Este camino sería increible continuar con este tipo de experimentos, a ver si conseguimos eliminar tantos fertilizantes que ponemos en nuestras vidas.
RESULTS AND DISCUSSION
Tomato plants treated with Staphysagria 12CH yielded fruits with higher diameter than those without intervention but it did not increase the weigh per plant.
Sulphur 12CH significantly reduced the number of fruits damaged by the small borer (Neoleucinodes elegantalis) (Table 1) but not the number of fruits damaged by the large borers. Sulphur 12CH did not differ from Bacillus thuringiensis kurstaki (Dipel®). Dipel is recommended by organic certifiers as being the best product to control large and small tomato borers (Dias, 1992). The effect of Sulphur on small borers was not confirmed in the second experiment, crop cycle 2009/2010 (Table 2). It can be argued that the dilution order makes the difference, since in 2008/2009 Sulphur was prepared by centesimal dilutions (CH) whereas in 2009/2010 was at decimal dilutions (DH). Also, none of the other high dilution preparations on decimal dilution order could reduce the fruit damage by borers (Table 2). However, it can differ from one homeopathic preparation to another and further studies are needed. In fact, centesimal and decimal dilutions are independent methods and different effects would be expected from them as indicated by Farmacopeia Homeopatica Brasileira (1997). The effect of high dilution preparations on insect pests was also reported by Deboni (2009). This author obtained 83 to 100% reduction on Acanthoscelides obtectus progeny when bean grains were treated with nosode of the own adult of A. obtectus.
Tomato plants treated by Sulphur 24DH in greenhouse conditions showed higher number of bunches but it did not differ from the non-intervention plot (Table 3). An increase in biomass is frequently reported by using homeopathic preparations. However, as stated by Bonato (2007), it is not always in linear response and the experiment design must include several possibilities of potential level and frequency. Carvalho et al. (2003) found that the level biomass production of Tanacetum parthenium treated by Arnica montana 1DH was higher than produced by plants treated by Arnica montana 3DH. Despite the fact that Sulphur 12DH and 24DH reduced the septoria leaf spot incidence, it was not significant probably due to high variance of data (Table 2). However, Toledo (2009) observed reduction levels of 35% and 17% of Alternaria solani incidence when applied Sulphur 12CH and 30CH, respectively. Sinha & Singh (1983) reported 100% efficiency of Sulphur 200CH on inhibition of the aflatoxin produced by Aspergillus parasiticus.
Tomato plants treated with Arnica montana 12DH showed increase of fruit weight at the level of 48.5% comparing to non-intervention (Table 2). Arnica montana 12DH and 24DH provided similar results in all evaluated variables. However, Arnica montana 12DH and 24DH did not differ from the control in relation to fruits damaged by borers and septoria leaf spot incidence in the field experiment. Under greenhouse conditions, Arnica montana at 12 DH and 24DH did not differ from the control for the number of fruit bunches, but it reduced the incidence and severity of septoria leaf spot (Table 3). Carvalho et al. (2003) observed that Arnica montana 1DH applied to T. parthenium plants increased 28% in biomass in comparison to plants treated with water.
Solanum aculeatissimum 24DH applied under field conditions could reduce the septoria leaf spot incidence on tomato plants, expressed by the curve under disease progress (ACDP), when compared to non-intervention. However, the high value of variance did not allow to detect significant differences among treatments (p>0.05) (Table 2). On the other hand, tomato plants under greenhouse conditions treated by nosodes of S. aculeatissimum 12DH and 24DH showed less incidence and severity of septoria leaf spot than non treated plants (Table 3). Rolim et al. (2005) observed that the nosode of A. solani at 30CH and 60CH reduced the severity of the own late blight on tomato plants under greenhouse conditions. The reduction of severity of A. solani on tomato was also reported by Toledo (2009) that used Ferrum sulphuricum 12CH and 30CH. The use of homeopathic preparations from wild ancestral plant species (Euchlaena mexicana) was studied by Almeida (2003). This author observed deleterious effect on Spodoptera frugiperda larvae feed on corn plants when applied Euchlaena at 6CH. In our studies, the high dilution preparations related specie S. aculeatissimum to tomato family did not affect genus pests nor the tomato yield (Table 2).
