Allium Ampeloprasum Research Articles

Comparative phytochemical profile of the elephant garlic (Allium ampeloprasum var. holmense) and the common garlic (Allium sativum) from the Val di Chiana area (Tuscany, Italy) before and after in vitro gastrointestinal digestion

This study is aimed to comparatively investigate the phytochemical profiles, focusing on the nutritional and phytochemical properties of common garlic (Allium sativum L.; CG) and elephant garlic (EG) (Allium ampeloprasum var. holmense) collected from the Val di Chiana area (Tuscany, Italy). The results showed a lower amount of fibers, demonstrating a higher digestibility of the bulb, and sulfur-containing compounds in EG rather than in CG. Untargeted metabolomic profiling followed by supervised and unsupervised statistics allowed understanding the differences in phytochemical composition among the two bulbs, both as raw bulbs, processed following the in vitro gastrointestinal digestion process. Typical sulfur-containing compounds, such as alliin and N-gamma-glutamyl-S-allyl cysteine, could notably be detected in lower amounts in EG. EG maintains a distinct phytochemical signature during in vitro gastrointestinal digestion. Our findings support the distinct sensorial attributes of the bulbs.

Variation in Amino Acids Composition through Pre column Derivatisation using Phenylisothiocyanate by HPLC in Some Economically Important Less Explored Wild Allium Species of Western Himalayas

Less explored Allium species are being used as green vegetables and as a condiment by the local inhabitant of high-altitude areas of Uttarakhand. In the present study, four economically important less explored wild Allium species viz. A. auriculatum, A. ampeloprasum, A. ascalonicum and A. rubellum have screened for their amino acid contents by High-performance liquid chromatography. The hydrochloric acid hydrolysate of these four species, the Allium amino acids were derivatised with phenylisothiocyanate resulting phenylthiocarbamyl derivatives and separated on a reverse-phase column by gradient elution with aqueous buffer and acetonitrile-water (60:40 v/v) and detected in UV region at 254 nm. The Pico-tag (3.9 × 300 mm) C18 column equilibrated with the solvents. The elution of all amino acid derivatives was achieved in 12 min using gradient elution by increasing concentration of aqueous buffer and acetonitrile-water. Total seventeen amino acids were present in these Allium species. The ratio of essential amino acids to total amino acids found 1:2.14 in Allium auriculatum, 1:2.35 in Allium ampeloprasum, 1:1.38 in A. ascalonicum and 1:3.44 in Allium rubellum. These less explored Allium species contained substantial amount of essential and non-essential amino acids. Among these Allium species, Allium auriculatum and Allium rubellum found most promising as far as essential and non-essential amino acids composition concerned.

The anticholesterol oxidation effects of garlic (Allium sativum L.) and leek (Allium ampeloprasum L.) in frozen fish burgers submitted to grilling.

This study determined the total phenolic content and antioxidant capacity of garlic (Allium sativum L.) and leek (Allium ampeloprasum L.), as well as evaluated their anticholesterol oxidation potential in fish burgers. The total phenolic contents were 1.1±0.1mg GAE/g FW to garlic and 1.3±0.4mg GAE/g FW for leek. Leek extract showed antioxidant activity index (1.3±0.01) in DPPH and β-carotene/linoleic acid assay (66.5±1.6%); however, in ORAC assay, no statistic differences were observed (P>0.05). Besides that, bioactive compounds of garlic and leek extracts were identified by ultra-high performance liquid chromatography-electrospray by ionization-mass spectrometry (UHPLC-ESI-MS). Fish burgers were prepared using different concentrations of leek and garlic and stored at -18 °C for 90 days. Thus, at days 0, 30, 60, and 90, the samples were grilled and analyzed as to their cholesterol and cholesterol oxidation products contents. Storage and grilling led to an increase in cholesterol oxidation products; however, addition of garlic and leek minimized cholesterol oxidation products formation. After 90 days, samples containing 3% leek + 0.5% garlic ware the most effective in inhibiting the cholesterol oxides formation during storage and showed the lowest increase in cholesterol oxidation products content (21.16%). Thus, the findings of this research indicate the potential application of garlic and leek as natural inhibitors of cholesterol oxidation in food. PRACTICAL APPLICATION: Garlic and leek have a set of bioactive compounds with a wide antioxidant capacity when used in meat foods such as fish burgers. Garlic and leek used as natural antioxidants perform well in the shelf life of fish burgers and can be substitutes for synthetic antioxidants in this type of product. The presence of both vegetables reduced the formation of prejudicial products to human health generated during the shelf life of the food.

