods from the trap crop into cotton was also measured using the protein immunomarking technique as a mark-capture procedure. The arthropods inhabiting the vernonia trap crop were marked directly in the field with a broadcast spray application of egg albumin (protein) during each phase of the study. In turn, the captured specimens were examined for the presence of the mark by an egg albumin-specific enzyme-linked immunosorbent assay. Very few marked specimens were captured beyond the vernonia trap crop 1, 3, and 6 d after each marking event. The arthropods' strong attraction and fidelity to vernonia indicate that it could serve as a trap crop for cotton pests and a refuge for natural enemies.

Evaluation of certain bio-intensive integrated pest management (BIPM) modules against Spodoptera litura (Fabricius) in blackgram

Field experiments were conducted to evaluate the efficacy of a bio-intensive IPM modules including organic nutrients and botanicals against Spodoptera litura on black gram. The results revealed that combined application of neem cake, installation of pheromone traps, and growing castor as trap crop was found to be effective in reducing the larval population of S. litura (module-3) as compared to untreated check. The highest seed yield of 874 kg/ha and 898 kg/ha was recorded in this module (M-III) with BCR of 1:2.81 and 1:2.70 during kharif 2017 and rabi 2018, respectively followed by module-4.

Fall Armyworm, Spodoptera frugiperda (J.E. Smith) Management Strategies: A Synopsis

Fall armyworm (Spodoptera frugiperda) is a polyphagous pest with a host range, native to North and South America. This pest was formally reported for the first in January 2016 in Africa and in May 2018 in India. On 9 May 2019, this pest was first noticed in Nawalpur Nepal. 20-35% losses have been reported in maize crops. Since the outbreak of this pest from Africa, entomologists are working for their strategic management. This review aims to compile the fall armyworm (FAW) management works carried in the world and discuss their relevancy in Nepalese context. Of the various practices, chemical pesticides are one of the most commonly used tools followed by habitat management and other cultural practices. Insect pheromones are used for pest monitoring, and thereby to improve pest management decisions. Trap cropping, cover cropping, intercropping, maintaining floral diversity are some examples of habitat pest manipulation. Push-pull strategy uses Napier crop as a ‘Pull’ component and Desmodium crop as a ‘Push’ crop. These agro-ecological strategies change the behavior of FAW and able to trap or manage them in a certain area or certain crop, where pest can be managed manually or using other non-insecticidal strategies. This review work will be useful for the academicians, extension workers and plant protectionist to design a sustainable FAW management protocol.

Use of safflower as a trap crop for managing the mirid bug, Lygus pratensis Linnaeus (Hemiptera: Miridae), in cotton fields.

Cotton has been increasingly harmed by the mirid bug (Lygus pratensis Linnaeus) in Xinjiang Uyghur Autonomous Region, China. Using trap plants within or around the border of the cotton may be a beneficial management strategy for this pest of cotton. The potential of safflower (Carthamus tinctorius Linn) as a trap plant for managing L. pratensis was evaluated in laboratory and field experiments. Y-tube olfactometer assays demonstrated that L. pratensis was highly attracted to volatiles derived from safflower. Field experiments showed that safflower plots hosted more L. pratensis (adults and nymphs) than cotton plots. Early-sown safflower had more L. pratensis than mid-sown or late-sown safflower, and was more conducive to the settlement and reproduction of L. pratensis. The density of L. pratensis on safflower trap crops in three sowing patterns was significantly higher than on adjacent cotton. The pattern of intercropping safflower trap crops was more effective at reducing densities of L. pratensis on cotton than placing safflower as 'spot' trap crops or peripheral trap crops. However, this result also may be related to the overall area of the safflower trap crops. With regular chemical control of L. pratensis on safflower trap crops, the number of cotton bolls was increased by 10.04%, whereas the rate of boll damage was reduced by 33.44%, compared to cotton without safflower trap crops and insecticide sprays. Safflower shows promise as an effective trap crop for L. pratensis, and may contribute to controlling L. pratensis in cotton. © 2020 Society of Chemical Industry.

Performance of various trap crops in the management of Thrips tabaci L. in onion crop

Performance of various trap crops in the management of Thrips tabaci L. in onion crop

Which Pitfall Traps and Sampling Effort to Choose to Evaluate Cropping System Effects on Spider and Carabid Assemblages?

