Allspice (Pimenta dioica) belongs to the order Myrtales and the family Myrtaceae (Tropicos, 2024); in Mexico, it is produced under rainfed conditions as a secondary crop, harvested from wild trees in forests, backyard orchards, as well as in pastures, live fences, windbreak barriers, or intercropped with other crops such as coffee (Coffea arabica), corn (Zea mays), orange (Citrus × sinensis), among others (Figure 1).

Figure 1

Harvesting of the fruit can begin as early as two years after the tree is established and is carried out mainly by hand, climbing the branches to collect the fruits when they are green or yellowish-green, followed by sun-drying (FHIA, 2016). In Mexico, this activity is mainly performed by Indigenous communities or native peoples, harvesting from scattered trees in home gardens, agroforestry systems, and live fences for self- consumption, while the surplus is sold as green allspice (Figure 2) (Machuca et al., 2020; Macía, 1998).

In 1996, in the state of Puebla, the cooperative Tosepan Titataniske set the price of fresh allspice at $2.50 pesos kg⁻¹ and dried allspice at $7.50 pesos kg⁻¹, exceeding the price of coffee cherries, which ranged from $1.70 to $2.80 pesos kg⁻¹. By 2020, the price of allspice as a seasoning ranged between $155.00 and $540.00 pesos kg⁻¹ (Machuca et al., 2020; Macía, 1998).

Figure 2

In 2022, allspice generated economic revenue of $161,377,940.00 pesos in Mexico, with a value ranging from $10,714.00 to $63,641.00 pesos t⁻¹; in 2023, the revenue was $153,210,640.00 pesos, with prices ranging from $10,655.00 to $66,862.00 pesos t⁻¹ (Table 1) (SIAP, 2024).

Table 1

State	2022		2023
	Production (t)	Value of production (thousands of pesos)	Production (t)	Value of production (thousands of pesos)
Veracruz	7,799.08	104,427.42	7,440.89	101,060.90
Puebla	1,174.10	12,580.03	1,147.71	12,229.23
Tabasco	975.05	30,684.49	901.64	25,988.78
Campeche	137.5	8,750.77	139.9	9,354.13
Chiapas	170.71	4,639.90	162.77	4,330.20
Oaxaca	8.9	295.33	7.1	247.4
Total	10,265.34	161,377.94	9,800.01	153,210.64

Prepared using data from SIAP (2024).

Allspice production in Mexico has increased in recent years; in 2011, 3,452 t were produced, while in 2023, production reached 9,800.01 t, representing a 183.9% increase (SIAP, 2024; Martínez et al., 2013). Currently, the top three producers nationwide are Veracruz, Puebla, and Tabasco, in that order. These states account for approximately 97% of total national production. Most of the production is exported to the United States (Table 1) (Martínez et al., 2013; SIAP, 2024).

The average yield of allspice is 54 kg per tree. In recent years, a small portion of production has been modernized (Macía, 1998; Martínez et al., 2013; Rojas-Pérez, 2017). However, it is estimated that more than 162,566 ha have high potential for cultivation, while 4,379,623 ha have medium productive potential, mainly in the area of the Trans- Mexican Volcanic Belt (INIFAP, 2012).

Martínez et al. (2013) note that to increase allspice production, plantations must be established in areas with favourable climatic conditions. The states with areas of high productive potential are Veracruz, Puebla, Hidalgo, San Luis Potosí, Guerrero, and Oaxaca (INIFAP, 2012). It is also necessary to develop pathogen-tolerant varieties; ensure proper tree nutrition; improve fruit harvesting methods, as it is currently done manually and often damages the tree; and modernize fruit drying techniques.

It is also important to develop agricultural technologies adapted to small, rugged plots and highly diversified production systems. In addition, phytosanitary issues must be addressed, as there are pathogens that affect allspice production (Esperón-Rodríguez et al., 2017). Likewise, it is essential to pursue sustainable allspice production, taking into account the three components of Nijkamp’s triangle: economic growth, social equity, and environmental sustainability (Zarta-Ávila, 2018).

