<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE article  PUBLIC "-//NLM//DTD Journal Publishing DTD v3.0 20080202//EN" "http://dtd.nlm.nih.gov/publishing/3.0/journalpublishing3.dtd"><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" dtd-version="3.0" xml:lang="en" article-type="research article"><front><journal-meta><journal-id journal-id-type="publisher-id">AJPS</journal-id><journal-title-group><journal-title>American Journal of Plant Sciences</journal-title></journal-title-group><issn pub-type="epub">2158-2742</issn><publisher><publisher-name>Scientific Research Publishing</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.4236/ajps.2023.144029</article-id><article-id pub-id-type="publisher-id">AJPS-124312</article-id><article-categories><subj-group subj-group-type="heading"><subject>Articles</subject></subj-group><subj-group subj-group-type="Discipline-v2"><subject>Biomedical&amp;Life Sciences</subject></subj-group></article-categories><title-group><article-title>
 
 
  Fungal Flora on Weeds in the Cashew (&lt;i&gt;Anacardium occidentale&lt;/i&gt; L.) Orchard in C&#244;te d’Ivoire
 
</article-title></title-group><contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Traoré</surname><given-names>Aboulaye</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref></contrib><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Soro</surname><given-names>Sibirina</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref></contrib><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Ayemou</surname><given-names>A. R. Emmanuella</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref></contrib><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Traoré-Ouattara</surname><given-names>Karidia</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref></contrib><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Kouabenan</surname><given-names>Abo</given-names></name><xref ref-type="aff" rid="aff2"><sup>2</sup></xref></contrib><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Koné</surname><given-names>Daouda</given-names></name><xref ref-type="aff" rid="aff3"><sup>3</sup></xref></contrib></contrib-group><aff id="aff1"><addr-line>Laboratory for the Improvement of Agricultural Production, UFR Agroforestry,  Université Jean Lorougnon Guédé, Daloa, C&amp;amp;#244;te d’Ivoire</addr-line></aff><aff id="aff2"><addr-line>Laboratory of Phytopathology and Plant Biology, Department of Training and Research in Agriculture and Animal Resources, Institut National Polytechnique Félix Houphou&amp;amp;#235;t-Boigny (INPHB), Yamoussoukro, C&amp;amp;#244;te d’Ivoire</addr-line></aff><aff id="aff3"><addr-line>African Centre of Excellence on Climate Change, Biodiversity and Sustainable Agriculture (CEA-CCBAD), Université Félix Houphou&amp;amp;#235;t-Boigny (UFHB), Abidjan, C&amp;amp;#244;te d’Ivoire</addr-line></aff><pub-date pub-type="epub"><day>07</day><month>04</month><year>2023</year></pub-date><volume>14</volume><issue>04</issue><fpage>448</fpage><lpage>463</lpage><history><date date-type="received"><day>2,</day>	<month>February</month>	<year>2023</year></date><date date-type="rev-recd"><day>14,</day>	<month>April</month>	<year>2023</year>	</date><date date-type="accepted"><day>17,</day>	<month>April</month>	<year>2023</year></date></history><permissions><copyright-statement>&#169; Copyright  2014 by authors and Scientific Research Publishing Inc. </copyright-statement><copyright-year>2014</copyright-year><license><license-p>This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/</license-p></license></permissions><abstract><p>
 
 
  Since 2015, C&amp;#244;te d’Ivoire has been the world’s largest cashew producer. However, cashew orchards in C&amp;#244;te d’Ivoire are infected by fungal diseases that weaken
   production. And the contribution of weeds to the spread of these diseases is not yet understood. This study was initiated with the aim of establishing the role of weeds in the proliferation of pathogenic fungi in orchards. It consisted of a survey of weeds showing disease symptoms in cashew orchards in C&amp;#244;te d’Ivoire from February 2021 to July 2022. The itinerant method was used for the weed inventory. Symptomatic leaves were collected and sent to the laboratory for diagnosis on PDA (Potatoes Dextrose Agar) medium. In total, 50 species in 46 genera and 23 families were recorded. Laboratory diagnosis of the samples showed that 80% of the weeds identified harboured pathogenic fungi. The highest infection rates were obtained on Danielia oliveri R. (99.33% to 100%), Vitellaria paradoxa G. (100%), Pterocarpus erinaceus P. (83.91% to 99.33%), Micuna pruriens L. (98.33% to 100%) and Isoberlinia doka C. et S. (56.33% to 100%). The diagnosis revealed the presence of Lasiodiplodia sp, Colletotrichum sp, Pestalotia sp, Alternaria sp and Curvularia sp on weeds in the cashew orchard in C&amp;#244;te d’Ivoire.