In arable agroecosystems, arthropod communities often have a reduced abundance and diversity, which represents a challenge for sampling techniques needed to detect small differences among these simplified communities. We evaluated the suitability of pitfall traps for comparing the effects of cropping systems on arthropod communities. In a field experiment, we compared the effects of two pitfall trap diameters, the type of preserving fluid and the sampling effort on three metrics (activity density, taxonomic richness, and community weighted mean [CWM] of body size) for carabids and spiders. Trap size affected the observed composition of communities, with large traps yielding a higher proportion of spiders, and a higher richness and CWM body size for both taxa. The type of preserving fluid had a weaker effect. Simulations with various sampling efforts showed that only very different communities could be distinguished with less than 10 traps per field or less than 30 field replicates. Fewer traps were required to find differences between cropping systems for body size than for other metrics. Carabid activity density and body size, and spider genus richness, were the variables better distinguishing between cropping systems with the smallest sampling effort. A high sampling effort was required for comparing activity density and richness across cropping systems. Selection of the most appropriate trap design, metrics, and crops are the main factors for optimizing the trade-off between sampling effort and the ability to detect arthropod community responses to habitat management.

Sparrow Preferences for Winter Cover Crops in California's Central Coast

Agriculture in many regions of the world has reduced bird habitat and abundance, and altered avian community structure. A study was conducted on an organic research farm over two winters (Oct to Mar) in an intensive agricultural region of Salinas Valley, CA to determine how cover crop variety and planting density influenced birds. Cover crops were rye (Secale cereale), a mixture of rye and legumes (Vicia spp., Pisum sativum), and a mustard mixture (Brassica juncea, Sinapis alba). White-crowned Sparrows (Zonotrichia leucophyrs), Savannah Sparrows (Passerculus sandwichensis) and Song Sparrows (Melospiza melodia) were observed both years in the study field. Bird droppings in cover crops were quantified and dissected to determine dietary preferences, and sparrow movement when flushed was determined. Dropping number and weight per m2 were at least 10 times greater in mustard than in rye and in the legume-rye mixture. Droppings were dominated by leaf tissue in mustard versus arthropod tissue in rye and legume-rye. Within cover crop variety, plant density did not have a clear or consistent effect on sparrows. Sparrows flushed from cover crops usually settled in mustard. The White-crowned Sparrow fed on mustard leaves and apparently on weed foliage under mustard. The arthropod-dominated droppings in rye and legume-rye cover crops were consistent with the food preferences of Song and Savannah Sparrows. The White-crowned Sparrow’s clear preference for mustard cover crops is likely due in part to their high dietary needs for sulfur-rich amino acids during the prenuptual molt. This paper provides novel information to help farmers and others understand the cover crop preferences of sparrows, and ways that farmers might use mustard cover crops as trap crops to reduce White-crowned Sparrow feeding damage on winter and spring vegetable crops. It also provides evidence of ecosystems services that these sparrows provide by feeding on weed tissue in winter cover crops.

A chemical basis for different oviposition rates of Helicoverpa assulta across two Nicotiana species

The tobacco Nicotiana rustica is widely used as a trap crop in the fields of Nicotiana tabacum in China, by attracting oviposition of Helicoverpa assulta females, thus preventing damage to N. tabacum. The mechanism underlying the differential oviposition rates of H. assulta across these two tobacco species, however, is largely unknown. We investigated the mechanism of host plant acceptance of H. assulta with respect to these two tobaccos by using a two-choice behavioral bioassay and GC–MS. Our results indicate that both the leaves and inflorescences of N. rustica attracted significantly more eggs than the corresponding parts of N. tabacum. Extracts of leaves and inflorescences of N. rustica with two different solvents elicited similar oviposition patterns to the corresponding parts of the plants. Chemical analysis by GC–MS revealed that the volatiles of N. rustica contain larger amounts of nicotine than those of N. tabacum at the flowering stage. In addition, γ-terpinolene and β-elemene are found only in extracts of N. rustica. A two-choice bioassay on the individual compounds showed that γ-terpinolene, which is specific to the vegetative stage of N. rustica, and nicotine attracted oviposition by H. assulta. The volatile β-elemene, which is present only in N. rustica, was also attractive. We conclude that the larger amount of nicotine, and the species-specific γ-terpinolene and β-elemene may mediate the different oviposition rates of H. assulta females across N. rustica and N. tabacum.

Influence of Trap Crops on Tomato and Squash Insect Pests

Influence of Trap Crops on Tomato and Squash Insect Pests

A new pest management strategy: transforming a non-host plant into a dead-end trap crop for the diamondback moth Plutella xylostella L.