The interaction between Rhizoglomus irregulare and hyphae attached phosphate solubilizing bacteria increases plant biomass of Solanum lycopersicum

The synergistic interaction between arbuscular mycorrhizal fungi (AMF) and phosphate solubilizing bacteria (PSB) can enhance growth and phosphorous uptake in plants. Since PSBs are well known hyphal colonizers we sought to understand this physical interaction and exploit it in order to design strategies for the application of a combined microbial inoculum. Phosphate-solubilizing bacteria strongly attached to the hyphae of Rhizoglomus irregulare were isolated using a two compartment system (root and hyphal compartments), which were separated by a nylon mesh through which AMF hyphae could pass but not plant roots. Allium ampeloprasum (Leek) was used as the host plant inoculated with R. irregulare. A total of 128 bacteria were isolated, of which 12 showed stable phosphate solubilizing activity. Finally, three bacteria belonging to the genus Pseudomonas showed the potential for inorganic and organic phosphate mobilization along with other plant growth promoting traits. These PSBs were further evaluated for their functional characteristics and their interaction with AMF. The impact of single or co-inoculations of the selected bacteria and AMF on Solanum lycopersicum was tested and we found that plants inoculated with the combination of fungus and bacteria had significantly higher plant biomass compared to single inoculations, indicating synergistic activities of the bacterial-fungal consortium.

Natural Antioxidants, Health Effects and Bioactive Properties of Wild Allium Species.

There is an increasing interest from the pharmaceutical and food industry in natural antioxidant and bioactive compounds derived from plants as substitutes for synthetic compounds. The genus Allium is one of the largest genera, with more than 900 species, including important cultivated and wild species, having beneficial health effects. The present review aims to unravel the chemical composition of wild Allium species and their healthrelated effects, focusing on the main antioxidant compounds. For this purpose, a thorough study of the literature was carried out to compile reports related to health effects and the principal bioactive compounds. Considering the vast number of species, this review is divided into subsections where the most studied species are presented, namely Allium ampeloprasum, A. flavum, A. hookeri, A. jesdianum, A. neapolitanum, A. roseum, A. stipitatum, A. tricoccum, and A. ursinum, with an additional composite section for less studied species. The information presented in this review was obtained from worldwide accepted databases such as Scopus, ScienceDirect, PubMed, Google Scholar and Researchgate, using as keywords the respective names of the studied species (both common and Latin names) and the additional terms of"antioxidants" "health effects" and "bioactive properties". The genus Allium includes several wild species, many of which are commonly used in traditional and folklore medicine while others are lesser known or are of regional interest. These species can be used as sources of natural bioactive compounds with remarkable health benefits. Several studies have reported these effects and confirmed the mechanisms of action in several cases, although more research is needed in this field. Moreover, considering that most of the studies refer to the results obtained from species collected in the wild under uncontrolled conditions, further research is needed to elucidate the effects of growing conditions on bioactive compounds and to promote the exploitation of this invaluable genetic material.

Product Innovation, Acceptability and Cost Analysis of the White Variety of ‘Sibujing’ (Allium ampeloprasum) for Potential Beverage

Product Innovation, Acceptability and Cost Analysis of the White Variety of ‘Sibujing’ (Allium ampeloprasum) for Potential Beverage

Metabolic profiling of different wild and cultivated Allium species based on high-resolution mass spectrometry, high-performance liquid chromatography-photodiode array detector, and color analysis.