The tomato 12DH suppressed 100% infection of septoria leaf spot. At 24DH potential level, the tomato reduced also the incidence and severity of septoria leaf spot under greenhouse conditions in relation to other treatments (Table 3). However, plants treated by this high dilution preparation showed to delay the fruit maturation (data not presented). Moreover, tomato 24DH reduced more than 90% of septoria leaf spot severity in comparison to Bordeaux mixture that is largely used by organic farmers (Table 3). This trend also occurred in plants treated with the cupric formulation EEC. However, these results were not consistent under field conditions, where the tomato at 12DH or 24DH did not affect the tomato yield nor the insect damages and disease infection (Tabela 2). However, it seems that centesimal dilution (CH) would better discriminate the high dilution treatments on tomato crops than decimal dilution order (DH) and further studies should be done on that. On the other hand, attention should be devoted to high dilution effects from own tomato plants, which showed a potential to reduce septoria leaf spot under greenhouse conditions.
Unexpected result was observed by applying Arsenicum album 12CH. Tomato fruits produced by plants treated with this preparation were highly damaged by Helicoverpa zea, S. frugiperda, and S. eridania (Table 1). This can be interpreted as pathogenic response meanwhile the high dilution preparations stimulate host reaction in which come out artificial disorders (Bonato, 2007). Homeopathic pathogenic responses are manifestations from the interaction between the organisms and high dilution preparations, resulting in a temporary pathologic figure. Baiocco et al. (2008) observed also similar results by using Staphysagria 65CH on kale that increased the number of winged aphids. In our studies, Staphysagria 12CH increased also infection of Septoria lycopersici by comparing disease incidence with the control (Table 1). Nevertheless, the results are not the same for different conditions, as demonstrate by Rolim et al. (2005), who reported reduction on A. solani severity on tomato by applying Staphysagria 30CH. Inducing resistance could be one of the mode of action of high dilution on plants against diseases. This mechanism is well known with application of several chemical composts and it has been suggested by Bonato (2007) that would work on plants treated by high dilution preparations.
Despite the fact that B. thuringiensis is a traditional biological control product used against caterpillars, it did not differ from other treatments in our studies. Moreover, B. thuringiensis presented significant effect on reducing the incidence of septoria leaf spot (Table 1). Biological control agents namely bacteria and some fungus act throughout antibiosis that means they produce such kind of metabolites adverse to the other organism, being insects or parasites (Knaak et al., 2009). The antibiosis action of B. thuringiensis kurstaki on S. lycopersici is suggested because the low incidence of the infection on plants treated by the bacteria was consistent (Table 1). These results are supported by Knaak et al. (2007), that found the proteins Cry1Ab e Cry1Ac produced, respectively, by B. thuringiensis thuringiensis isolate 407 and B. thuringiensis kurstaki HD-73, to reduce the mycelia growth of Pyricularia grisea, Rhizoctonia solani, Fusarium oxysporum, and F. solani. Resmuska & Pria (2007) verified also reduction growth on Monilinia fructicola and Sclerotium rolfsii mycelia by B. thuringiensis and they prevented sclerotia formation.
Bordeaux mixture at 0.3% could reduce more than 50% of septoria leaf spot incidence comparison to the control plants in greenhouse conditions (Table 3). This result was consistent in the field experiments, where the septoria leaf spot incidence was reduced by 90% on the crop cycle 2009/2010 (Table 2). Nevertheless, Bordeaux mixture was not better than high dilution preparation to manage diseases and pests on tomato crops.
In conclusion, we may state that high dilution preparations have the potential to replace Bordeaux mixture, a traditional formulation largely used by organic farmers. Despite its well known insecticidal action, B. thuringiensis showed to have deleterious effect on phytopathogenic fungus. The high dilution Sulphur 12CH can be used to protect tomato fruits against the small borer damage.