 
</p></abstract><kwd-group><kwd>Weed</kwd><kwd> Infection Rate</kwd><kwd> Symptoms</kwd><kwd> Cashew</kwd><kwd> C&amp;#244;te d’Ivoire</kwd></kwd-group></article-meta></front><body><sec id="s1"><title>1. Introduction</title><p>Cashew (Anacardium occidentale L.) is an Angiosperm in the class Dicotyledonous in the order Sapindaceae, which contains 73 genera and about 600 species [<xref ref-type="bibr" rid="scirp.124312-ref1">1</xref>] . Native to Brazil, the cashew is currently cultivated in more than 32 countries around the world. However, the vast majority of marketed production is concentrated in four major areas, namely Southeast Asia, West Africa, East Africa and Brazil [<xref ref-type="bibr" rid="scirp.124312-ref2">2</xref>] . Africa produces about 40% of the total raw nuts in the world and 80% of the production is obtained in West Africa with over 2,901,825 ha of plantations [<xref ref-type="bibr" rid="scirp.124312-ref3">3</xref>] [<xref ref-type="bibr" rid="scirp.124312-ref4">4</xref>] . C&#244;te d’Ivoire has been the world’s leading producer and exporter of raw cashew nuts since 2015. Indeed, Ivorian cashew nut production has undergone a spectacular evolution. Production has risen from 235,000 tonnes in 2006 to 968,676 tonnes of raw cashew nuts in 2021, an increase of 14% compared to 2020 [<xref ref-type="bibr" rid="scirp.124312-ref5">5</xref>] .</p><p>Cashew tree cultivation and exploitation contribute to the socio-economic development of several countries in the world [<xref ref-type="bibr" rid="scirp.124312-ref6">6</xref>] [<xref ref-type="bibr" rid="scirp.124312-ref7">7</xref>] . In rural areas, the cashew sector is a powerful lever in the fight against poverty and unemployment. This crop has become the main source of income for the population and facilitates the schooling of children in rural areas. In addition, cashew products are full of nutritional and therapeutic benefits. Cashew kernel consumption is an excellent way to reduce the risk of cardiovascular disease [<xref ref-type="bibr" rid="scirp.124312-ref8">8</xref>] . Cashew apples are very rich in vitamin C polyphenolic compounds [<xref ref-type="bibr" rid="scirp.124312-ref9">9</xref>] [<xref ref-type="bibr" rid="scirp.124312-ref10">10</xref>] [<xref ref-type="bibr" rid="scirp.124312-ref11">11</xref>] [<xref ref-type="bibr" rid="scirp.124312-ref12">12</xref>] and have a very diverse carotenoid profile [<xref ref-type="bibr" rid="scirp.124312-ref13">13</xref>] . It is also used for wine and vinegar production [<xref ref-type="bibr" rid="scirp.124312-ref14">14</xref>] .</p><p>Unfortunately, the productivity of cashew orchards is compromised by numerous phytosanitary problems. In addition to pests, more than a dozen diseases have been described on cashew [<xref ref-type="bibr" rid="scirp.124312-ref15">15</xref>] . Among these diseases, anthracnose (Colletotrichum gloeosporio&#239;des), pestalotiose (Pestalotia heterocornis) and bud rot (Lasiodiplodia theobromae) are responsible for significant damage in the cashew orchard in C&#244;te d’Ivoire [<xref ref-type="bibr" rid="scirp.124312-ref16">16</xref>] . He found that symptoms of these diseases are also present on weeds in the orchard. These weeds could be alternative hosts of fungal pathologies in the orchard. Despite the importance of cashew in the Ivorian economy, there is very little data on the presence of alternative weed hosts of cashew fungal diseases in the orchard. However, knowledge of these alternative host weeds can help to implement a sustainable control strategy against cashew fungal diseases. This study was initiated to establish the role of weeds in the spread of pathogenic fungi in cashew orchards. The aim was to characterize symptomatic weeds and then to identify the pathogenic fungi they harbour.</p></sec><sec id="s2"><title>2. Material and Method</title><sec id="s2_1"><title>2.1. Study Areas</title><p><xref ref-type="fig" rid="fig1">Figure 1</xref> illustrates the different study zones, namely the Northern agro-ecological zone, the Central agro-ecological zone, the Eastern agro-ecological zone and the Central-Western agro-ecological zone.</p><p>The Northern agro-ecological zone is characterized by a Sudanese climate with two seasons. The dry season runs from November to April and the rainy season from May to October. Average temperatures vary between 24˚C and 33˚C. The average annual rainfall is between 1100 and 1600 mm. The vegetation in this zone is savannah.</p><p>The eastern agro-ecological zone is characterised by a tropical climate with a very hot and dry period from November to February and a rainy period from March to October. The average annual temperature in this zone is 26.4˚C and rainfall averages 850.8 mm. The vegetation is essentially tree and shrub savannah with gallery forests.</p><p>The climate of the Central agro-ecological zone is of the Baulean type, characterised by a very hot and dry period from November to February and a rainy period from March to October. The average annual temperature varies between 26˚C and 34˚C. The average annual rainfall varies between 745.4 mm and 1580 mm. The vegetation is dominated by savannah trees.</p><p>The Centre-West agro-ecological zone is characterised by a mountain climate with four seasons. The long rainy season starts in April and ends in mid-July, while the short dry season lasts from mid-July to mid-September. The short rainy season runs from mid-September to mid-November and the long dry season from December to March. The dry and wet seasons alternate with temperatures ranging from 24.65˚C to 27.75˚C on average. Almost the entire basin is in the tropical rainforest zone with dense forest vegetation.