Phytosanitary issues are often caused by a combination of environmental, economic, political, and social factors that impact agri-food production (Olvera-Vargas, 2022). In the case of allspice, there are few records of phytosanitary problems, their effects, causal agents, and control measures. However, in Mexico, there are reports of damage caused by Austropuccinia psidii, the agent responsible for rust, and Colletotrichum sp., which causes anthracnose (López and García, 2014; Morales-German et al., 2024; Velázquez- Silva et al., 2018).

Rust is the main phytosanitary problem affecting allspice, caused by Austropuccinia psidii (Pucciniales, Basidiomycota). This pathogen belongs to the phylum Basidiomycota, subphylum Pucciniomycotina, class Pucciniomycetes, order Pucciniales, suborder Uredinineae, and family Sphaerophragmiaceae (Mycobank, 2024). It is estimated to cause up to 50% crop loss and develops on the upper and lower leaf surfaces, flower buds, and petioles of young allspice leaves (FHIA, 2008; Morales-German et al., 2024; Rojas-Pérez, 2017). It is primarily associated with species of the Myrtaceae family and is commonly known as “guava and eucalyptus rust” because it also affects those species (López and García, 2014). In Brazil, it has been reported on guava (Psidium guajava), while in New Zealand it has been found on eucalyptus (Eucalyptus spp.) and native species (Metrosideros spp., Lophomyrthus spp., and Kunzea spp.) (Pathan et al., 2020). A. psidii poses a risk to agriculture, forestry, and native species in Mexico, as 192 species of the Myrtaceae family have been identified as susceptible to this pathogen (Esperón-Rodríguez et al., 2017).

Symptoms appear on both the upper and lower surfaces of the leaves, on young petioles, and on the fruits of the host, where circular spots develop ranging in color from purple to brown, with powdery pustules (amphigenous, caulicolous uredinia) that range from yellow to orange at the center of the spots, measuring 0.1-0.6 mm in diameter. These symptoms can cause fruit drop or a loss in fruit quality (Figure 3) (FHIA, 2008; López and García, 2014).

Figure 3

The signs of the pathogen appear as echinulate urediniospores (22.26 ± 3.08 × 16.03 ± 1.66 μm), hyaline to yellow, unicellular, and either pyriform, oval, or spherical in shape, with a truncated base (Figure 4) (López and García, 2014; Mohali and Aime, 2016; Morales-German et al., 2024).

Figure 4

Management of Austropuccinia psidii using antagonistic microorganisms

Management of rust in allspice is carried out mainly through cultural control (such as proper soil drainage and thinning of wild trees) and chemical control (Table 2) (FHIA, 2008; Martínez et al., 2013; Monroy-Rivera, 2011). However, in Mexico, there are no studies on the effectiveness of synthetic fungicides specifically for managing rust in allspice.

Table 2

Active ingredient	Trade name	Dose	Host	Country	Reference
Mancozeb	Dithane® 43 Sc, Manzate® 200	1 Kg/100 L of water	Pimenta gorda	Honduras	FHIA, 2008
Sulfato de cobre	-	1 Kg/100 L of water	Pimenta gorda	México	Martínez et al., 2013
Cobre	Phyton® 24 SC, Sulcox® 50 WP	50 mL per hectare	Pimenta gorda	Honduras	FHIA, 2008
Cobre	Nordox® 750 WG	0.5 g/500 mL of solution	Lophomyrtus x ralphii y Metrosideros excelsa	Australia	Pathan et al., 2020
Cyproconazole y Azoxystrobin Fosetyl aluminum	Amistar Xtar®	0.5 mL/500 Ml of solution	Lophomyrtus x ralphii y Metrosideros excelsa Lophomyrtus x ralphii y Metrosideros excelsa	Australia	Pathan et al., 2020
Fosetyl aluminum	Aliette® WG	1.25 mL/500 Ml of solution	Lophomyrtus x ralphii y Metrosideros excelsa Lophomyrtus x ralphii y Metrosideros excelsa	Australia	Pathan et al., 2021
Oxicloruro de cobre	Cupravit®	2 - 3 g/L of water	Pimenta dioica	México	Monroy-Rivera, 2011
Oxycarboxin	Plantvax® 750 WP	0.65 g/500 mL of solution	Lophomyrtus x ralphii y Metrosideros excelsa	Australia	Pathan et al., 2020
Tebuconazole	Folicur® 430 SC	0.15 mL/500 mL of solution	Lophomyrtus x ralphii y Metrosideros excelsa	Australia	Pathan et al., 2021
Triforine	Saporl®	0.5 mL/500 Ml of solution	Lophomyrtus x ralphii y Metrosideros excelsa	Australia	Pathan et al., 2022
Triadimenol	Bayfidan® 250	0.25 mL/500 mL of solution	Lophomyrtus x ralphii y Metrosideros excelsa	Australia	Pathan et al., 2023

