Title: Use of three doses of VIUSID AGRO in tobacco (Nicotiana tabacum L.) cultivation

Transcription

1 UNIVERSIDAD DE SANCTI SPÍRITUS José Martí Pérez Faculty of Agricultural Sciences Agronomy Department Title: Use of three doses of VIUSID AGRO in tobacco (Nicotiana tabacum L.) cultivation MSc. Jorge F Meléndrez Rodríguez

2 Introduction Tobacco (Nicotiana tabacum L.), a plant native to South America, is annually cultivated and sown in many parts of the world (Shew and Lucas, 1991). In Cuba, it requires priority attention, not only to attain high profits, but also to maintain the exquisite quality and fame that has set it apart the world over for 400 years, and because it represents one of the most important sources of revenue in foreign currency for the country (Espino, 1996). According to Espino and Torrecilla (1999), three types of black tobacco are cultivated in Cuban tobacco areas, which occupy 88.3% of the national area, and as of the harvest of 1999, 13 provinces and 109 municipalities participate in cultivation, which backs up this activity as a large source of growing employment. Included in the most cultivated varieties in the central and eastern regions, where the Espiritu province is found, are: Habana 92 and Sancti Spiritus 96 (SS-96), especially for the sun grown dark tobacco, with more than ha. Obtaining quality harvests is an element that depends on many factors, including the plant's nutrition, its growth and its development, which play a determining role. For this reason, using chemical fertilisers has been an inviolable practise in cultivation. Using chemical fertilisers in agriculture brings collateral problems, such as environmental contamination and detriments to human health. Additionally, with a world-wide increase in demands regarding security and cleanliness measures in productions, interest in finding environmentally-friendly alternatives has increased. In this sense, products based on bacteria that promote vegetable growth (PGPB) have been used with discrete results. Notwithstanding, using microorganisms both for biological control and for promoting vegetable growth requires long periods of time to demonstrate their action. Many times, they lose their biological activity and create a negative impact by releasing microorganisms into the environment, thereby creating an ecological imbalance. Recently, FitoMas E, a product derived from sugarcane processing, has been used. This product was applied in the field as a promoter of vegetable growth with several cultivations, such as beans, and in biotechnological techniques for in vitro cultivation. At the beginning of the 20 th century, Japanese scientists discovered a chemical compound extracted from the mushroom Gibberella fujikuroi, which stimulated seedling growth. Later on, it was found that this compound, which was also found in higher plant forms, corresponded to gibberellins. As of today, 90 gibberellins have been isolated and identified from higher plant forms, fungi and even bacteria. Their metabolism is fairly well-known, mainly thanks to dwarf mutants with lesions in the genes that encode enzymes from the biosynthetic route

3 and inhibitors of these enzymes' action (Takahasi et al., 1991). The gibberellins are classified within plant hormones and are synthesised in the apical primordium of leaves, seeds and roots, moving in two directions within the vegetable. There are several groups of gibberellins. Amongst them, the most wellknown in agriculture is Ascophyllum nodosum (AG3). They have different functions within the plant, including stimulating blooming, promoting fruit development and seed germination, given that they interrupt the latent period and mobilise reserves, inducing bud sprouting, delaying fruit maturation, increasing stalk growth, and other effects. Research carried out on VIUSID AGRO in other countries has proven the product's efficacy in increasing productivity. In this sense, in Honduras (Coello 2010) it was applied to several different cultivations with different doses, showing hopeful results, just as occurred in Spain with cultivations such as aubergine, strawberry, watermelon and grape. Domínguez (2005) states that as of today, there are only agronomical studies carried out in Honduras by Coello and Huetes, where experiments have been performed on cucumber, corn, sweet potatoes, artichoke, rose, mango, watermelon, signal grass and fodder, all of which obtained positive results in using VIUSID AGRO through molecular activation. Within the sustainable agriculture strategy, the development of alternatives to excessive use of chemical products is being considered more and more. For this reason, it is necessary to study the effect of VIUSID AGRO on tobacco cultivation's morpho-agronomic parameters. Scientific problem: No application dose for VIUSID AGRO in tobacco (Nicotiana tabacum L.) cultivation is known. Hypothesis: If three different doses of VIUSID AGRO are used in tobacco (Nicotiana tabacum L.) cultivation, then the one with best behaviour in regards to tobacco cultivation's morpho-agronomic parameters may be determined. General objective To determine the dose with best behaviour regarding tobacco (Nicotiana tabacum L.) cultivation's morpho-agronomic parameters. Specific objectives To compare three different doses of VIUSID AGRO in tobacco (Nicotiana tabacum L.) cultivation. To evaluate the effect of VIUSID AGRO on tobacco (Nicotiana tabacum L.) cultivation's morpho-agronomic parameters.