The use of trap crops can reduce the egg production of female Plutella xylostella in cruciferous vegetables and is an effective method for controlling this pest. To date, most of the trap plants that have been studied are cruciferous plants containing high concentrations of glucosinolates, which are more attractive to P. xylostella female adults. However, the application of these trap plants also has some limitations. Studies have shown that aqueous extracts of cruciferous plants can attract P. xylostella to lay eggs. In this study, we utilized the extract of Chinese kale to treat a non-host plant, the faba bean, and evaluated the possibility of using it as a dead-end trap plant for P. xylostella control. Plutella xylostella females laid significantly more eggs on faba beans that had been sprayed with the extract of Chinese kale rather than on Chinese kale itself. The first instar larvae of P. xylostella failed to survive on faba beans. Notably, the faba beans with the Chinese kale extract had the strongest attraction effect on P. xylostella females when placed 3 m away from the Chinese kale. Moreover, this attraction effect of faba beans on P. xylostella for oviposition lasted for up to 15 days. Faba bean plants sprayed with the aqueous extract of Chinese kale represent a potential dead-end trap plant for P. xylostella adults and their oviposition while being invariably deadly for their offspring. The present study provides a new proof of concept of using a non-cruciferous trap plant for P. xylostella management.

Integrated management protocol for New Zealand endemic wheat bug (Nysius huttoni) in forage brassicas

Wheat bug, Nysius huttoni, is considered as an economic pest of forage Brassicas and many other cultivated crops, such as wheat, kale, and vegetables in New Zealand. Insecticides- as seed coatings and sprays are frequently used to manage this pest, but a high proportion of these insecticidal compounds enter the soil and leads to pesticide resistance, and they may impact beneficial arthropods and soil microorganisms, creating an adverse effect on ecosystem services (ES). In this paper, we discuss a technology, that we have developed to trap , for example, wheat bug away from kale seedlings, and integrating these in less susceptible kale cultivars that can potentially reduce over-reliance on orthodox pesticides on brassicas. Laboratory studies were conducted to screen the suitable trap crop among nine other plants (alyssum, wheat, phacelia, buckwheat, coriander, white clover, alfalfa, and kale) mainly by considering growth stages (vegetative and flowering), and select less susceptible kale cultivars among six other (Kestrel, Gruner, Sovereign, Regal, Corka and Colear). Alyssum (Lobularia maritima) and wheat (Triticum aestivum) were the most favoured potential trap plants for the wheat bug in a laboraotry study. Flowering stage of alyssum is the most susceptible growth stage by the bug damage. Kestrel and Coleor are the most popular kale cultivars used as forage brassicas in New Zealand, but they are the most susceptible to the wheat bug. Corka and Regal were the least susceptible cultivars. The integration of trap cropping technology by using alyssum as the trap crop, preferably depolying flowering stage, along with sowing less susceptible kale cultivars such as Corka and Regal in main fields have been suggested to protect brassica seedlings from bug damage.

Hatching of Globodera pallida Induced by Root Exudates Is Not Influenced by Soil Microbiota Composition.

Plant-parasitic nematodes are among the most harmful pests of cultivated crops causing important economic losses. The ban of chemical nematicides requires the development of alternative agroecological approaches to protect crops against nematodes. For cyst nematodes, egg hatching is stimulated by host plant root exudates. Inducing “suicide hatching” of nematode second-stage juveniles (J2), using root exudates in the absence of the host plant, may constitute an effective and innovative biocontrol method to control cyst nematodes. However, before considering the development of this approach, understanding the effect of soil biotic component on cyst nematode hatching by root exudates is a major issue. The effectiveness of this approach could be modulated by other soil organisms consuming root exudates for growth as soil microbiota, and this must be evaluated. To do that, four different native agricultural soils were selected based on their physicochemical properties and their microbiota composition were characterized by rDNA metabarcoding. To disentangle the effect of microbiota from that of soil on hatching, four recolonized artificial soils were obtained by inoculating a common sterile soil matrix with the microbiota proceeding from each agricultural soil. Each soil was then inoculated with cysts of the potato cyst nematode, Globodera pallida, and low or high doses of potato root exudates (PREs) were applied. After 40 days, viable J2 remaining in cysts were counted to determine the efficiency of root exudates to stimulate hatching in different soils. Results showed that (i) when physicochemical and microbiota compositions varied among native soils, the hatching rates remained very high albeit small differences were measured and no dose effect was detected and (ii) when only microbiota composition varied among recolonized soils, the hatching rates were also high at the highest dose of PREs, but a strong dose effect was highlighted. This study shows that abiotic and biotic factors may not compromise the development of methods based on suicide hatching of cyst nematodes, using root exudates, molecules inducing J2 hatch, or trap crops.