Many plants of the genus Allium are widely cultivated and consumed for their nutraceutical and health-enhancing bioactive components effective in many metabolic and infectious diseases. In particular, Allium sativum L. (garlic), the most economically important Allium species, is known to present volatile, comparatively polar sulfur-containing compounds responsible for both the typical garlic aroma and antimicrobial property. More recently, the (moderately) polar portion of garlic metabolome, rich of polyphenols and amino acids, is gaining increasing interest as a source of antioxidants and primary nutrients. In this study, we have explored the chemical diversity of eight different hydroalcoholic extracts obtained by microwave-assisted extraction of white and red crop A. sativum and wild Allium triquetrum, Allium roseum, and Allium ampeloprasum, all originating from the Mediterranean Basin. The aim is to appraise their potential dietetic and healing value through an in-depth chemical characterization and contribute to preserve and exploit natural resources. The multimethodological method applied here is based on an untargeted metabolic profiling by means of high-resolution electrospray ionization Fourier-transform ion cyclotron resonance (ESI FT-ICR) mass spectrometry. More than 850 by ESI(+) and 450 by ESI(-) putative metabolites have been annotated covering all main classes of primary and secondary metabolites, including amino acids, alkaloids, organic and fatty acids, nucleotides, vitamins, organosulfur compounds, and flavonoids. The pigment and polyphenol components have been separated and quantified by a targeted chromatographic high-performance liquid chromatography-photodiode array detector (HPLC-PDA) and CIEL*a*b* colorimetric assay, showing characteristic yellow and red components in each extract, related to a different milieu of anthocyanins and flavonoids as assigned by high-resolution mass spectrometry (MS).

Leek or Garlic? A Chemical Evaluation of Elephant Garlic Volatiles.

“Aglione della Valdichiana” is listed among the Traditional Agronomic and Edible Products of Italy, as it is a typical product of the Chiana Valley (Tuscany, Italy). It is also known as “elephant garlic”, due to the dimension of its cloves, and, other than in the Italian Mediterranean area, its presence is also reported in North Africa and Southwest Asia. The current botanical classification identifies it as a leek variety (Allium ampeloprasum L.), although its appearance, except for its larger dimensions, resembles that of garlic. In the present study, the spontaneous volatile emission of whole and cut cloves of “Aglione della Valdichiana” (elephant garlic), garlic, and leek has been profiled by headspace solid phase micro-extraction. The results have been subjected to statistical analyses (analysis of variance, hierarchical cluster, and principal component analysis) to assess whether the chemical profile confirmed the botanical proximity of elephant garlic and leek, rather than garlic. The phytochemical volatiles evaluation indicated a higher proximity of elephant garlic to garlic, rather than leek, at least for the Chiana Valley specimen analyzed in this study.

Tracking the evolutionary history of the Allium ampeloprasum L. complex (section Allium) provides evidence of the contribution of North African diploids to the formation of allopolyploid horticultural groups