4 MATERIALS AND METHODS Experiment location This task was carried out at a private producer's farm with more than 70 years of experience in tobacco cultivation, belonging to the CCSF: El Vaquerito, in the Taguasco municipality (located to the north of the town Zaza del Medio and adjoining farms belonging to other producers from said entity). The experiment was performed during the campaign, on siliceous brown soil, as per Hernández et al (1999), using the Habana-92 tobacco variety, which was transplanted on the 2 December, Tasks performed The soil was prepared traditionally by tilling, harrowing and ploughing successively. Fertilisation was carried out as indicated in the Guide for Tobacco Cultivation MINAGRI (2012). The stem was covered between 8 and 10 days after transplanting, acting as a control for undesirable plants. Next, the soil was earthed up between days 20 and 22. Irrigation guaranteed moisture to the planting, reaching a total of three with a 15-day interval. The apical bud was eliminated between 40 and 48 days of age after planting, as per the producer's criteria and experience. From a plant protection perspective, the insecticides shown in table 1 were applied. Table 1. Plant protection treatments INSECTICIDE NUMBER OF APPLICATIONS DOSE PLAGUE CONTROLLED Cypermethrin + methyl parathion Duple B Mixture ( ) 2 20 kg CP/ha Heliothis virescens Acephate (Acephan PS 75) 1 1 kg/ha Heliothis virescens Spatial arrangement of treatments The experiment was set up under production conditions, taking four experimental swathes, each one of them corresponding to each treatment to be evaluated. These swathes were composed of five furrows of 90 plants each, evaluations being

5 made in the central furrow, randomly selecting 15 plants per treatment, taking five plants at the beginning part of the furrow, five plants in the middle part, and five plants at the end part. The first ten and the last ten plants were discarded. Treatments evaluated For the experiment, experimental parcels were used for each treatment, with a total number of plants per treatment of 450, using a 0.80 m x 0.30 m planting frame. The evaluated treatments are shown in table 2. Table 2. Treatments evaluated TREATMENTS DOSE A: VIUSID AGRO 0.5 ml/5 L of water B: VIUSID AGRO 1,5 ml/5 L of water C: VIUSID AGRO D: Control 1 ml/5 L of water Untreated The treatment applications to be evaluated were carried out seven days after the transplant, using a manual Matabi sprinkler with a 16 litre capacity, at weekly intervals, as per manufacturer recommendations. The total number of treatment applications was five, suspending applications on the 13 December, 2012, under producer recommendation. Evaluations performed Two evaluations were performed during the cultivation cycle: the first, 43 days after transplantation, and the second, when the planting was 68 days old (coinciding with the time of cutting). In both cases, the plant's height was measured, the total number of leaves, the stalk's diameter and the length and width of the two central leaves.

