The in-field observations were carried out in a period of 20 months in Corpoica R.C. La Selva, Rionegro, Antioquia, under conditions of a Lower Montane moist forest (LM-mf). 12 treatments were applied to blackberry plants of the San Antonio ecotype, originated in vitro. The evaluated treatments were the following: T1: Trichoderma harzianum+Trichoderma koningii (commercial product of Hongos del Trópico), T2: Trichoderma sp. (comercial product of Bioprotección), T3: Trichoderma koningiopsis (Th003 Trichoderma, product of CORPOICA), T4: Trichoderma asperellum (Th034 Trichoderma, product of CORPOICA ), T5:Trichoderma asperellum (T-30 Trichoderma, product of the Corporación para Investigaciones Biológicas - CIB, in scaling process), T6: Trichoderma asperellum (T-98 Trichoderma, product of the CIB, in scaling process), T7: Burkholderia cepacia (Botrycid, commercial product of Safer), T8: extract of Swinglea glutinosa (EcoSwing® commercial product of Ecoflora), T9: corresponds to the traditional treatments of the farmer based on the applications of chemical products with active ingredients such as (Mancozeb) and (Propamocarb), T10: Application of chemical products (the products with the following active ingredients were applied: (Mancozeb), (Mandipropamida), (Carbendazim), (Propamocarb), (Metalaxil+Mancozeb) alternating according the effect and incidence of the blackberry diseases, T11: Application of chemical products alternating with biological products (bio-control microorganisms and vegetal extracts) according to the recommendations of the suppliers and the phenological state of the plants; the following products were applied: extract of Swinglea glutinosa, Burkholderia cepacia, Trichoderma koningiopsis (Th003), Trichoderma asperellum (T-98), Trichoderma sp., Propamocarb, Metalaxil +Mancozeb, Mandipropamida, taking into account the presence and incidence of the diseases, T12: Absolute control, no treatment was applied to the plants. The 12 treatments were distributed in three completely randomized blocks, each plant was an experimental unit and each treatment was made of five experimental units.

The plants that underwent the treatment were surrounded by blackberry plant sources of inoculum, for a total of 270 plants sown with a distance of 2 m x 2 m between plants and 3 m x 3 m between furrows, in an area of 1530 m² (Díaz, 2009; Hincapié, 2010). Previous to the crops' establishment, a chemical analysis of the soil was made which was used as a base to the fertilization process. The cultural labors proper to the crops were made such as the plateo (keeping the young plants clear of weeds), weed control, pruning, wiring on a modified double T trellis system, maintenance pruning (leaving 5 stems per plant), sanitary pruning, and destruction of the pruning remainders. The plot was monitored on a weekly basis and the application of the treatments started once a 50% of the plants were blossomed. These applications were carried out every 15 days, using the doses recommended by the products manufacturers and traders. The evaluations were carried out every eight days, by collecting and separating the healthy fruits from the sick on each type of treatment in order to be quantified in the laboratory later on through the processes of counting, weighing, classification and registry of the fruits affected by the diseases. The following were taken into consideration: the amount of healthy fruits and their weight, the number of fruits affected by the gray mold (Botrytis cinerea), downy mildew or peronospora (Peronospora sp.), and the anthracnose (Colletotrichum sp.). For each of the treatments the performance per treatment (kg ha^-1) was estimated. For the mentioned variables, an analysis of variance and the medians separation according to the Tukey test on a 5% level were conducted. Besides, the cost of the different treatments was calculated and the gross profit was estimated per hectare sown (1666 plants). The experiment was suspended once the plants reached the 11 month of the productive stage (the peak or production under the agro-ecological conditions where the plot was established is reached 18 months after the beginning of the productive stage) (Díaz, 2009; Hincapié, 2010).

The results obtained through this research are the following: on the Absolute Control treatment (T12), the treatments that showed a higher percentage of healthy fruits, with no significant statistical differences, by the gray mold, downy mildew and Anthracnose diseases (Figure 1) were: T11, T10, T3 and T9 (Table 1). For this group of treatments, the percentage of sick fruits was between 35 and 39%; whereas the Absolute Control group presented an 81% of sick fruits. In this same group of treatments, the best results for the gray mold management were achieved with the use of T3 and T11 (with percentages between the 2.2 and 2.5%) in contrast to the Control group that presented a 15%. For the downy mildew the percentage of sick fruits was between the 32.3 and 36%, being the best treatments the T10, T11 and T9 in contrast to the Control group which presented a 64.2% (Table 1). Regarding the Anthracnose, the percentage of affected fruits was less than 2.1%. Treatment T8 did not show any difference from the Absolute Control T12, but both presented differences from the rest of treatments (Table 1).