The economically important Allium ampeloprasum L. represents a polyploid complex, comprising hexa- and octoploid Great Headed Garlic horticultural cultivars (6x–8x GHG) and several traditional varieties of the tetraploid (4x) leeks (Leek, Bulbous leek, Kurrat and Pearl onion). Its wild representatives were indicated as rare in the Mediterranean region. This study aims to explore the diversity and origin of polyploidy in this complex, including its wild relatives A. baeticum Bossier and A. guttatum Steven with particular focus on the poorly investigated North-African region. Natural populations were sampled in Algeria in various bioclimatic conditions, then subjected to karyological and molecular phylogenetic analyses based on nuclear rDNA ITS region and chloroplast trnL–trnF and trnD–trnT intergenic spacers. Comparative analyses included available Genbank accession sequences representing old-world relatives. Chromosome count surveys revealed an unexpected higher occurrence of diploid (2n = 16) than tetraploid (2n = 32) cytotypes. The phylogenetic analyses first allowed positioning the Algerian material within the A. ampeloprasum complex. Interestingly, all the Algerian diploid and tetraploid populations from A. ampeloprasum and A. baeticum form a distinct monophyletic group. The results provide novel and robust evidence demonstrating that the North African diploid A. ampeloprasum genetic pool widely contributed as a source of progenitors not only for the A. ampeloprasum and A. baeticum Algerian tetraploids, but also in the formation of the GHG and Leek cultivated allopolyploids. Therefore, the North African populations emerge as an important reservoir of new wild genetic resources of great interest for tracing the origin of crop domestication and for breeding programs of cultivated varieties.

Effect of Three Planting Dates on Three Types of Garlic in Southwest Missouri

Commercial garlic (Allium sativum) is a relatively new crop for Missouri growers. While U.S. production is primarily in California, Oregon, Washington, and New York, little information is available regarding growing garlic in Missouri’s climate and soil conditions. Therefore, research is needed to investigate the optimum planting date for garlic in southwest Missouri. Comparisons between one spring and four fall planting dates using two garlic cultivars (Inchelium Red and German White) and the leek (Allium ampeloprasum) known as elephant garlic (A. ampeloprasum ssp. ampeloprasum) were planted at two replicated sites. Postharvest data were collected on bulb weight and diameter and clove weight and quantity. Although the numbers were not always statistically different, the overall results indicated that earlier planted garlic (September and early-October) had higher yields in 2016–17 than garlic planted later; however, in 2017–18, garlic planted in mid-October and early-November out-yielded garlic planted in September and early-October. Fall planting is preferred based on the results of our study, but spring-planted garlic can still yield a profitable crop for commercial growers. Future research on a variety of planting dates will give producers a better choice on when to plant in southwest Missouri.

Serological and molecular detection of Leek yellow stripe virus infecting onion (Allium cepa L.) and leek (Allium ampeloprasum L.) in Ankara, Turkey

Onion (Allium cepa L.) has a high economic value in Turkey and it is widely used as main ingredient in Turkish menus. During 2018, 25% of 1.930.695 tons onion production in Turkey was produced in Ankara province. Recently, virus-like symptoms had been observed on onion fields but so far there was no study on onion viral diseases in Ankara province. Leek yellow stripe virus (LYSV) mainly infects leek (Allium ampeloprasum L.) but also infects and potentially causes yield reduction on onion. In August 2018, 45 onion samples show typical viral infection symptoms such as leaf stripes, leaf malformation, yellowing, and dwarfing and six leek samples showing severe yellow leaf stripe were collected from fields in Ankara province. 6 onion and 2 leek samples were positive to LYSV infection in DAS-ELISA. Total nucleic acid was then extracted from samples to be used in RT-PCR using a pair of specific primer to amplify a fragment of LYSV CP region. 6 onion and 2 leek samples were also positive in the RT-PCR by forming specific bands of 1020 bp on agarose gel. The remaining samples did not produce any band on agarose gel, thus were evaluated as negative for LYSV infection. Phylogenetic analysis showed that LYSV Ankara isolates were most similar to isolates from Serbia, Argentina and Germany. This study confirmed LYSV infection in onion and leek for the first time in Ankara province, Turkey.