</p></sec><sec id="s2_2"><title>2.2. Material</title><p>The plant material used in this study consisted of leaves of weeds showing disease symptoms in the cashew orchard. The technical equipment consisted of a GPS, a camera, pruning shears and sterile bags. In the laboratory, PDA medium, an autoclave, a laminar flow hood and an electronic balance were used.</p></sec><sec id="s2_3"><title>2.3. Methods</title><sec id="s2_3_1"><title>2.3.1. Collection of Samples</title><p>Surveys were conducted in orchards in four agro-ecological zones of the Ivorian cashew basin from February 2021 to July 2022. In each agro-ecological zone, ten orchards of one hectare in size were randomly selected. The itinerant method was used for the inventory of weeds showing disease symptoms in the orchard. The method consisted of walking the orchard in a diagonal direction. Weeds with disease symptoms found elsewhere in the orchard were added to the list. During this survey, the name and morphological type of weeds showing disease symptoms were determined. Attacked organs were collected with pruning shears which were immediately cleaned with 70% alcohol after sampling. The samples collected consisted mainly of leaves. These samples were stored in envelopes and coded and sent to the laboratory for diagnosis on PDA (Potatoes Dextrose Agar) medium.</p></sec><sec id="s2_3_2"><title>2.3.2. Isolation and Purification of Fungi</title><p>In the laboratory, samples showing the characteristic symptoms of anthracnose, desiccation and pestalotiose were selected for diagnosis. Riviera’s method has been modified and used [<xref ref-type="bibr" rid="scirp.124312-ref17">17</xref>] . Each sample was thoroughly washed with tap water and dried on blotting paper. After drying, the samples were cleaned with 70% alcohol. Then, 3 - 4 millimetre explants were taken from the growth front of the symptoms using a sterile scalpel. The sampling equipment was automatically cleaned with 70% alcohol after each sample. Explants from the same sample were then soaked in 5% sodium hypochlorite for 3 minutes before being rinsed three times in succession with sterile distilled water and dried on blotting paper in an aseptic environment. Seeding of the explants was done under a laminar flow hood near the flame of the benzene burner. It consisted of placing four explants of the same sample equidistantly in a Petri dish containing frozen PDA medium. The Petri dishes were sealed with para film, coded (reference and date) and then incubated at a temperature of 27˚C &#177; 2˚C until proliferation of the fungal colonies.</p><p>The purification of the fungal colonies was done under the same aseptic conditions as the inoculation. A fragment of the mycelium was removed from the outgrowth zone of the fungal colony and transplanted into the centre of a new Petri dish containing frozen PDA medium. Pure fungal isolates were obtained from successive purifications [<xref ref-type="bibr" rid="scirp.124312-ref18">18</xref>] . The fungal isolates obtained from the diagnosis were identified according to their macroscopic characteristics on PDA medium and microscopic characteristics according to the identification key of [<xref ref-type="bibr" rid="scirp.124312-ref19">19</xref>] .</p></sec><sec id="s2_3_3"><title>2.3.3. Weeds Infection Rate</title><p>A weed is said to be infected if the diagnosis reveals the presence of at least one fungus on a sample from one of its organs showing disease symptoms. The infection rate was calculated according to the following formula:</p><p>Ti ( % ) = ( NEp / NtE ) * 1 00 (1)</p><p>With:</p><p>Ti: Infection rate of a weed,</p><p>NEp: Number of samples testing positive and</p><p>NtE: Total number of weed samples showing disease symptoms.</p></sec><sec id="s2_3_4"><title>2.3.4. Frequency of Fungi</title><p>Walder’s formula was used to calculate the isolation frequency of fungi [<xref ref-type="bibr" rid="scirp.124312-ref20">20</xref>] :</p><p>Fi ( % ) = ( Ni / Nti ) * 1 00 (2)</p><p>With:</p><p>Fi: Frequency of isolation in percentage.</p><p>Ni: Number of isolations of one fungal genus in all samples.</p><p>Nti: Total number of isolations of all fungal genera.</p></sec><sec id="s2_3_5"><title>2.3.5. Data Processing</title><p>Microsoft Excel 2013 spreadsheet software was used for data entry and graph construction. Statistica version 7.1 was used for statistical analysis of the data. Normality was checked before the data were subjected to analysis of variance (ANOVA). When differences were significant at the 5% level, comparison of means by the Newman-Keuls test was performed.</p><p>QGIS software version 3.28.0 was used to produce the Study Area Map.</p></sec></sec></sec><sec id="s3"><title>3. Results and Discussion</title><sec id="s3_1"><title>3.1. Results</title><sec id="s3_1_1"><title>3.1.1. Observed Symptoms</title><p>The study conducted on weed symptomatology in the cashew orchard in C&#244;te d’Ivoire identified 50 species divided into 46 genera and 23 families. The most represented family was the Fabaceae. Weeds showing disease symptoms in the cashew orchard belonged to two classes, namely Dicotyledons (76%) and Monocotyledons (24%). The main symptoms identified were of four types. These included necrosis on the leaves, beach-like spots in the form of burning, desiccation and deposits of red or whitish powder on the leaves (<xref ref-type="fig" rid="fig2">Figure 2</xref>). Laboratory diagnosis of the samples showed that 80% of the weeds identified harboured cashew pathogenic fungi in the orchard in C&#244;te d’Ivoire. The infected weeds were</p><p>distributed among three morphological types, namely shrubs (65%), lianas (25%) and herbaceous plants (10%).