Background information on the use of antagonistic microorganisms against A. psidii is limited; however, some microorganisms have been reported to reduce the incidence and act as potential biocontrol agents against rusts of the order Pucciniales, suggesting possible antagonistic effects against A. psidii (Table 3).

Table 3

Biocontrol agent	Phytopathogen	Host	Conditions	Country	Results	Reference
Bacillus megaterium and Paneibacillus xylanexedens	Stripe rust of wheat (Puccinia striiformis)	Wheat (Triticum sp.)	Natural environment (semi-field)	Pakistan	Decrease in severity (65.16 and 61.11 % respectively)	Kiani et al., 2021
B. subtilis (Serenade® ASO)	Yellow rust (P. striiformis)	Wheat (Triticum sp.)	Field trials	Denmark	Up to 60% control at moderate disease pressure was reported	Reiss y Jørgensen, 2017
Cladosporium sp.	White rust (P. horiana)	Chrysanthemum (Dendranthema grandiflora)	Laboratory and greenhouse	Mexico	Severity was reduced by 41% to 84%	García- Velasco et al., 2005
Cladosporium angulosum, C. anthropophilum, C. bambusicola and C. benschii, C. guizhouense, and C. macadamiae	Myrtle rust (Austropuccinia psidii)	Myrtaceae family	---	Brazil	Potential biocontrollers	Pereira et al., 2023
Cladosporium tenuissimum	Uromyces appendiculatus	Phaseolus vulgaris	in vitro in vivo	Italy	Reduction of 17 % of urediniospore germination. Severity decreased to 13 %.	Assante et al., 2004
Cladosporium sp., Alternaria sp. Aspergillus sp. and Trichoderma spp.	U. transversalis	Gladiolus (Gladiolus sp.)	in vitro	Mexico	Colonization percentages ranged from 41.7 to 60.2 %	Romero- Óran et al., 2016
Fusarium fujikuroi, Fusarium solani	Austropuccinia psidii	Malay Apple (Syzygium malaccense)	Laboratory	Brazil	Potential for hyperparasitism	Lopes et al., 2019
Lecanicillium spp., Calcarisporium sp., Sporothrix sp. and Simplicillium spp.	Coffee rust (Hemileia vastatrix)	Coffee (Coffea arabica)	in vitro	Mexico	The percentage of mycoparasitism ranged from 51.6 to 88.8 %	Gómez-De La Cruz et al., 2017
Simplicillium lanosoniveum	Puccinia graminis	Wheat (Triticum sp.)	Artificial climate chamber	China	Urediniospore germination rate of 17%, compared to 91% for the control.	Si et al., 2023
Simplicillium lanosoniveu and Phakopsora pachyrhizi	Phakopsora pachyrhizi	Soybean (Glycine max)	Laboratory and field trials	E.U.A.	The mean number of urediniums produced with the treatment was four times lower compared to the control.	Ward et al., 2012
Trichoderma barbatum and T. asperellum	P. horiana	Chrysanthemum (Chrysanthemum morifolium)	Plants in styrofoam cups	Mexico	Rust incidence ranged from 17 to 47 %.	García- Velasco et al., 2022

Recently, a study conducted in Brazil evaluated the effect of Bionectria ochroleuca, Cladosporium spp., and two isolates of Clonostachys rosea obtained from Metrosideros polymorpha, Eugenia reinwardtiana, and Syzygium jambos. However, only one of the C. rosea isolates reduced pustule formation by A. psidii and diseased tissue in Eugenia koolauensis (Chock et al., 2021).