Carbon source dependent-anaerobic soil disinfestation (ASD) mitigates the sclerotial germination of Sclerotinia sclerotiorum

Though Sclerotinia sclerotiorum is a well-studied plant pathogen that causes significant economic damage worldwide, sustainable and environmental friendly control methods are difficult to establish due to it wide host range, cosmopolitan distribution and production of recalcitrant structures that can survive in soil for a long time. The pathogen was found causing a severe disease incidence on cabbage in 2016 in Sri Lanka. It was hypothesized that a) isolates of the recent disease outbreak display cross resistance to commonly applied fungicides and b) carbon (C) source supplemented Anaerobic Soil Disinfestation (ASD) is effective in mitigating the germination of sclerotia. In vitro fungicide sensitivity assays showed large variation in mycelial growth inhibition indicating high adaptability of the population towards environmental fluctuations and management practices. Signatures of cross resistance were evident. ASD was carried out using cabbage (Brassica oleracea) and leek (Allium ampeloprasum) cull piles, durian () peels and grass cuttings (Axonopus compressus) as C sources and determined the sclerotial viability. Cabbage and leek cull piles at rates of 60–100 mg/g soil completely inhibited sclerotial germination. Maintaining anaerobic condition along with C source amendments was found to be a critical step in mitigating the sclerotial germination. GC-MS analysis of the volatiles of cabbage leaves, leeks and durian further confirmed the presence of various bioactive compounds with potential antifungal activity. Therefore, in addition to elevated microbial activity in treatments, the volatiles of C sources may have helped mitigating sclerotial germination.

Green synthesized silver nanoparticle from Allium ampeloprasum aqueous extract: Characterization, antioxidant activities, antibacterial and cytotoxicity effects

In the current study for the first time, silver nanoparticles (AgNPs) were biosynthesized by reducing agents from hot water extract of Allium ampeloprasum, an antibacterial and anti-inflammatory edible plant. UV–vis. spectroscopy, Fourier transform infrared spectroscopy, dynamic light scattering, X-ray diffractometric, and transmission electron microscopy (TEM) analyses have been applied to confirm the formation of biosynthesized AgNPs. Total phenol content and antioxidant activities of AgNPs and extract together with their antibacterial and cytotoxic properties, were evaluated. According to TEM, AgNPs were spherical with a diameter of 8–50 nm. Total phenolic compounds were 15.58 μg/mL, and 10.94 μg/mL at a concentration of 150 μg/mL for the A. ampeloprasum extract and the biosynthesized AgNPs, respectively. Biosynthesized AgNPs showed significant antioxidant activity (81%) as compared to A. ampeloprasum extract (32%) and were active on multi-drug resistant P. aeruginosa. Besides, the cytotoxic activity response was also demonstrated that AgNPs were more potent than the A. ampeloprasum extract and showed high activity against Hela cell line with an IC50 value of less than 25 µg/mL. In conclusion, AgNPs synthesized by A. ampeloprasum extract with excellent antioxidant and antibacterial effects and acceptable cytotoxicity on cervical cancer cells have the potential to be used in biological applications.

Chemical Composition, Oxidative Stability, and Antioxidant Activity of Allium ampeloprasum L. (Wild Leek) Seed Oil.

Allium ampeloprasum L., commonly known as wild leek, is an edible vegetable that has been cultivated for centuries. However, no detailed studies have been undertaken to valorize A. ampeloprasum seed oil. This study aims to evaluate the physicochemical properties, chemical composition, and antioxidant activity of A. ampeloprasum seed oil. The seed oil content was found to be 18.20%. Gas chromatographymass spectrometry (GC-MS) showed that linoleic acid (71.65%) was the dominant acid, followed by oleic acid (14.11%) and palmitic acid (7.11%). A. ampeloprasum seed oil exhibited an oxidative stability of 5.22 h. Moreover, γ- and δ-tocotrienols were the major tocols present (79.56 and 52.08 mg/100 g oil, respectively). The total flavonoid content (16.64 µg CE /g oil) and total phenolic content (62.96 µg GAE /g oil) of the seed oil were also determined. The antioxidant capacity of the oil, as evaluated using the ABTS assay (136.30 µM TEAC/g oil), was found to be significant. These findings indicate that A. ampeloprasum seeds can be regarded as a new source of edible oil having health benefits and nutritional properties.