6 Statistical processing In processing data, the Windows SPSS statistical package was used. Applying the Kolmogorov-Smirnov normality test, the variance homogeneity test was carried out, from whence the evaluations that showed homogeneity underwent an Anova and the Duncan test with a 0.05 significance level. For the evaluations not showing homogeneity, the non-parametric Kruskal-Wallis test was applied, and those that showed significant differences underwent the Mann-Whitney test to determine between which treatments significant differences existed. RESULTS AND DISCUSSION Analysis of the first evaluation If we observe table 3, where the statistical analysis corresponding to the first measurements taken appears, the result is that treatment B exhibits the best behaviour in all parameters evaluated, with significant statistical differences in comparison with the other treatments. We attribute these results to using a greater dose of VIUSID AGRO than the other treatments, which creates a marked effect on the evaluated parameters. On the other hand, when we analyse the behaviour of the plant's height, the diameter of the stalk and the length and width of the central leaves, treatments B and C exhibit better behaviour. They do not statistically differ from one another, with significant differences in comparison with treatments A and D, which do differ from each other. Table 3. Statistical analysis of the first evaluation Treatments Plant height (m) Diameter of the stalk (m) Total leaves Length of the two central leaves (m) Width of the two central leaves (m) A. 1 ml/5 L 0.51 b b b 0.40 b 0.23 b B. 1.5 ml/5 L 0.66 a C. 0.5 ml/5 L 0.60 a a a a 0.44 a 0.25 a b 0.42 a 0.26 a D. Control 0.40 c c c 0.33 c 0.20 c Legend: Different letters differ for a 0.05 level. The values correspond to the average.

7 In the case of total leaves, treatment B statistically differs from the rest of the treatments; A and C do not differ from each other, but they do differ from treatment D. Treatments A, B and C, for all evaluated parameters, surpass the untreated control, which constitutes a production control and was attended to with all of the tasks described in the work methodology. This allows us to affirm that using VIUSID AGRO at different doses causes a stimulating effect in the plant's growth, which contributes to improving the cultivation's morpho-agronomic parameters, an effect which is reinforced with the 1.5 ml dose of VIUSID AGRO in five litres of water. These results corroborate Coello (2010) and Domínguez's (2005) statement, who upon using VIUSID AGRO at different doses attained better behaviour in fruit and vegetable cultivation. The results obtained here do not coincide with those obtained by Cabrera (2013), who in this very cultivation, in the second harvest, obtained the best results when he used the smaller dose of VIUSID AGRO, attributing the behaviour to previous applications of the formula. Analysis of the second evaluation When we observe table 4, showing the statistical results corresponding to the second evaluation carried out, the result we obtain regarding plant height is that treatment C, which shows statistical differences in comparison with the rest of the treatments, exhibits the best behaviour. Coello (2010), using this very dose on Cynara scolymus L. (artichoke) obtained good results, but they were greater when he tried larger doses, reaching double internode growth. This means that as far as this parameter is concerned, our results do not coincide with this author. Table 4. Plant height behaviour Treatments Plant height (m) A. VIUSID AGRO 1 ml/5 L 0.96 bc B. VIUSID AGRO 1.5 ml/5 L 0.97 b C. VIUSID AGRO 0.5 ml/5 L 1.08 a D. Control 0.88 c Legend: Different letters differ for a 0.05 level. The values correspond to the average. As far as the other treatments are concerned, there are no differences between A and B or between A and D; treatments B and D statistically differ from each other. Treatment D, which is a production control, exhibits the worst results. This demonstrates that using VIUSID AGRO, regardless of the dose used, exhibits a behaviour that justifies its use. Authors such as Cabrera (2013) and Maceda (2013)