Anthracnose caused by Colletotrichum sp. was first reported in Veracruz, Mexico, in 2018. It belongs to the phylum Ascomycota, subphylum Pezizomycotina, class Sordariomycetes, order Glomerellales, and family Glomerellaceae (Mycobank, 2024). This disease can cause production losses ranging from 20 to 50% during both pre- and post-harvest stages. Symptoms on the fruit include sunken brown or dark spots that lead to fruit necrosis (Figure 5) (Velázquez-Silva et al., 2018).

Figure 5

In a study conducted by Velázquez-Silva et al. (2018) in northern Veracruz, allspice fruits were collected, from which monospore cultures were obtained and later identified morphologically and molecularly as C. acutatum, C. gloeosporioides, C. fragariae, and

C. boninense.

Currently, there are no control strategies specifically for anthracnose in Pimenta dioica; however, there are precedents for the control of Colletotrichum sp. in other plant species using biorational products such as plant extracts (Allium sativum, Citrus sinensis and C. grandis, Swinglea glutinosa, Eucalyptus globulus, Piper auritum, Psidium guajava, and Urtica urens), biofungicides, defense inducers, genetic manipulation (Baños-Guevara et al., 2004; Gaviria-Hernández et al., 2013; Landero-Valenzuela et al., 2016), and the use of synthetic fungicides (Table 4).

Table 4

Active ingredient	Trade name	Dose	Host	Country	Reference
Azoxystrobin	Amistar® 50 WG	32 ppm, 250 mg L-1	Rubus glaucus, Carica papaya	Colombia, Mexico	Gaviria-Hernández et al., 2013; Santamaria et al., 2011
Benomyl	Benoagro® 50 WP, Benocor® Derosal® 500	125 ppm	Rubus glaucus	Colombia	Gaviria-Hernández et al., 2013
Carbendazim	SC, Rodazim® 500 sc	300 ppm	Rubus glaucus	Colombia	Gaviria-Hernández et al., 2014
Clorotalonil	Odeon® 720 SC	Recommended on the label 50ppm	Passiflora edulis, Carica papaya	Ecuador	Carreño et al., 2021
Difenoconazole	Difecor®	50 ppm	Rubus glaucus	Colombia	Gaviria-Hernández et al., 2013
Hidróxido de cobre	Kocide® 101	1230 ppm	Rubus glaucus	Colombia	Gaviria-Hernández et al., 2013
Mancozeb	Dithane M-45	1000 ppm	Mangifera indica	Venezuela	Rondón et al., 2006
Propiconazole	Bumper® 25 CE	Recommended on the label	Passiflora edulis, Carica papaya	Ecuador	Carreño et al., 2021
Procloraz	Funcloraz®	1000 ppm,112 mg L-1	Carica papaya, Mangifera indica	Venezuela, Mexico	Rondón et al., 2006; Santamaria et al., 2011
Pyraclostrobin	---	38.0 and 75.0 mg L-1 i.a	Citrus sinensis	Costa Rica	Guillén-Carvajal et al., 2023
Copper pentahydrate sulfate	Phyton®	Recommended on the label	Passiflora edulis, Carica papaya	Ecuador	Carreño et al., 2021
Tebuconazole	---	7.50 y 75.0 mg L- 1 i.a	Citrus sinensis	Costa Rica	Guillén-Carvajal et al., 2023
Tebuconazole + Triadimenol EC 300	Silvacur Combi® EC300	---	Selenicereus	Peru	Bello et al., 2022
Ferbam	---	1520 y 3040 mg L-1 i.a	Citrus sinensis	Costa Rica	Guillén-Carvajal et al., 2023

For the control of Colletotrichum sp., plant extracts from orange (Citrus sinensis), grapefruit (C. grandis), Swinglea lemon (Swinglea glutinosa), eucalyptus (Eucalyptus globulus), garlic (Allium sativum), and nettle (Urtica urens) have also been used (Gaviria- Hernández et al., 2013). Against Colletotrichum gloeosporioides in yam (Dioscorea spp.), the use of lemongrass (Cymbopogon citratus) essential oil has been reported (Pérez- Cordero et al., 2017). Other aqueous and ethanolic extracts used for this purpose include extracts from Capparis sinaica, Crotalaria aegyptiaca, Galium sinaica, Plantago sinaica, and Stachys aegyptiaca (Zakaria and Mohamed, 2020).

