Halina Kurzawińska, Stanisław Mazur

R-01a BIOCHIKOL 020 PC IN THE CONTROL OF POTATO BLIGHT Halina Kurzawińska, Stanisław Mazur Agricultural University, Department of Plant Protection ul. 29-Listopada 54, 31-425 Kraków, Poland 1. Introduction Potato late blight caused by Phytophthora infestans (Mont.) de Bary is still an economically important and the most destructive disease affecting potato crops. Recently, destruction of the potatoes is significantly higher [1, 2]. The pathogen decreases quality and quantity of potato tubers. Infected potato tubers stop develop and seemingly healthy tubers may rot later when in store. According to Fry [3] as much as 100% of the yield may be lost on non protected plantations and this fact is associated with early epidemic of the disease. According to Kapsa [4] the obstacle in wide use of chemical methods against potato blight are costs connected with performance some or dozen chemical spraying necessary for complete protection. Increase of environmental contamination by pesticides incline us for searching new ones, alternative control methods of the pathogen. The literature provides information about possibility of using chitosan in the protection of plants against different diseases [5-10]. Biochikol 020 PC (2% of chitosan), can show an anti-viral, anti-bacterial and anti-fungal effect and it belongs to the inducers of plants resistance [11-16]. The objective of our study was to assess the effect of dressing and spraying plants with Biochikol 020 PC on the infestation of potato leaves and tubers cv. Ibis by P. infestans. 2. Materials and methods The field experiment was conducted in the years 2005-2006 at the Experimental Station in Mydlniki near Kraków owned by the Academy of Agriculture, on brown soil. Winter wheat was forecrop. Potatoes of mid-early cv. Ibis susceptible to leaf infection and mid-resistant to tubers infection were cultivated. The experiment was established in the third decade of April (space out 62.5 cm) with the Polish Chitin Society, Monograph XII, 2007 179

H. Kurzawińska, S. Mazur method of random squares in four replications. 100 tubers were planted on each experimental plot. Cultivation and fertilization of the soil were done according recommendation of proper agrotechny. In the present study the effect of Biochikol 020 PC in concentration 2.5%, used for dressing potato tubers and spraying of plants during vegetation period was noted down. Vitavax 2000 FS (20% carboksyn + 20% tiuram) was used as the standard. Four different combinations of potato late blight control were used: 1. Control plants derived from no dressed tubers; 2. Plants derived from tubers dressed with Biochikol 020 PC; 3. Dressing tubers + 4 times spraying plants with Biochikol 020 PC at concentration of 2,5%; 4. Plants derived from tubers dressed with Vitavax 2000 FS in dose 5 ml/kg tubers. The chemical sprayings were conducted with use of sprayer Kaskada (1000 l liquid on 1 ha). First treatment was done when visible disease symptoms occurred on leaves. The preparation was applied as plant spraying from 10-14 days in relation to weather conditions (4 times in each vegetation period). Disease severity was rated by visual assessment based on a 1-9 scale, where 1 - means no visible disease symptoms or few scattered necrotic spots, 9 - very strong lesions, foliage completely destroyed [17]. 25 random plants were rated individually from each experimental plot. First analysis was down after occurring first symptoms of disease. Scores were taken in July (10, 20, 29) and in August (8, 18, 28) 2005 year. In the next year in July (5, 16, 26) and in August (6, 16, 28). Crop yield was determined during harvest. The results were calculated in percents for the comparison between the protected plants and no treated control where yield take of 100. The intensity of infection of potato tubers through P. infestans was assessed directly after harvest. The percent of infested tubers in sample was noted down (100 tubers from each plot). The results (mean disease index and tuber infestation by P. infestans) were treated statistically using the analysis of variance followed by Duncan s test (α = 0,05). 3. Results and discussion Meteorological conditions in the south region of Poland in both two years (2005 and 2006) were different as well as disease appearance. In 2005, potato blight appeared on potato plants 9th and in 2006 5th. Based on analysis throughout the experimental period mean disease index of leaves infestation during first four observations has the same level both in control plots and where Biochikol 020 PC and fungicide Vitavax 2000 FS were used (Table 1). However, growth dynamics of potato blight was weaker, compared with the control objects. On the base of data from last analysis of leaves infection it s evident that use of Vitavax 2000 FS and Biochikol 020 PC for tuber dressing and plant spraying during vegetation period in 2005-2006 had significant effect on limitation incidence of potato blight. Mean disease index from this combinations was significantly lower compared, with the control and ranged from 4.7 to 8.0 (Table 1). 180 Polish Chitin Society, Monograph XII, 2007