8 obtained good results in this very cultivation, using 0.5 ml and 1 ml/ doses of VIUSID AGRO per five litres of water, respectively. On table 5, we observe how, regarding stalk diameter, B exhibits the best behaviour with significant differences in comparison with the other treatments. On the other hand, A and C do not differ from each other. Treatment A's behaviour is similar to the control. This allows us to consider that the dose is insufficient to attain the desired effect on tobacco cultivation. Table 5. Stalk diameter behaviour Treatments Stalk diameter (m) A. VIUSID AGRO 1 ml/5 L bc B. VIUSID AGRO 1.5 ml/5 L a C. VIUSID AGRO 0.5 ml/5 L b D. Control c Legend: Different letters differ for a 0.05 level. The values correspond to the average. These results coincide with those obtained by Coello (2010), who, in using VIUSID AGRO at 1.5 ml/5 L, managed to increase the artichoke's internode growth to double, compared with the 0.5 ml/5 L dose, and when using an even greater dose of 2 ml/5 L, he once again managed to duplicate the growth of the cultivation's internodes. Other authors such as Expósito (2013) and Pérez (2013) achieved the best results with a 1.5 ml/5 L dose in tomato and onion cultivations, respectively. On the other hand, we do not coincide with the results obtained by Cabrera (2013), who, in cultivating tobacco in its second harvest, obtained the best results with the lesser dose of VIUSID AGRO. In the case of the total number of leaves, as shown on table 6, there is little statistical differentiation between the evaluated treatments. Table 6. Total leaf behaviour Treatments Total leaves A. VIUSID AGRO 1 ml/5 L 16.4 a B. VIUSID AGRO 1.5 ml/5 L 17.3 a C. VIUSID AGRO 0.5 ml/5 L 17.7 a D. Control 15.0 b Legend: Different letters differ for a 0.05 level. The values correspond to the average. The treatments with the three doses of VIUSID AGRO have similar statistical behaviour, significantly differing from the control. The total number of leaves during

9 the stage when this evaluation was carried out is a parameter not highly influenced by the study's treatments, in that it influences the apical bud elimination task under the producer's criteria, who, to this end, takes the cultivation's foliar development into account. In the same fashion as the previous parameters, using VIUSID AGRO contributes to obtaining favourable results. As such, we coincide with authors such as Coello (2010), Cabrera (2013), Pérez (2013) and Maceda (2013), who promoted development in the cultivations with which they worked with VIUSID AGRO. As far as the length and width of the leaves are concerned, we observe on the table that they have similar behaviour. The best results are from treatments with the 0.5 ml/5l and 1.5 ml/5 L doses. The latter significantly differs from A and D. Treatments A and B statistically behave the same, B differing from the control. Treatments A and D exhibit no significant differences. Table 7. Central leaf length and width behaviour Treatments Leaf length (m) Leaf width (m) A. VIUSID AGRO 1 ml/5 L 0.49 bc 0.27 bc B. VIUSID AGRO 1.5 ml/5 L 0.52 ab 0.29 ab C. VIUSID AGRO 0.5 ml/5 L 0.54 a 0.30 a D. Control 0.46 c 0.25 c Legend: Different letters differ for a 0.05 level. The values correspond to the average. Generally speaking, this evaluation shows that the treatments with doses of VIUSID AGRO have a stimulating effect on tobacco cultivation's morpho-agronomic parameters, an effect which is accented when the greater dose is used. In this experiment, VIUSID AGRO was no longer applied during the last month of planting due to a suggestion made by the producer, who deemed that a considerable growth effect on the plants was perceived. These results corroborate those obtained by Domínguez (2005), Coello (2010), Maceda (2013), Expósito (2013), Cabrera (2013) and Pérez (2013), who found that, in using VIUSID AGRO, there was a considerable increase in growth for the cultivations with which they were working. This issue is accentuated by VIUSID AGRO's unique characteristics from having all of its components undergo molecular activation. This is described by Catalysis (2012), who posits that molecular activation consists of subjecting molecules to a determined electrical field under specific physical-chemical constants, thereby increasing their biological and therapeutic properties in low concentrations. This very author also shows that not all molecules are susceptible to activation and that this process, considerably improving biological activity of the molecules, does not alter their chemical structure.

10 Conclusions The three doses of VIUSID AGRO improved the tobacco planting s morphoagronomic parameters. The dose with the best effect on tobacco cultivation was 1.5 ml per five litres of water. Recommendations Use VIUSID AGRO with the proportion of 1.5 ml per five litres of water on tobacco plantings, with weekly applications, until the final cultivation stage. In following experiments, evaluate the curing, storing and benefit phases of tobacco.