The effectiveness of antagonistic microorganisms (either endemic or from commercial products) for controlling Colletotrichum sp. isolated from and affecting various crops has also been reported, with their biocontrol potential evaluated both in vitro and in the field (Table 5).

Table 5

Biocontrol agent	Phytopathogen	Host	Conditions	Country	Results	Reference
Actinobacteria	C. capsici	Chili (Capsicum annuum)	Field trials	Indonesia	Decrease in severity and incidence by 100%.	Yanti et al., 2023
Bacillus amyloliquefaciens (Serenade ASO®)	C. gloeosporioides	Yellow pitaya of Huambo (Selenicereus megalanthus)	in vitro	Peru	Inhibited 100% of mycelial growth.	Bello et al., 2022
Bacillus amyloliquefaciens (Amylo-X®), T. gamsii y T. asperellum (Remedier®), B. amyloliquefaciens (Serenade® ASO), B. pumilus (Sonata®) and T. harzianum (Trianum-P®)	C. acutatum	Olive (Olea europaea)	in vivo	Greece	Inhibition in the production of conidia greater than 40%.	Varveri et al., 2024
Bacillus firmus	C. gloeosporioides	Papaya Maradol (Carica papaya)	in vitro	Mexico	Decreased pathogen growth by 75.32 and 69.17%.	Baños- Guevara et al., 2004
Bacillus subtilis and Rhodotorula minuta	C. gloeosporioides	Mango (Mangifera indica)	Field trial	Mexico	The combination of antagonists reduced the disease (severity of 8.0).	Carrillo et al., 2005
Bacillus sp., Streptomyces sp., Paenibacillus sp. and Gluconobacter cerinus	Colletotrichum sp.	Strawberry (Fragaria sp.) and blueberry (Vaccinium sp.)	in vitro	Mexico	Inhibition percentage from 67.0 to 97.5%.	Garay- Serrano and Pérez, 2024
Nigrospora spp.	C. gloeosporioides	Solanum betaceum	Bioassays	Ecuador	Decrease in damage and significant differences between treated plants versus control.	Delgado y Vásquez, 2010
Paenibacillus sp.	Colletotrichum sp.	Cocoa (Theobroma cacao)	in vitro y field tests	Mexico	Inhibited fungal growth by 30 to 50%. Decreased the incidence of anthracnose.	Rodríguez- Velázquez et al.,2025
Trichoderma asperellum, Trichoderma sp., T. virens (G-41®), T. harzianum (T-22®), Trichoderma sp. (Bactiva®) and Trichoderma sp. (Fithan®)	C. gloeosporioides	Passion fruit (Passiflora edulis)	in vitro	Mexico	The percentage of mycelial growth varied between 72.2 and 88.1%. The percentage of sporulation varied between 97.5 and 100%.	Ayvar- Serna et al., 2024
T. harzianum, T. viride, T. asperellum and Clonostachys rosea	Colletotrichum sp. and C. rosea	Mango (Mangifera indica)	in vitro	Perú	The Percentage Inhibition of Radial Growth Rate (PICR) ranged from 18.2 to 69.4%.	Goñas et al., 2017
Trichoderma lignorum (Mycobac®), Trichoderma harzianum (Agroguard®) and Bacillus subtilis	C. gloeosporioides and C. acutatum	Blackberry (Rubus glaucus)	in vitro	Colombia	Inhibition percentages between 26 and 79 %.	Gaviria- Hernández et al., 2013

Romero-Orán et al. (2016) reported that Cladosporium sp., Alternaria sp., Aspergillus sp., and Trichoderma spp. caused dehydration, degradation, and deformation of uredinia and urediniospores of Uromyces transversalis. They also observed hyphal invasion of Trichoderma sp. into uredinia of U. transversalis and did not rule out the production of antibiotics, secondary metabolites, and enzymes.

