The cultivation of garlic (Allium sativum L.) in Aguascalientes and Zacatecas is the most important vegetable during the winter; about 3 000 hectares are cultivated in both states (^{Reveles et al., 2014}; ^{Macias et al., 2014}). Because the garlic propagation system is exclusively clonal or vegetative the seed can carry a large number of pathogens (^{Cafrune et al., 2006}). Pathogens present externally or internally in the seed can cause seed abortion, seed rot, reduction or elimination of germination capacity or tissue damage of emergent plants (^{Fakhrunnisa and Ghaffar, 2006}).

During the production process and in post-harvest the plants or bulbs of garlic are affected by a group of pathogens that can be disseminated through the seed (^{Ochoa et al., 2012}). Little is known about the presence of fungal pathogens and the abiotic damage present in garlic bulbs used as seeds in Aguascalientes and Zacatecas. Therefore, the objective of the study was to determine the incidence of fungi and mites in different commercial varieties and experimental garlic in Aguascalientes and Zacatecas.

During May and June of 2015, a variable number of bulbs of different garlic cultivars were collected from producer and experimental plots in the municipality of Pabellon de Arteaga and Tepezala, Aguascalientes, and at Villa of Cos and Calera, Zacatecas, all collected bulbs had been harvested in the period April - June 2015.

The bulbs were kept in paper bags during July and August; in September the healthy and damaged teeth of each bulb were weighed, counted and weighed. Subsequently, each tooth of a bulb was examined under a stereoscopic microscope to detect mites, as well as the presence of mycelium in the red lesions present or on the inner catheles of each bulbil. The identification of mites and fungi was carried out according to the descriptive characteristics published by ^{Estebanes and Rodríguez (1991)}; ^{Watanabe (1994)} respectively.

It was possible to collect garlic of 25 cultivars of the types white, mottled, pink and purple; the majority of the bulbs collected came from the municipalities of Pabellon of Arteaga and Tepezala in Aguascalientes.

The presence of fungi and mites was detected in brown to red bulb lesions although fungal colonies were frequently found on the surface of the seed without obvious damage. In three collections (Chilean, Hermosillo and Silver) no lesions, fungal colonies or mites were observed. On the contrary, the collections with the highest percentage of damage were Durango, C-3-1/25 and R-35-10-1B with 30.9, 27.1 and 25% respectively.

It is important to note that collections such as Massone, Nacajuca, Ixmiquilpan, Oaxaca and Guatemala presented variable damages due to a “sunken lesion” of variable color between coffee and red without fungal growth or presence of mites, which was called “chemical damage”, a similar damage to the “waxy breakdown” that has been reported affecting mainly the outer bulbs of garlic that are subjected to high temperature before harvest (^{Schwartz, 1995}) (Table 1).

Table 1 Percentage of damage and organisms associated with lesions on garlic teeth of different cultivars. 

U= Ulocladium spp.; R= Rhizoglyphus spp.; C= Curvularia spp.; A= Alternaria spp.; S= Stemphyllium spp.; Rh= Rhizoctonia spp.; F= Fusarium spp.; V= Verticillium spp.; P= Penicillium spp.; DQ= degradación química; DM= daño mecánico.

It was generally found that the most common pathogen was Ulocladium spp. 40% of the collections in association with other fungi such as Curvularia spp., Verticillium spp. and Fusarium spp. among others, Ulocladium sp. has been reported in barley seed (^{Fakhrunnisa and Ghaffar, 2006}).

Several species of Fusarium affecting garlic seed with damage between 50-60% (^{Crowe, 1995}) have been reported in Aguascalientes ^{Velasquez and Medina (2004)} reported the pathogenicity of Fusarium spp. on some varieties of garlic. Although the presence of Rhizoctonia spp. in garlic culture remains (^{Sumner, 1995}), probably its occurrence in this work is associated with the cathallas that cover the teeth. The chemical damage was the most frequent abiotic symptom, 52% of the collections were recorded and it is possible that in advanced stages of damage, it serves as a gateway to saprophytes present in the bulb cathallas.

The mite Rhizoglyphus spp. was detected in five of the collected collections (Table 1), on the other hand, the presence of the Aceria tulipae K., which has been reported in bulbs collected in the states of Aguascalientes, Guanajuato and Zacatecas (^{Acuña, 2007}; ^{Acuña et al., 2012}), was not detected in the present work.

No sclerotia or mycelium of Sclerotium cepivorum Berk., causal agent of white rot of garlic and considered as the main disease of the crop in this region were found (^{Velásquez et al., 2011}), neither were bulbs damaged by Ditylenchus dipsaci Kühn in any of the varieties sampled.

The damage assessment revealed that only eight (32%) of the 25 collections contained damaged seeds. The highest damage, expressed as a percentage of the total weight with some type of injury were Durango, Calerense and Spanish with 11.7, 6.6 and 6.1% of the total body weight (Table 2).

Table 2 Weight loss (%) in bulbs with damaged teeth in 25 garlic collections from Aguascalientes and Zacatecas.