Figure 1

Table 1

In addition to this, after analyzing all treatments, and independently the behavior of the diseases, the following was observed: for the gray mold the best treatments were the T1, T3 and T11 which presented the lowest percentage of fruits affected by the disease (2.2% to 2.5%) (Table 1); to this group the treatments that followed are T7, T5, T10, T4 and T8 with percentages between the 3 and 4% of the fruits affected by the disease with no significant differences between them. Treatments T6, T9 and T12 were the less efficient. Treatment T12 showed significant differences from all treatments and reached the highest percentage of fruits affected by Botrytis cinerea, corresponding to a 15%. Figure 1A illustrated the symptoms of the fruit affected by gray mold, these are consistent to a soft rot in which appears a growth of grayish color that corresponds to the sporulation of the fungus.

Regarding the downy mildew, this was the disease that showed the high percentages of affected fruits (32% to 64%). With treatments T10, T11, T9, the lowest percentages of sick fruits were obtained, around 32% (Table 1). For the other treatments the percentage of sick fruits was between the 36 and 52.7%. Some significant differences were established with the Absolute Control group, which reach a 64% of fruits with symptoms of the disease. This disease manifests with bad filled drupes, uneven ripening, irregular development (Figure 1B), and the fruits harden when touched.

Regarding the Anthracnose, this disease showed the lower percentage of affected fruits (less than 2.1%) Other studies have reported losses by Anthracnose estimated in approximately a 5% of the fruits affected by different diseases (Tamayo, 2009). In the fruits the disease appears sporadically and the symptoms correspond to drupes dehydration, necrosis (Figure 1C), and wet rot with presence of fungal structures (Saldarriaga and Bernal, 2000).

During this study, besides the behavior of the diseases in front of the different treatments, the production (kg of healthy fruits per treatment ha^-1), the production costs (assuming $2000 COP as the sale value of a kilo of blackberry), and the cost of the treatment were considered. Table 2 registers the respective values and costs for each of the treatments.

Table 2

The highest production (t ha^-1 per year) was reached on treatments T10, T9 and T11; however, when the costs analysis was made, it showed that the value of consumables for some treatments was considerable and affected negatively the profit; leading in some moments to produce losses, like can be seen on treatment T9.

T11 (chemical products alternating with biological products and vegetal extract) was considered as a promising treatment due to the gross profit and the possibility of reducing the charge of chemical products and the addition of biological products, which can contribute to the environmental conservation and the obtaining of a harmless product. In order to apply this treatment it's important to monitor the diseases regarding their happening and severity to define the type of product that will be used, besides the weather conditions at the moment of application have to be considered. Treatment T10 (chemical products rotation according to the happening of diseases) allowed to obtain the highest production and gross profit (Table 2), and a most rational management of the diseases but it needs the implementation of a monitoring component of the diseases as a selection criteria of the products to apply. Treatment T3 (Th003 - T. koningiopsis) can be an alternative to contribute to the integrated management especially in crops with a high incidence of gray mold. Currently, the laboratory of biological control of Corpoica has a wet powder (WP) product made from Trichoderma koningiopsis Th003 named “Tricotec”. This bioinsecticide has demonstrated excellent results in vegetable crops for the pathogens control such as Rhizoctonia solani, getting a reduction of the disease of a 71% in Chonto tomato (Gómez et al., 2011; Gómez, 2012). It has also shown a high efficacy in the control of Botrytis cinerea and Oidium lycopersicum in tomato by being applied to the phyllosphere; nevertheless, studies on the valuation of technology indicated a high economic feasibility for the soil application and the foliar application (Gómez et al., 2011). According to Gómez (2012), in the trials made on lettuce with the bioinsecticide (WP) T. koningiopsis Th003 syptoms of the pathogen Botrytis spp. did not appear.

The best results were obtained through the following treatments: T11 (use of chemical products alternating with biological products -biocontrollers and botanic extracts-) followed by treatments T10 (chemical rotation of products according to the happening of diseases), and the treatment T3 made of Trichoderma koningiopsis (Th003); all of this considering the obtained performance/treatment, the cost of each treatment and the gross profit among others.

The treatments evaluated under experimental conditions were inefficient for the control of the downy mildew (Peronospora sp.), getting better results on the control of the gray mold and the Anthracnose of the fruit when said treatments are applied combining the opportune and adequate implementation of the cultural labors (sanitary and ventilation pruning, harvest and destruction of sick fruits, weed control, fertilization and management of pruning residues).

The products' evaluation on different grades of scaling does not allow to make the best comparison due to the possibility of having given more advantages to certain products in relation to other products that were on inferior stages of manufacture.

The low performance of the crops are explained considering that experimentally the work was carried out with only five stems per plant, and besides, the crops corresponded to the beginning of the plants' productive stage and did not reach the peak of the harvest.