</p></sec><sec id="s3_1_2"><title>3.1.2. Weed Infection Rate in Cashew Orchard According to Agro-Ecological Zones</title><p><xref ref-type="fig" rid="fig3">Figure 3</xref> shows the infection rate of weeds showing disease symptoms in the cashew orchard in C&#244;te d’Ivoire. The weed infection rate varies according to the agro-ecological zones. ANOVA tests showed that there was no significant difference (F = 1.96 and P = 0.12) between weed infection rates in the different agroecological zones surveyed. However, the highest infection rate (79.12%) was obtained in the Central agroecological zone. In contrast, the lowest weed infection rate was obtained in the Eastern agro-ecological zone. Intermediate infection rates of 63.51% and 60.15% were obtained in the North and Centre-West agroecological zones respectively.</p></sec><sec id="s3_1_3"><title>3.1.3. Weed Infection Rate in the Agro-Ecological Zones According to Species</title><p>The infection rate within the agro-ecological zones varies according to the weeds identified. The ANOVA test performed at the 5% level showed that there was a highly significant difference (F = 14.35 and P = 0.000) between the weed infection rates within each agroecological zone.</p><p>The highest weed infection rates in the eastern agro-ecological zone were obtained on Daniellia oliveri R. (100%), Micuna pruriens L. (100%), Vitellaria paradoxa G. (100%) and Albizia zygia M. (99%). Intermediate infection rates were obtained on Bridelia ferruginea B. (87.13%), Terminalia schimperiana H. (75.25%), Diospiros mespiliformis H. (45.33%) and Calepogonium mucunoides Desv. In contrast, Centroseuma pubescens B. and Ficus sur F. had the lowest infection rate (25.75%) in the eastern agro-ecological zone. The infection rate was zero for the weeds Anchomanes diformis Bl., Stylochiton hypogaeus Lepr. and Synedrella nodiflora L. (<xref ref-type="fig" rid="fig4">Figure 4</xref>).</p><p>Weed infection rates in the Central agro-ecological zone varied from 25.66%</p><p>to 100%. The highest infection rates were obtained on Daniellia oliveri (100%), Isoberlinia doka C. et S. (100%), Vitellaria paradoxa G. (100%), Pterocarpus erinaceus P. (99.33%) and Micuna pruriens L. (99.26%). While Calepogonium mucunoides Desv. had the lowest infection rate (25.66%) in the Central agroecological zone. In this zone, no fungi were isolated from the weeds Pseudocedrela kotchyi Sch. and Tacca leontopetaloides L. (<xref ref-type="fig" rid="fig5">Figure 5</xref>).</p><p>The infection rate of the weeds in the northern agro-ecological zone varied from 25.75% to 100%. The highest infection rates were obtained on Daniellia oliveri R. (100%), Vitellaria paradoxa Gaertn. (100%), Isoberlinia doka Craib. et Stapf. (98.86%) and Piliostigma thonningii Schumach (87.22%). The species Vitex doniana S. had the lowest infection rate (25.75%) in the Northern agro-ecological zone. In this zone, intermediate infection rates were recorded for the species Terminalia schimperiana H. (78.66%), Bridelia ferruginea B. (77.54%), Erythrina senegalensis DC. (75.66%), Nauclea latifolia Smith. (70.60%) and Saba senegalensis A. DC. (67.66%). The infection rate was zero for the weeds Anona senegalensis Pers., Hymenocardia acida Tul. and Setaria barbata Lam (<xref ref-type="fig" rid="fig6">Figure 6</xref>).</p><p>In the Centre-Ouest agro-ecological zone, infection rates of weeds showing disease symptoms in orchards varied from 20.56% to 99.33%. The highest infection rates were obtained on Daniellia oliveri R. (99.33%), Micuna pruriens L. (95.33%) and Vitex doniana S. (95%). On the other hand, the species Millettia zechiana Harms. had the lowest infection rate (20.56%) in the Centre-Ouest agro-ecological zone. The infection rate was zero for the weeds Calepogonium</p><p>mucunoides Desv. and Panicum maximum Jacq. (<xref ref-type="fig" rid="fig7">Figure 7</xref>).</p></sec><sec id="s3_1_4"><title>3.1.4. Fungal Flora on Weeds</title><p>Samples taken from weeds showing disease symptoms in the cashew orchard were subjected to laboratory diagnosis. This diagnosis revealed that five species of fungi, namely Lasiodiplodia sp, Colletotrichum sp, Pestalotia sp, Alternaria sp and Curvularia sp are present on weeds in the cashew orchard in C&#244;te d’Ivoire. These mycopathogens were identified on the basis of morphological characters on the PDA culture medium and under the microscope. Three of the species identified were common on shrubs and vines in the four agroecological zones surveyed (<xref ref-type="fig" rid="fig8">Figure 8</xref>).</p><p>The other two, Alternaria sp and Curvularia sp, were occasionally found on shrubs and grasses in the Central-Western and Northern agro-ecological zones of C&#244;te d’Ivoire (<xref ref-type="fig" rid="fig9">Figure 9</xref>).