GROWING TOBACCO SEEDLINGS ON DIFFERENT FLOAT NUTRIENT SOLUTIONS

Rasad virdžinijskih duhanskih hibrida DH16 i DH17 je uzgojen na tri hranidbene otopine i posađen u poljskom pokusu u Kutjevu i Virovitici 2000. i 2001. godine. Pokus je izveden po randomiziranom potpunom blok rasporedu u 4 ponavljanja i sa 4 reda po 22 biljke na pokusnoj parcelici. Srednja dva reda, bez rubnih biljaka (40 biljaka) su korištena za procjenu prinosa, cijene i vrijednosti duhanskog lista nakon berbe i sušenja. Preporučene koncentracije hranjiva u hranjivoj otopini kod nas u proizvodnji su N:P:K= 150:75:150 ppm. U pokusu su korištene koncentracije N 150 i 170, P2O5 75 i 150, te K2O 150 ppm. Analize za sva svojstva rezultirale su značajnim razlikama u okolinama (lokacija x godina), dok je za cijenu i vrijednost signifikantna bila interakcija hibrid x okolina. Obzirom na sortiment, hibrid DH17 je u prosjeku imao nešto bolja gospodarska svojstva od hibrida DH16. Izvor hranjiva u otopini, kao niti njihova koncentracija nisu značajno utjecali na istraživana svojstva duhana. Stoga rezultati upućuju na mogućnost korištenja izvora hranjiva i njihove koncentracije u hranjivoj otopini korištenoj u pokusu za uzgoj rasada hibrida duhana DH16 i DH17.Seedlings of flue cured tobacco hybrid DH16 and DH17 grown in float system on three nutrient solutions were transplanted in a field experiment at two locations in 2000 and 2001. The experiment was organized as RCBD with four replicates and four 22 plant rows per each experimental plot. Middle two rows (40 plants) were used for analyzing yield, price and value. Recommended nutrient concentration for float system in Croatia is N:P:K = 150:75:150 ppm. In the experiment concentration of N was 150 and 170, of P2O5 75 and 150, and of K2O 150 ppm. The obtained data analyses resulted in significant differences between environments (year x location) for all the traits, while hybrid x environment interaction was significant for price and value. Hybrid DH17 was on the average slightly better than DH16 in all the traits. Source of nutrients and nutrient concentration did not have significant effect on the tobacco traits. The obtained results have indicated that the fertilizers and the nutrient concentration applied in the experiment can be used in the commercial tobacco production of the hybrids DH16 and DH17