Biochikol 020 PC in the control of potato blight Table 1. The influence of tested preparations on potato leaves infestation through Phytophthora infestans (2005-2006); *Note: means followed by the same letter do not differ at 5% level of significance (Duncan's multiple range test). Combination 1. decade mean index of infestation/following analysis 2. decade 3. decade 1. decade 2. decade 3. decade 2005 2006 2005 2006 2005 2006 2005 2006 2005 2006 2005 2006 Control 1.6 a* 1.3 a 1.9 a 2.3 ab 2.5 a 3.0 c 5.4 a 3.7 c 7.9 a 4.6 c 9.0 b 6.2 b Tubers dressed with Biochikol 020 PC 1.5 a 1.2 a 1.8 a 2.2 a 2.4 a 2.6 a 5.4 a 3.2 ab 7.8 a 3.8 b 8.0 a 4.7 a Tubers dressed and sprayed plants with Biochikol 020 PC 1.4 a 1.3 a 1.6 a 2.2 a 2.3 a 2.5 a 5.3 a 3.2 a 7.7 a 3.6 a 7.9 a 4.7 a Tubers dressed with Vitavax 2000 FS 1.3 a 1.3 a 1.8 a 2.4 b 2.3 a 2.7 b 5.4 a 3.4 b 7.8 a 3.8 b 7.9 a 4.7 a Table 2. The influence of tested preparations on yield increase (in comparison with control) and health status of potato tubers; *Note see table 2. Combination yield increase, % 2005 2006 % of infected tubers yield increase, % % of infected tubers Control 100.0 4.50 a * 100.0 3.00 b Tubers dressed with Biochikol 020 PC 137.8 2.50 a 114.3 2.30 a Tubers dressed and sprayed plants with Biochikol 020 PC 210.1 1.80 a 236.3 1.70 a Tubers dressed with Vitavax 2000 FS 122.3 2.30 a 185.7 2.10 a Tuber yield from protected plots was higher, compared with the control. The highest increase of yield, was obtained with tuber dressing and plant spray with Biochikol 020 PC (Table 2). On nontreated plants the reduction of 50-70% assimilation area of leaf strongly limited the yield. Earlier infection resulted higher infection of plants [18]. According to Kapsa [1] premature infestation of leaves resulted in decreasing tuber yield up to 50%. Infestation of tubers through P. infestans was lower in combinations where plant protection was done, compared with the control. In the first year of investigations (2005) those differences were statistically no different but in the next year 2006 applied preparations significantly reduced development of potato blight on tubers tested cultivar (Table 2). According to Kapsa [4] chemical protection of potatoes had big influence on the yield and quality of commercial tubers. Several studies have demonstrated big effectiveness of chitosan in protection of vegetable crops [5, 6, 8, 11, 14]. Biochikol 020 PC applied as tubers and bulb dressing or spraying plants provided protection against different species of Phytophthora, and Fusarium oxysporum, rose against Sphaerotheca pannosa var. rosae, Peronospora sparsa and Botrytis cinerea [7, 10]. According to Kuć [18] activites of genes, which starting form biochemical components showed fungicidal and fungistatic effects. Obtained results from the two-year experiments indicate on possibility of use Biochikol 020 PC for protection of potatoes against potato blight. It has particular importance in ecological Polish Chitin Society, Monograph XII, 2007 181