</p></sec><sec id="s3_1_5"><title>3.1.5. Frequency of Fungi</title><p><xref ref-type="fig" rid="fig1">Figure 1</xref>0 shows the frequency of isolation of the three most frequent fungi on weeds in the cashew orchard in C&#244;te d’Ivoire. The graph shows that the species Colletotrichum sp was the most frequent in all agro-ecological zones. Furthermore, the frequencies of Colletotrichum sp (47.5% to 55.25%), were statistically identical for all agro-ecological zones. In contrast, the isolation frequencies of Pestalotia sp (10.5% to 22.5%) were the lowest in all agro-ecological zones. The isolation frequencies of Lasiodiplodia sp (30% to 40.33%) were intermediate in all agro-ecological zones.</p><p>The analysis within each agro-ecological zone shows that there is a significant difference between the isolation frequencies of the different fungus species. In fact, in the Northern agro-ecological zone, the highest frequency (47.5%) was obtained by Colletotrichum sp. and the lowest frequency (22.25%) was obtained by Pestalotia sp. In the Central agro-ecological zone, the highest frequency</p><p>(55.25%) was obtained by Colletotrichum sp. While Pestalotia sp. had the lowest frequency of isolation (10.5%). The highest frequency of isolation (47.5%) in the agroecological zone Centre-West was obtained by Colletotrichum sp. While, the lowest frequency (17.25%) was obtained by Pestalotia sp. In the agroecological zone East, the highest frequency of isolation (47.51%) was obtained by Colletotrichum sp. And Pestalotia sp had the lowest frequency of isolation (12.16%).</p></sec></sec><sec id="s3_2"><title>3.2. Discussion</title><p>The results showed that fungi are present on weeds in the cashew orchard in C&#244;te d’Ivoire. The infection rate of the weeds surveyed was 80%. This high infection rate indicates that the majority of the symptoms observed on weeds in the cashew orchard are due to fungal attacks. The main symptoms identified were necrosis spots on the leaves, beach spots in the form of burning, desiccation and red or white powdery deposits on the leaves. The high presence of these symptoms on weeds in the cashew orchard is thought to be related to the presence of Colletotrichum gloeosporioides, Lasiodiplodia theobromae, Pestalotia heterocornis, Cephaleuros virescens or O&#239;dium anacardii. These symptoms are identical to those described on cashew by several authors in previous studies. The necrosis spots evolving into a beach-like burn on cashew leaves are caused by Colletotrichum gloeosporioides. And the red powdery deposits on cashew leaves were described as a symptom of red rust caused by Cephaleuros virescens on cashew [<xref ref-type="bibr" rid="scirp.124312-ref21">21</xref>] . Similarly in Cameroon, cashew powdery mildew is manifested by the appearance of whitish colonies on the upper leaves [<xref ref-type="bibr" rid="scirp.124312-ref22">22</xref>] . In Burkina Faso, Lasiodiplodia theobromae is responsible for mango tree desiccation [<xref ref-type="bibr" rid="scirp.124312-ref23">23</xref>] . Pestalotia heterocornis causes leaf necrosis spots in cashew in C&#244;te d’Ivoire [<xref ref-type="bibr" rid="scirp.124312-ref24">24</xref>] .</p><p>At the level of morphological type, results showed that shrubs with an infection rate of (65%) were the most infected in the cashew orchard. This could be explained by the fact that the shrubs have a tissue structure similar to that of cashew. These plants, which are essentially made of lignin, would be compatible to the same fungal pathogens. This high rate for shrubs would also be due to the fact that the latter benefit from a relatively longer presence time than the other morphological types in the orchard. This time would be sufficient for the pathogenic fungi to establish a compatibility relationship with the shrubs. Some shrubs in the cashew orchard have food or medicinal functions [<xref ref-type="bibr" rid="scirp.124312-ref25">25</xref>] .</p><p>Diagnosis of symptomatic samples identified five species of fungi, namely Colletotrichum sp, Lasiodiplodia sp, Pestalotia sp, Curvularia sp and Alternaria sp. According to several authors the fungal genera identified are responsible for cashew tree diseases in different producing countries [<xref ref-type="bibr" rid="scirp.124312-ref26">26</xref>] [<xref ref-type="bibr" rid="scirp.124312-ref27">27</xref>] [<xref ref-type="bibr" rid="scirp.124312-ref28">28</xref>] . They are said to be capable of attacking all cashew organs. In C&#244;te d’Ivoire, C. gloeosporioides has been identified as responsible for anthracnose on all cashew organs [<xref ref-type="bibr" rid="scirp.124312-ref26">26</xref>] . The species L. theobromae, is involved in the drying of cashew buds bitten by helopeltis sp in C&#244;te d’Ivoire [<xref ref-type="bibr" rid="scirp.124312-ref27">27</xref>] . In Burkina Faso, C. gloeosporioides, P. heterocornis and Alternaria sp have been identified on cashew leaves [<xref ref-type="bibr" rid="scirp.124312-ref28">28</xref>] . Furthermore, these authors reported that Curvularia sp is associated with disease symptoms on cashew nut and cashew apple.</p><p>C. gloeosporioides and L. theobromae were the most frequent species in all agroecological zones. This could be explained by the diversity of host plants of these two species in the cashew orchard. This frequency would also reflect the ability of these fungi to adapt to different agroclimatic conditions. C. gloeosporioides and L. theobromae are associated with mango desiccation in four provinces belonging to different agroclimatic zones in Burkina Faso [<xref ref-type="bibr" rid="scirp.124312-ref29">29</xref>] .