Assante et al. (2004) described the mechanisms of action involved in the mycoparasitism of Cladosporium tenuissimum on Uromyces appendiculatus, reporting enzymatic degradation of both external and internal layers of the urediniospore walls of

U. appendiculatus. They documented urediniospore penetration by short, septate, and highly branched hyphae of Cladosporium tenuissimum, leading to the disappearance of organelles in the urediniospores of U. appendiculatus. They also identified lytic activity during advanced stages of mycoparasitism, resulting in discoloration and thinning of the urediniospore walls, followed by hyphal growth and conidiophore formation on the urediniospores.

Ward et al. (2012) evaluated the biocontrol effect of Simplicillium lanosoniveum on soybean rust (Glycine max) caused by Phakopsora pachyrhizi, reporting changes in the color of uredinia, which may indicate a hypersensitive response of the antagonists against the pathogen.

In bacteria of the genus Bacillus, the mechanisms of action in the biocontrol of phytopathogens include the production of antimicrobial substances, competition for substrates, emission of volatile organic compounds, secretion of lytic enzymes, and induction of resistance (Pedraza et al., 2020). These mechanisms also involve the production of lipopeptides, siderophores, δ-endotoxins, and the activation of systemic acquired resistance (Villarreal-Delgado et al., 2018). A study conducted in Colombia found that the antibiotic Iturin A, produced by B. subtilis, inhibited the growth of Fusarium spp., demonstrating its potential as a phytopathogen control agent (Ariza and Sánchez, 2012). In vitro studies of B. subtilis against Fusarium solani and Pythium sp. showed that the bacterium produces biosurfactant compounds that enable it to exert antifungal activity by destabilizing the cell membranes of the phytopathogens (Sarti, 2019). However, Bacillus species must be assessed for biosafety. Although B. subtilis, B. licheniformis, and B. pumilus are not considered pathogenic to humans, there have been reported cases of foodborne intoxication associated with some species of the Bacillus cereus group (Villarreal-Delgado et al., 2018).

The main modes of action of Trichoderma sp. include competition for space and nutrients, mycoparasitism, and antibiosis, as well as the secretion of enzymes and the production of inhibitory compounds (Infante et al., 2009). Its antimicrobial activity against phytopathogenic fungi is primarily due to a combination of secondary metabolites (terpenes, peptaibols, pyrones, gliovirin, and gliotoxin) and hydrolytic enzymes. Trichoderma sp. also releases substances that induce systemic resistance responses and the expression of defense-related genes (Khan et al., 2020).

Worldwide, there are no studies on the use of antagonistic microorganisms to inhibit

A. psidii and Colletotrichum sp. in allspice. Research on native and endophytic microorganisms antagonistic to these phytopathogens represents a promising line of investigation in Mexico, where allspice agroecosystems remain vulnerable to outbreaks of anthracnose and rust.

It is essential to carry out studies that evaluate the effects of antagonistic microorganisms on the growth and development of Colletotrichum spp. and A. psidii, not only under in vitro conditions but also in terms of their impact on the epidemic development of the diseases under field conditions. These studies must also confirm that the microorganisms are not pathogenic to allspice, which would provide the basis for designing effective management strategies. Some of the microorganisms that could be evaluated include Bacillus spp., Cladosporium spp., Fusarium spp., Simplicillium spp., Trichoderma spp., Paenibacillus spp., Gluconobacter spp., Nigrospora spp., Clonostachys spp., and Streptomyces spp., which have been reported in the management of anthracnose and rust in other plant species.

In addition, it is necessary to deepen the investigation of the mechanisms of action that may be involved, conduct histological studies on the behaviour of antagonists in plant tissue, and perform biochemical analyses of potential secondary metabolites. The use of antagonistic microorganisms is proposed as a viable alternative for the sustainable production of allspice, given that its cultivation in Mexico takes place in diversified agroecosystems, where various plant and animal species coexist, including native species and potentially beneficial microorganisms with antagonistic potential.