Field evaluation of sunflower as a potential trap crop of Lygus pratensis in cotton fields.

The mirid bug Lygus pratensis is an important pest of cotton, and is primarily managed through insecticide application. In this study, conducted in Xinjiang (China), we assessed the relative attractiveness of sunflower (Helianthus annuus) to L. pratensis adults in local cotton plots from 2015-2016 and quantified the associated contribution of inter-planted sunflower strips to suppress field-level L. pratensis populations from 2016-2017. Field-plot trials showed that among six combinations of two sunflower varieties (XKZ6 and SH363) and three planting dates (early-, middle- and late-planted), adult abundance of L. pratensis was highest on early-planted XKZ6 and attained 3.7-5.8 times higher levels than in neighboring cotton plots. In commercial cotton fields, the combined deployment of sunflower strips at field edges and the periodic application of insecticides directed to those strips was found to (1) reduce the mean abundance of L. pratensis population on cotton by 41.9-44.0%, (2) lower the rate of cotton leaf damage by 27.3-30.6% and boll damage by 44.8-46.0%, and (3) increase the number of mature bolls by 7.5%-8.0%. Our work emphasizes how sunflower can be an effective trap crop for L. pratensis and that the establishment of sunflower strips could contribute to its effective and environmentally-sound management in cotton crops.

Attack and aggregation of a major squash pest: Parsing the role of plant chemistry and beetle pheromones across spatial scales

Abstract Successful management of insect crop pests requires an understanding of the cues and spatial scales at which they function to affect rates of attack of preferred and non‐preferred host plants. A long‐standing conceptual framework in insect–plant ecology posits that there is hierarchical structure spanning host location, acceptance and attack that could be exploited for integrated pest management. We investigated how plant‐ and insect‐derived chemical cues affect successive decisions of host choice in aggregating insects, and tested predictions in the Cucurbita pepo–Acalymma vittatum system. Acalymma vittatum is an aggregating specialist beetle pest that strongly prefers zucchini (C. p. pepo) to summer squash (C. p. ovifera), two independent domesticates of C. pepo. We hypothesized that subspecies‐specific plant traits, especially volatile cues, interact with the male‐produced aggregation pheromone to amplify beetle preference for C. p. pepo. Differential beetle attack of C. pepo subspecies in the field is not determined by plant traits that affect host finding or differential aggregation due to pheromones: across two years, beetles had strong density‐dependent attraction to both subspecies when male beetles were feeding, and no interactions between plant volatiles and the male‐produced pheromone were detected. In the absence of male pheromone emission, beetles were equally unattracted to plants with or without beetle feeding. In contrast, plant traits that mediate insect acceptance appear to underlie differences in preference. At a local scale, beetles did not accept and emigrated from C. p. ovifera compared to C. p. pepo. Distinct volatile emissions were observed between subspecies, but further work is needed to identify if these volatiles promote emigration. Synthesis and applications. By dissecting pest preference during successive host choice decisions, we isolated a trait with implications for pest management. Beetles on cucurbits can be managed by employing cultivars with differential susceptibility (e.g. trap cropping), and the mechanistic knowledge presented here informs best practices and limitations for on‐farm applications. More broadly, pest management in diversified cropping systems can be enhanced through understanding how plant preference gradients affect herbivore movement and behaviour, and plant breeders can target traits to reduce herbivory in such systems.

Witchweed’s Suicidal Germination: Can Slenderleaf Help?

The parasitic plant Striga hermonthica (Delile) Benth. is stimulated to germinate by biomolecules (strigolactones) produced in the roots of host and some non-host plants. Non-hosts induce Striga’s suicidal germination and are therefore used as trap crops. Among trap crops, the Slenderleaf legume in the genus Crotalaria (Crotalaria brevidens (L.) Benth.) and (Crotalaria orchroleuca (G.) Don.) has been popularized in African smallholder farms. However, the Striga germination efficiency of these locally grown Crotalaria varieties (landraces) is unknown. Also unclear is Crotolaria’s extent to inhibiting Striga growth, post germination. Extensive parasite penetration can expose the trap crop to secondary infections and possible phytotoxicity from Striga. We used in vitro germination assays to determine the Striga germination efficiency of 29 Crotalaria landraces. Furthermore, we determined Crotalaria’s ability to inhibit Striga attachment and growth using histological analysis. We found that: i) Crotalaria stimulated germination of Striga seeds at frequencies ranging between 15.5% and 54.5% compared to 74.2% stimulation by the synthetic strigolactone (GR24) used a positive control; ii) Crotalaria blocked Striga entry at multiple levels and did not allow growth beyond the pericycle, effectively blocking vascular connection with the non-host. Hence, Crotalaria is suitable as a trap crop in integrated Striga management.