First report of Botrytis porri causing Botrytis leaf blight on leek in Japan

Leek (Allium ampeloprasum var. porrum) is a biennial vegetable species belonging to the family Liliaceae. In May 2011 and 2012, leaf spots and leaf blight on leek seedlings were observed in a greenhouse in Hokkaido, Japan. Leaf spot …

코끼리 흑마늘과 일반 흑마늘의 항산화 활성 비교

본 연구에서는 코끼리 마늘을 흑마늘로 제조할 때 변화하는 항산화 활성을 평가하고자 50% 에탄올에 추출한 후 기존의 일반 마늘 및 이를 숙성시킨 흑마늘과 비교 분석하였다. 코끼리 마늘의 추출 수율은 코끼리 흑마늘(57.43%)> 일반 흑마늘(39.39%)> 일반 마늘(29.00%)> 코끼리 마늘(26.82%)순으로 높았다. 코끼리 마늘에서 코끼리 흑마늘로 숙성 시 총 페놀 함량은 약 12.6배 늘어났고 총 플라보노이드 함량도 증가하였다. 항산화 효과를 측정한 결과 일반 마늘보다 코끼리 마늘이 흑마늘로 숙성하는 과정에서 더 큰 폭으로 활성이 증가하였다. 코끼리 마늘에서 코끼리 흑마늘로 숙성 후에 DPPH 라디칼 소거 활성은 약 30배나 높아졌으며, ABTS 라디칼 소거 활성은 약 11배 이상 증가하였다. FRAP 활성은 약 22배나 높아졌으며 환원력은 약 37배 증가하여 흑마늘로 숙성하였을 때 활성이 모두 큰 폭으로 증가하는 것을 확인할 수 있었다. 따라서 일반 마늘을 흑마늘로 숙성하는 것보다 코끼리 마늘을 흑마늘로 숙성할 때 항산화 활성이 더 증가하는 것으로 확인되었으며, 이러한 결과는 코끼리 마늘의 산업화에 기초자료로 활용될 수 있으리라 판단된다.

Comparative Study of Onion (Allium cepa) and Leek (Allium ampeloprasum): Identification of Organosulphur Compounds by UPLC-QTOF/MS and Anticancer Effect on MCF-7 Cells.

Onion (Allium cepa) and leek (Allium ampeloprasum var. porrum) are common herbs and vegetables found in our daily life. It belongs to the genus Allium, which is usually known for their high antioxidant and anticancer properties. Medical researchers highly recommend the exploitation of herbs and plants as alternative ways in the treatment of cancer. This research was designed to study the anticancer effects of onion and leek extracts on MCF-7 human breast cancer cell. Crude extracts of ethanol, methanol, and water of onion and leek were obtained by maceration. MCF-7 cells were cultured in complete media at 37°C and subjected to different treatments that involved varying concentrations (10, 50, and 100μg/mL) of onion and leek extracts for 24, 48, and 72h of incubation. The percentage of cell viability and the concentration of extracts on MCF-7 cells were determined using MTT assay. The water leek extract proved to be the most effective extract at 50μg/mL, whereby it showed a significant inhibition ability due to the presence of entadamide A-β-D-glucopyranoside as identified by ultra-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry (UPLC-QTOF/MS). Further studies about the mechanism of both extracts in causing cell death and the determination of the presence of other bioactive compounds in the extracts are needed.

Mercury Levels in Soil, Leafy Plants and Irrigation Well Water at Several Agricultural Fields in Baghdad Government, Iraq

