# Efficacy of Four In Vitro Fungicides for Control of Wilting of Strawberry Crops in Puebla-Mexico
## 4 Discussion
[54] observed that, under in vitro conditions, it inhibited 100% of mycelial growth of _F. solani_, the causal agent of root rot in tomato, at a concentration of 0.044 g. Another study by [PERSON] et al. [55] reported that this pesticide inhibited 75.90% of mycelial growth of pathogens at a concentration of 1000 \(\upmu\)g mL\({}^{-1}\) in vitro. Both studies presented higher values than those reported in the present investigation. Fungicide Captan presents a fungitoxic compound because it affects energy transport in mitochondria and the physiological functioning of membranes in fungal cells, obstructing the activity of sulfhydryl enzymes and resulting in the release of thiophosgene (CSCI\({}_{2}\)), a highly toxic compound that kills pathogens [50]. The present study investigated the fungistatic ability of Chlorothalonif, which is a foliar fungicide with widespread use worldwide [56]. It is a non-systemic organochlorine fungicide. Specifically it is a broad-spectrum polychlorinated aromatic that causes mycelial-growth retardation and inhibits spore germination. It acts on respiration of fungal cells;that is, it binds to sulfhydryl groups of some amino acids that affect the Krebs cycle by reducing ATP synthesis, causing cell death [57]. Studies by [PERSON] et al. [58] reported that fungicide Chlorothalonil(r) reduced mycelial growth of _F. solani_ by 82.34%, in pathogens isolated from roots in eggplant crops, and these values are similar to those reported in the present investigation, considered moderately toxic on the IOBC [38] rating scale for the highest concentration (1350 mg L\({}^{-1}\)). [PERSON] et al. [59] reported that coriander root rot caused by _F. solani_ was controlled by fungicide Chlorothalonil(r) by 69.96%. A similar finding was observed by [PERSON] et al. [60] for _F. solani_, the causal agent of root rot in sweet orange, obtaining 62.82% mycelial-growth inhibition, with a concentration of 250 ppm, with values similar to those reported in the present investigation and considered slightly toxic on the IOBC [38] classification scale for the recommended concentration (900 mg L\({}^{-1}\)). For this reason, [PERSON] et al. [61] report its extensive use in strawberry cultivation under greenhouse conditions in Mexico. The disappearance of honey bees is only the most visible part of a widespread phenomenon due to massive loss of biodiversity that negatively impacts agroecosystems [62]. The fungicide Chlorothalonil has been shown to alter the intestinal bacterial communities of honey bees, in addition to decreasing larval survival in the live [63]. However, growers continue to rely on the chemical, without considering the negative effects for the future. According to the literature, Benonyml(r) is a systemic fungicide and is banned in developed countries., However, its use is very frequent in developing countries [64], as in the case of Mexico. It is a member of the benzimidazole class, which penetrates the fungal cell and reacts with proteins forming chelates; it also alters intracellular redox balance, inducing oxidative stress, and is a potent inhibitor of DNA synthesis in fungi [65,66]. Recently, [PERSON] et al. [67] reported 76% inhibition of mycelial growth of _F. solani_ (IRAN 11C) by 0.1 g/mL Benonyml under in vitro conditions on PDA medium. In this sense, [PERSON] et al. [68] also reported a reduction in mycelial growth on a strain of _F. solani_ from Ataturk University, obtaining 79.8% inhibition with a concentration of 1 mg/mL. However, [PERSON] et al. [69] observed that, under in vitro conditions, the fungicide Benonyml(r) (100 ppm) inhibited 100% mycelial growth of _F. solani_ (Fs-3), the causal agent of root rot on elephant-foot sweet potato. These values are like those reported in the present investigation, considered toxic on the IOBC [38] rating scale for the three concentrations used (Figures 4 and 5). Figure 5: The effect of four fungicides at different concentrations according to the classification scale established by IOBC.