Plant Selection for the Establishment of Push-Pull Strategies for Zea mays-Spodoptera frugiperda Pathosystem in Morelos, Mexico.

Regulations imposed on the use of chemical insecticides call for the development of environmental-friendly pest management strategies. One of the most effective strategies is the push–pull system, which takes advantage of the behavioral response of the insect to the integration of repellent stimuli; it expels the pest out of the main crop (push), while attracting stimuli (attractants) pull the pest to an alternative crop or trap (pull). The objective of this study was to design a push–pull system to control Spodoptera frugiperda in maize crops (Zea mays) in Morelos, Mexico. Data on reproductive potential, larvae development, food consumption and olfactometry were used to obtain a Trap Plant Selection Index (TRAPS) based on Principal Component Analysis. This TRAPS was used to select the most suitable plants. The degree of repellency of potential plants to be used as the trap crop was studied with four-way olfactometers. S. frugiperda females oviposited more eggs on Brachiaria hybrid cv. Mulato II, Panicum maximum cv. Mombasa and Panicum maximum cv. Tanzania than on Z. mays, regardless of the fact that these plants delayed the development of their offspring. Dysphania ambrosioides, Tagetes erecta and Crotalaria juncea were less attractive to S. frugiperda females. Therefore, the former plants could be used as crop traps, and the latter as intercropped repellent plants in a push–pull system.

Kairomone-assisted trap cropping for protecting spring oilseed rape (Brassica napus) from pollen beetles (Coleoptera: Nitidulidae).

Pollen beetles are key pests in oilseed rape (OSR) production. These beetles use visual and olfactory cues to locate their host plants at specific phenological stages, hence trap cropping may represent an alternative pest control strategy. In this study, a trap crop strategy for spring OSR was developed. To elaborate such a trap cropping system, a pest control measure that eradicates the attracted beetles in the trap crop before they migrate further into the main crop was included in the final trap cropping strategy. Testing yellow-flowering turnip rape and one yellow- and two cream-coloured flowering OSR cultivars as potential crops in different trap cropping strategies, we found that pollen beetles clearly preferred turnip rape over the cream-coloured and yellow OSR cultivars, and preferred the yellow OSR cultivar over the two cream-coloured cultivars. This behaviour was related to the plant growth stage and associated volatile and colour signals of the tested cultivars. Using turnip rape as a trap crop and testing kairomone- or insecticide-assisted trap cropping as the pest control strategy was as effective as compared with whole fields treated with a standard pesticide. Combining a turnip rape cultivar as trap crop with kairomone traps placed in the trap crop as a killing agent may enable renunciation of pesticides in spring OSR production. © 2020 Society of Chemical Industry.

Alternative hosts of Spongospora subterranea f. sp. subterranea in southern Africa

Spongospora subterranea f. sp. subterranea (Sss) is an obligate parasite that can only multiply within the living tissues of a host plant. Greenhouse experiments were carried out to determine the host status of Sss in some crops and weeds commonly found in southern African fields. These experiments used both qPCR and light microscope examination to study the development of Sss in the roots of weeds and crops grown in inoculated Merz solution. Zoosporangia and sporosori were observed microscopically in weed species Acanthospermum hispidum, Ageratum conyzoides, Bidens pilosa, Cleome monophylla, Datura stramonium, Euphorbia heterophylla, Oxalis latifolia, Physalis angulata, Setaria pumila and Tagetes minuta, whilst Ipomea plebia, Setaria verticillata and Galinsoga parviflora were non-hosts of Sss. Root galls were only observed on D. stramonium roots. The crops Allium cepa, Solanum lycopersicum, Zea mays, Avena sativa and Triticum aestivum were both zoosporangial and sporosorial hosts, whilst Phaseolus vulgaris and Brassica juncea were sporosorial hosts only. This study has added three new families to the hosts of Sss, namely Oxalidaceae, Euphorbiaceae and Cappardaceae. Two zoosporangial hosts were identified, namely Avena strigosa and Glycine max. These crops would be ideal to be included as trap crops in rotations with potatoes. The highest quantity of Sss DNA in weed species was recorded in the roots of P. angulata, N. physalodes and A. conyzoides, whilst in cultivated crops the highest quantity of Sss DNA was recorded in Brassica juncea followed by Avena strigosa. The study has shown the importance of weeds and some crops used in rotation with potatoes as alternative hosts of Sss and their potential to increase Sss inoculum level in the soil.