H. Kurzawińska, S. Mazur methods of potato production where this disease has swell meaning and where chemical protection is forbidden. Use of biological product which inhibits growth of many plant pathogens has more meaning, especially in aspect of limiting of traditional chemical treatment. Effectiveness of chitosan was compared with chemical treatment. Results of conducted experiments showed ability to use chitosan to limit fungal, bacterial and viral diseases [6, 12, 13, 15, 15]. 4. Conclusions Based on an analysis throughout the experimental period, it was found that the application of Biochikol 020 PC and standard preparation resulted in the decrease of potato blight spread. The tuber yield from protected plots was higher, compared with the control. The highest increase of the yield was noted down in combination with Biochikol 020 PC used for tuber dressing and spraying plants. The tested product decreased the number of infested tubers by P. infestans. 5. References 1. Kapsa J., 2001: Zaraza [Phytophthora infestans (Mont.) de Bary] występująca na łodygach ziemniaka. Monografie i Rozprawy Naukowe IHAR, Radzików, nr 11. 2. Kurzawińska H., Gajda I., 2004: Ocena przydatności niektórych fungicydów w ochronie ziemniaka przed zarazą Phytophthora infestans (Mont.) de Bary. Biul. IHAR, 233, 333-338. 3. Fry W.E., 1994: Role of early and late blight suppression in potato pest management. p. 166-177. In Advances in Potato Pest Biology and Management (Zehneder G.W., Powelson M.L., Jansson R.K., Raman K.V., eds.). The American Phytopathology Society, St. Paul, Minnesota, USA. 4. Kapsa J., 2000: Wykorzystanie nowych elementów ochrony upraw ziemniaka przed zarazą. Progress in Plant Protection/Postępy w Ochronie Roślin, vol. 40(1), 169-176. 5. Lafontaine P.J., Benhamou N., 1996: Chitosan treatment an emerging strategy for enhancig resistance of greenhouse tomato plants to infection by Fusarium oxysporum f.sp radicis-lycopersici. Biocontrol Science and Technology 6(1), 1996, 111-124. 6. Mazur S., Szczeponek A., Nawrocki J., 2003: Effectiveness of chitosan applications in the control of some pathogens on cultivated plants. Progress on Chemistry and Application of Chitin and its Derivatives, vol. IX, 93-100. 7. Orlikowski L.B., Skrzypczak Cz., 2003: Biocides in the control of soil-borne and leaf pathogens. Hortic. Veget. Grow., 22 (3), 426-433. 8. Pięta D., Pastucha A., 2002: Efektywność ochronnego działania chitozanu w ograniczaniu chorób grzybowych soi. Acta Scientiarum Polonorum ser., Hortorum Cultus, 1(1), 31-43. 9. Pośpieszny H., 1997: Niektóre aspekty stosowania chitozanu w ochronie roślin. Progress in Plant Protection/Postępy w Ochronie Roślin, 306-309. 10. Wojdyła A.T., 2001: Chitosan in the control of rose diseases 6 year trials. Bull. Pol.Ac. Sci., Biol. Sci. 49 (3), 243-252. 11. Benhamou N., Lafontaine P.J., Nicole M., 1994: Induction of systemic resistance to Fusarium crown and root rot in tomato plants by seed treatment with chitosan. Phytopathology, 84, (12), 1432-1444. 12. Orlikowski L.B., Skrzypczak Cz., Wojdyła A., Jaworska-Marosz A., 2002: Wyciągi roślinne i mikroorganizmy w ochronie roślin przed chorobami. Zesz. Nauk. AR Kraków 387 (82), 19-32. 13. Patkowska E., Pięta D., 2004: Introductory studies on the use of biopreparations and organic compounds for seed dressing of runner bean (Phaseolus coccineus L.). Folia Univ. Agric. Stetin., Agricultura 239 (95), 295-300. 182 Polish Chitin Society, Monograph XII, 2007

Biochikol 020 PC in the control of potato blight 14. Pięta D., Patkowska E., Pastucha A., 2006: Influence of Biochikol 020 PC used as seed dressing of bean on healthiness and yield of plants. Progress on Chemistry and Application of Chitin and its Derivatives, Vol. XI, 159-170. 15. Pośpieszny H., 1995: Inhibition of tobacco mosaic virus (TMV) infection by chitosan. Phytopath. Polonica, 10 (XXII), 69-74. 16. Pośpieszny H., Żołobowska L., Maćkowiak A., Struszczyk H., 1995: Antibacterial activity of chitin derivatives. In: Biological control of soil-borne and post-harvest pathogens, ed. Orlikowski L.B., Skrzypczak Cz., Skierniewice, 99-102. 17. Metodyka obserwacji i pobierania prób w agrotechnicznych doświadczeniach z ziemniakami. Red. S. Roztropowicz, Instytut Ziemniaka, Bonin, 1985, 12-15. 18. Van der Plank J.E., 1963: Plant disease: Epidemics and control. Academic Press, New York. 19. Kuć J., 1987: Plant immunization and its applicabillity for disease control. Innovative Apptoaches to Plant Disease, 255-274. Acknowledgment Supported by the Ministry of Science and Higher Education No. 2P06R 00129. Polish Chitin Society, Monograph XII, 2007 183