</p><p>The presence of alternative weed hosts of anthracnose and desiccation in the orchard is a threat to cashew production in C&#244;te d’Ivoire. Indeed, in Mozambique, the yield losses due to cashew anthracnose are between 50% and 70% [<xref ref-type="bibr" rid="scirp.124312-ref30">30</xref>] . The bud desiccation alone can cause cashew yield losses of 70% and the death of more than 50% of vegetative shoots [<xref ref-type="bibr" rid="scirp.124312-ref31">31</xref>] . Furthermore, the results highlight the indirect harmfulness of weeds in the cashew orchard in C&#244;te d’Ivoire. A similar study showed that weeds maintain phytoviruses in Solanaceae crops in C&#244;te d’Ivoire [<xref ref-type="bibr" rid="scirp.124312-ref32">32</xref>] .</p></sec></sec><sec id="s4"><title>4. Conclusion</title><p>At the end of this study, it was found that the cashew orchard harbours a diversity of weeds hosts of cashew pathogenic fungi in C&#244;te d’Ivoire. The symptoms observed were anthracnose, desiccation, mildew/oidium rust and pestalotiosis. The overall infection rate of weeds showing these symptoms in the orchard was 80%. And the most infected weeds in the cashew orchard were Daniellia oliveri, Vitellaria oliveri, Pterocarpus erinaceus, Micuna pruriens, Albizia zygia and Bridelia ferruginea. Furthermore, the study revealed the presence of Colletotrichum sp, Lasiodiplodia sp, Pestalotia sp, Curvularia sp and Alternaria sp on weeds. The results of this study are interesting and deserve to be deepened by a molecular characterization of the fungi obtained and the realization of transmission tests of the fungi between the infected weeds and the cashew trees.</p></sec><sec id="s5"><title>5. Significance Statement</title><p>This is the first study carried out on alternative weed hosts of cashew pathogenic fungi in the cashew orchard in C&#244;te d’Ivoire. The results of this study show that the cashew orchard in C&#244;te d’Ivoire harbours alternative weed hosts of pathogenic fungi.</p></sec><sec id="s6"><title>Acknowledgements</title><p>The authors would like to thank the Fonds Interprofessionnel pour la Recherche et le Conseil Agricoles ( FIRCA ), the Projet de Promotion de la Comp&#233;titivit&#233; de la Cha&#238;ne de valeur de l’Anacarde ( PPCA ), the Conseil du Coton et de l’Anacarde (CCA), the Programme National de Recherches sur l’Anacarde (PNRA), for their financial support. We also thank the Agricultural Production Improvement Laboratory of the University Jean Lorougnon Gu&#233;d&#233; of Daloa for the equipment.</p></sec><sec id="s7"><title>Conflicts of Interest</title><p>The authors declare no conflicts of interest regarding the publication of this paper.</p></sec><sec id="s8"><title>Cite this paper</title><p>Aboulaye, T., Sibirina, S., Emmanuella, A.A.R., Karidia, T.-O., Abo, K. and Daouda, K. (2023) Fungal Flora on Weeds in the Cashew (Anacardium occidentale L.) Orchard in C&#244;te d’Ivoire. American Journal of Plant Sciences, 14, 448-463. https://doi.org/10.4236/ajps.2023.144029</p></sec></body><back><ref-list><title>References</title><ref id="scirp.124312-ref1"><label>1</label><mixed-citation publication-type="other" xlink:type="simple">Purseglove, J.W. (1968) Tropical Crops: Dicotyledons, Longman Scientific and Technical. John Wiley and Sons Inc., New York.</mixed-citation></ref><ref id="scirp.124312-ref2"><label>2</label><mixed-citation publication-type="other" xlink:type="simple">RONGEAD (2013) Conna&amp;#238;tre et comprendre le marché international de l’anacarde. 49.</mixed-citation></ref><ref id="scirp.124312-ref3"><label>3</label><mixed-citation publication-type="other" xlink:type="simple">Monteiro, F., Romeiras, M.M., Figueiredo, A., Sebastiana, M., Baldé, A., Catarino, L. and Batista, D. (2015) Tracking Cashew Economically Important Diseases in the West African Region Using Metagenomics. Frontiers in Plant Science, 30, Article 482. https://doi.org/10.3389/fpls.2015.00482</mixed-citation></ref><ref id="scirp.124312-ref4"><label>4</label><mixed-citation publication-type="other" xlink:type="simple">FAOSTAT (2020) Base des données de la FAO 2020.  
http://faostat3.fao.org./20-05-2020.</mixed-citation></ref><ref id="scirp.124312-ref5"><label>5</label><mixed-citation publication-type="other" xlink:type="simple">CCA (2022) L’ouverture de la campagne 2022 de commercialisation de la noix de cajou. Abidjan.</mixed-citation></ref><ref id="scirp.124312-ref6"><label>6</label><mixed-citation publication-type="other" xlink:type="simple">Balogoun, I., Sa&amp;#239;dou, A., Ahoton, E.L., Amadji, G.L., Ahohuendo, B.C., Adebo, I.B., Babatounde, S., Chougourou, D., Adoukonou-Sagbadja, H. and Ahanchede, A. (2014) Caractérisation des systèmes de production à base d’anacardier dans les principales zones de culture au Bénin. Agronomie Africaine, 26, 9-22.</mixed-citation></ref><ref id="scirp.124312-ref7"><label>7</label><mixed-citation publication-type="other" xlink:type="simple">Bezerra, M.A., de Lacerda, C.F., Filho, E.G., de Abreu, C.E.B. and Prisco, J.T. (2007) Physiology of Cashew Plants Grown under Adverse Conditions. Brazilian Journal Plant Physiology, 19, 449-461. https://doi.org/10.1590/S1677-04202007000400012</mixed-citation></ref><ref id="scirp.124312-ref8"><label>8</label><mixed-citation publication-type="other" xlink:type="simple">Piepoli, M.F., et al. (2016) Main Messages for Primary Care from the 2016 European Guidelines on Cardiovascular Disease Prevention in Clinical Practice. European Journal of General Practice, 24, 51-56.  