Soil and plant contamination with heavy metals is one of the current problems in the world especially contamination with mercury. Heavy metals are very harmful because of their long biological half-lives, non-biodegradable nature and their possibility to accumulate at different body parts. Soil, well water and leafy plant samples (Apium graveoleus, Allium ampeloprasum, Lepidium sativum, Eruca sativa, Petroselinum hortense, Ocimum basilicum , Mentha pulegium) from three different agricultural fields (AL-Musafer village (site 1), AL-Autaifiyah (site 2) and AL-Huriyah (site 3)) in Baghdad government, Iraq were analyzed for mercury concentration. Hg level in soil samples ranged from 3.67 to 5.33 ppm in AL-Autaifiyah and AL-Musafer village, respectively. While, in water samples Hg level ranged from 1.2 in AL-Autaifiyah to 22.8 mg/l in AL-Musafer village. Plant samples recorded Hg level ranged from 0.009 to 2.88 ppm in AL-Autaifiyah and AL-Huriyah, respectively. The results showed that Hg level in water samples and most plant samples were above the acceptable limit according to WHO (1993), and FAQ/WHO (1999) respectively. While Hg level in soil samples was within the acceptable limit put by Ministry of the Environment, Finland (2007).

Antihypertensive Indigenous Lebanese Plants: Ethnopharmacology and a Clinical Trial.

Hypertension is highly prevalent among the Lebanese adult population and is indeed the major cause of mortality in Lebanon. Traditional use of antihypertensive medicinal plants has long been practiced. The aim of this study is to document this traditional knowledge and clinically test the antihypertensive capacity of three of the most commonly used wild plant species Mentha longifolia, Viola odorata and Urtica dioica. Ethno-pharmacological data was collected by personal interviews with herbalists and traditional healers using a semi structured survey questionnaire and assessing relative frequency of citation (RFC). The clinical study was conducted by a randomized, blind, placebo-controlled trial in 29 subjects with mild hypertension distributed in four groups, three plant extract treatments and one placebo. Systolic (SBP) and diastolic blood pressures (DBP) as well as mean arterial blood pressures (MAP) were monitored at weeks 4, 8, 12 and 16 during the treatment with 300 mL/day of plant extract. Results showed that M. longifolia, U. dioica and V. odorata exhibited the highest values of RCF (0.95) followed by Allium ampeloprasum (0.94), Apium graveolens (0.92) and Crataegus azarolus (0.90). The clinical trial revealed dose- and duration-dependent significant reductions in SBP, DBP and MAP of subjects treated with M. longifolia, U. dioica or V. odorata. Our findings indicate that extracts of these plants present an effective, safe and promising potential as a phyto-therapuetical approach for the treatment of mild hypertension. More research on the phytochemistry, pharmacological effects and the underlying mechanisms is necessary.

The Compromise of Intercropping: Biological Pest Control Versus Competition by Crop Species

Leek, Allium ampeloprasum L., is susceptible to attack by onion thrips, Thrips tabaci Lindeman, that reduce yield and quality. Intercropping has been proposed as a strategy for reducing negative effects of pests on one or all crops in a system. The objective of the study was to assess the effect of intercropping maize, Zea mays L., and leek on abundance of thrips and production and morphology of both crops, but emphasizing effects on leek. The experiment was done during spring 2016 in northwestern Mexico, under extreme climatic conditions characteristic of desert environments and high soil salinity. Two maize varieties (sweet and field) at zero, three, five, and 10 plants per square meter were intercropped with a fixed number of 10 leek plants per square meter. The response variables were thrips abundance and plant yields and morphology characteristics. Maize reduced abundance of thrips on leek, with 5.6, 2.6, 2.2, and 1.5 thrips for 0, 3, 5, and 10 maize plants m-2, respectively; i.e., the closer together the maize plants, the less abundant were thrips on leek, but leek yields were less with more maize plants (plant competition) per meter, with 12,075, 4,875, 4,581, and 4,159 kg ha-1, respectively. Leeks intercropped showed morphological adjustments compared with a leek monoculture, indicating negative effects of competition with maize, instead of benefiting from the microenvironment (cooler leek canopy temperatures) created by maize. Maize was effective at reducing abundance of thrips but severely out-competed leeks. Further testing is needed on less competitive secondary crop species in main crops in a region to reduce pest abundance naturally without decreasing yield potential of associated crops.