https://doi.org/10.1080/13814788.2017.1398320</mixed-citation></ref><ref id="scirp.124312-ref9"><label>9</label><mixed-citation publication-type="other" xlink:type="simple">Assun&amp;#231;&amp;#227;o, R.B. and Mercadante, A.Z. (2003) Carotenoids and Ascorbic Acid Composition from Commercial Products of Cashew Apple (Anacardium occidentale L.). Journal of Food Composition and Analysis, 16, 647-657.  
https://doi.org/10.1016/S0889-1575(03)00098-X</mixed-citation></ref><ref id="scirp.124312-ref10"><label>10</label><mixed-citation publication-type="other" xlink:type="simple">Abreu, F.A., Perez, M., Dornier, M. and Reynes, M. (2005) Potentialités de la microfiltration tangentielle sur membranes minérales pour la clarification du jus de pomme de cajou. Fruits, 60, 33-40. https://doi.org/10.1051/fruits:2005010</mixed-citation></ref><ref id="scirp.124312-ref11"><label>11</label><mixed-citation publication-type="other" xlink:type="simple">Brito, B., Rodriquez, M., Samaniego, I., Jaramillo, I.M. and Vaillant, F. (2008) Characterising Polysaccharides in Cherimoya (Annona cherimola Mill.) Purée and Their Enzymatic Liquefaction. European Food Research and Technology, 226, 355-361.  
https://doi.org/10.1007/s00217-006-0545-0</mixed-citation></ref><ref id="scirp.124312-ref12"><label>12</label><mixed-citation publication-type="other" xlink:type="simple">Michodjehoun-Mestres, L. (2009) Etude des composés phénoliques de la pomme cajou (Anacardium occidentale L.) Biochimie, chimie et technologie alimentaire. Thèse de Doctorat, Université Montpellier II, Montpellier.</mixed-citation></ref><ref id="scirp.124312-ref13"><label>13</label><mixed-citation publication-type="other" xlink:type="simple">Abreu, F.A. (2012) Etude d’un procédé intégrant la microfiltration tangentielle pour la production d’extraits concentrés en caroténo&amp;#239;des à partir de pommes de cajou. Sciences des procédés-Sciences des aliments, Thèse de Doctorat, Université de Montpellier II, Montpellier.</mixed-citation></ref><ref id="scirp.124312-ref14"><label>14</label><mixed-citation publication-type="other" xlink:type="simple">Soro, D. (2012) Couplage de procédés membranaires pour la clarification et la concentration du jus de pomme de cajou: Performances et impacts sur la qualité des produits. Thèse de doctorat, du Centre International d’Etudes Supérieures en Sciences Agronomiques, Montpellier.</mixed-citation></ref><ref id="scirp.124312-ref15"><label>15</label><mixed-citation publication-type="other" xlink:type="simple">NARI (2009) Naliendele Agricultural Institute. Diseases and Insect Pests of Cashew. Technical Report, Naliendele, 62.</mixed-citation></ref><ref id="scirp.124312-ref16"><label>16</label><mixed-citation publication-type="other" xlink:type="simple">Koné, D., Abo, K., Fatogoma, S., Soro, S., Camara, B. et N’Guessan, A.C. (2015) Etablissement de la carte sanitaire du verger anacardier, contr&amp;#244;le et veille sanitaire en c&amp;#244;te d’ivoire. Rapport d’exécution du projet entre le Conseil du Coton et de l’Anacarde et le Laboratoire de Physiologie Végétale de l’Université Félix Houphou&amp;#235;t-Boigny d’Abidjan, 303.</mixed-citation></ref><ref id="scirp.124312-ref17"><label>17</label><mixed-citation publication-type="other" xlink:type="simple">Rivera-Vargas, L.I., Yanaliz, L.N., McGovern, R.J., Seijio, T. and Davis, M.J. (2006) Occurrence and Distribution of Colletotrichum spp. on Mango (Mangifera indica L.) in Puerto Rico and Florida, USA. Plant Pathology Journal, 5, 191-198.  
https://doi.org/10.3923/ppj.2006.191.198</mixed-citation></ref><ref id="scirp.124312-ref18"><label>18</label><mixed-citation publication-type="other" xlink:type="simple">N’Guettia, M.Y., Diallo, A.H., Kouassi, N. and Coulibaly, F.C. (2013) Diversité morphologique et pathogénique des souches de Colletotrichum sp. responsables de l’anthracnose de la mangue en C&amp;#244;te d’Ivoire. Journal of Animal &amp; Plant Sciences, 18, 2775-2784.</mixed-citation></ref><ref id="scirp.124312-ref19"><label>19</label><mixed-citation publication-type="other" xlink:type="simple">Barnett, H. and Barry, B.H. (1972) Illustrated Genera of Imperfect Fungi. Burgess Publishing In., Minneapolis.</mixed-citation></ref><ref id="scirp.124312-ref20"><label>20</label><mixed-citation publication-type="other" xlink:type="simple">Walder, M. (1996) Statistique et calcul des probabilités. 7th Edition, Dalloz, Paris.</mixed-citation></ref><ref id="scirp.124312-ref21"><label>21</label><mixed-citation publication-type="other" xlink:type="simple">Afouda, L.C.A., Zinsou, V., Balogoun, R.K., Onzo, A. and Ahohuendo, B.C. (2013) Inventaire des agents pathogènes de l’anacardier (Anacardium occidentale L.) au Bénin. Bull. Rech. Agron. Bén., 73, 13-19.</mixed-citation></ref><ref id="scirp.124312-ref22"><label>22</label><mixed-citation publication-type="other" xlink:type="simple">Dooh, N.J.P., Asta, D.B.C., Djile, B., Tchoupou, T.B.D., Heu, A., Mboussi, B.S., Kuate, T.N.W. and Ambang, Z. (2021) Principales maladies fongiques des anacardiers (Anacardium occidentale L.) au Cameroun. Journal of Agricultural Science, 13, 124-134. https://doi.org/10.5539/jas.v13n3p124</mixed-citation></ref><ref id="scirp.124312-ref23"><label>23</label><mixed-citation publication-type="other" xlink:type="simple">Dianda, Z.O. (2019) Caractérisation des agents pathogènes associés au dessèchement du manguier et essai de méthode de lutte contre la maladie au Burkina Faso. Thèse de doctorat, Unique de l’Université Joseph KI-ZERBO, Ouagadougou.</mixed-citation></ref><ref id="scirp.124312-ref24"><label>24</label><mixed-citation publication-type="other" xlink:type="simple">Nakpalo, S., Soro, S., Koné, T., Kouabenan, A., Koné, M. and Koné, D. (2017) Champignons parasites dans les vergers d’anacardiers (Anacardium occidentale L.) de C&amp;#244;te d’Ivoire. Plant Pathology Journal, 16, 82-88.  
https://doi.org/10.3923/ppj.2017.82.88</mixed-citation></ref><ref id="scirp.124312-ref25"><label>25</label><mixed-citation publication-type="other" xlink:type="simple">Konaté, L.M., Ouattara, D.N., Kouamé, F.N’G. and Bakayoko, A. (2021) Diversity and Uses by Farmers of Cashew (Anacardium occidentale L.) Orchards Weeds in C&amp;#244;te d’Ivoire. Ethnobotany Research &amp; Applications, 21, Article No. 21.  
https://doi.org/10.32859/era.21.21.1-14</mixed-citation></ref><ref id="scirp.124312-ref26"><label>26</label><mixed-citation publication-type="other" xlink:type="simple">Soro, S., Silué, N., Ouattara, G.M., Chérif, M., Camara, I., Sorho, F., Ouali, N.M., Abo, K., Koné, M. and Koné, D. (2015) Investigations on Major Cashew Diseases in C&amp;#244;te d’Ivoire. Proceedings of the Third International Cashew Conference, Dar Es Salaam, 16-19 November 2015, 158-166.</mixed-citation></ref><ref id="scirp.124312-ref27"><label>27</label><mixed-citation publication-type="other" xlink:type="simple">Soro, S., Sanogo, S., Ouattara, M., Silue, N., Koné, D. and Kouadio, J. (2020) Analyse descriptive et facteurs agronomiques d’avant-garde de l’état sanitaire des vergers anacardiers (Anacardium occidentale L.) en C&amp;#244;te d’Ivoire. European Scientific Journal, 16, 72-86. https://doi.org/10.19044/esj.2020.v16n30p72</mixed-citation></ref><ref id="scirp.124312-ref28"><label>28</label><mixed-citation publication-type="other" xlink:type="simple">Wonni, I., Sereme, D., Ouedraogo, I., Kassankagno, A.I., Dao, I., Ouedraogo, L. and Nacro, S. (2017) Diseases of Cashew Nut Plants (Anacardium occidentale L.) in Burkina Faso. Advances in Plants &amp; Agriculture Research, 6, 78-83.  
https://doi.org/10.15406/apar.2017.06.00216</mixed-citation></ref><ref id="scirp.124312-ref29"><label>29</label><mixed-citation publication-type="other" xlink:type="simple">Dianda, Z.O., Wonni, I., Zombré, C., Traoré, O., Sérémé, D., Boro, F., Ouédraogo, I., Ouédraogo, S.L. and Sankara P. (2018) Prévalence du dessèchement du manguier et évaluation de la fréquence des champignons associés à la maladie au Burkina Faso. Journal of Applied Biosciences, 126, 12686-12699.  
https://doi.org/10.4314/jab.v126i1.6</mixed-citation></ref><ref id="scirp.124312-ref30"><label>30</label><mixed-citation publication-type="other" xlink:type="simple">Mathur, S.B. and Kongsdal, O. (2003) Common Laboratory Seed Health Testing Methods for detecting fungi. 1st Edition, International Seed Testing Association, Switzerland.</mixed-citation></ref><ref id="scirp.124312-ref31"><label>31</label><mixed-citation publication-type="other" xlink:type="simple">Loganathan, M. and Vanitha, K. (2016) Management of Diseases in Cashew. In: Integrated Pest Management in Cashew, Lecture Notes 2016. ICAR-Directorate of Cashew Research Puttur-574 202, Dakshina Kannada Karnataka, 21-23.</mixed-citation></ref><ref id="scirp.124312-ref32"><label>32</label><mixed-citation publication-type="other" xlink:type="simple">Traoré, K., Sorho, F., Dramane, D.D. and Sylla, M. (2013) Adventices h&amp;#244;tes alternatifs de virus en culture de Solanaceae en C&amp;#244;te d’Ivoire. Agronomie Africaine, 25, 231-237.</mixed-citation></ref></ref-list></back></article>