TOBACO SEED PRODUCTION IN CROATIA

U Hrvatskoj se na oko 6000 ha proizvede godišnje oko 12 000 000 kg duhana (N. tabacum L.) tipa virdžinija i berlej. U proizvodnji je preko 95% zastupljen domaći sortiment (F1 linijski hibiridi) razvijen u suradnji Agronomskog fakulteta Zagreb i Hrvatskih duhana, P.C. Kutjevo. Najzastupljeniji hibridi virdžinije u proizvodnji su DH17, DH12, DH14 i K7, a berleja BH2 i BH4. Sjemenska proizvodnja ovih hibrida izvodi se u Hrvatskim duhanima P.C. Kutjevo (kontinentalna klima, glinasto-ilovasto tlo). Roditelji u hibridima su oplemenjivačke linije dobrog prinosa i kvalitete osušenog lista, otporne na krumpirov virus Y (PVY). Proizvodnja sjemena F1 hibrida je na bazi citoplazmatsko muške sterilnosti (CMS) unešene u majčinsku liniju povratnim križanjem. Sjemenska proizvodnja obuhvaća održavanje majčinske (CMS i F analoga) i očinske linije i križanje CMS majčinske sa fertilnom očinskom linijom. Vodi se računa o odstranjivanju biljaka sa alelom za konverziju nikotina u nornikotin. Postupak proizvodnje hibridnog sjemena je nanošenje godinu dana ranije ubranog polena očinske linije čuvanog na temperaturi od -18 do -20°C na tučak majčinske CMS linije. Križanje (nanošenje polena) radi se od sredine srpnja do sredine rujna. Od oplodnje do zrelosti ploda treba oko mjesec dana. Ubrani tobolci se suše na temperaturi od 30-32°C. Očišćeno se sjeme čuva u uvjetima temperature 5-10°C i relativne vlage zraka ispod 30%. Sjeme zadrži klijavost preko 5 godina. Za uzgoj duhanskog rasada u hidroponskom sistemu koristi se pilirano sjeme koje se čuva u zatvorenim limenim posudama. U takvim posudama pilirano sjeme zadrži klijavost najmanje godinu dana. Sjeme proizvedeno opisanom tehnologijom ima visoku klijavost ( > 95%) i energiju klijanja.In Croatia on a little over 6000 ha about 12 million kg of flue-cured and burley tobacco is produced annually. Mostly domestic varieties (F1 two line hybrids) are grown. The hybrids have been developed in collaboration between Faculty of Agriculture Zagreb and Croatian Tobaccos, P.C. Kutjevo. Mostly grown flue-cured hybrids are DH17, DH12,DH14 and K7, and burley hybrids BH2 and BH4. Seed production is done in the Croatian tobaccos, P.C. Kutjevo (continental climate, loamy soil). The hybrid parents are breeding lines of high yield and cured leaf quality, resistant to Potato virus Y (PVY). The seed production is based on CMS introduced into maternal line by back crossing. It is done in two phases; maintaining parental lines, and producing F1 hybrid seed by crossing the parental lines. Care is taken of discarding nornicotine converting mutants. Pollen used for the F1 hybrid seed is stored for one year at the temperature of -18 to -20°C prior to placing on the maternal parent stigmas. Hybridization is done from middle of July to middle of September. From flower fertilization till maturity of the seeds takes about one month and seed harvesting is finished by middle of October. The harvested seed (capsules) is dryed at 28 to 32°C prior to thrashing. After thrashing the seed is stored at a temperature of 5 to 10°C and air humidity of 30%. Seed is germinable over five years. For float system seedling production seed is pelleted and packed in canes where it can stay stored for over a year. The tobacco seed produced as described above has high germinability (>95%) and uniform germination

FUELS IN TOBACCO PRODUCTION

Energy production from biomass can reduce „greenhouse effect” and contribute to solving energy security especially in the agricultural households which rely on energy from fossil fuels. In Croatia fuel-cured tobacco is produced on about 5000 ha. Gross income for the whole production is about 180 000 000 kn/year. Flue-cured tobacco is a high energy consuming crop. There are two parts of energy consumption, for mechanization used for the field production (11%) and, energy for bulk-curing (89%). In each case, presently used fuels of fossil origin need to be substituted by an alternative energy source of organic origin. Hereafter attention is paid to finding a more economic and ecologically acceptable fuel for curing tobacco. Curing flue-cured tobacco is done by heated air in curing burns. Various sources of heat have been used; wood, coal, oil and gas. In each case different burning facilities of different efficiency have been used. This has had an impact on curing costs and ecology. Recently, mostly used fuel has been natural gas. However, gas is getting expensive. Consequently, an alternative fuel for curing tobacco is sought for. According to literature, agricultural crops suitable for the latter purpose could be wheat, barley, maize, sorghum, sugar beet and some other annual and perennial plant species. Wooden pellets (by-products) are suitable for combustion too. Ligno-cellulose fuels have been used for heating since long time. However, not sufficient research has been done from an applied point of view (Venturi and Venturi, 2003). Fuel combustion is getting more efficient with developing technological innovations. The curing barn manufacturers are offering technology for combusting wooden pellets (by-products) for curing tobacco. The pellets are available on domestic market. The same technology can be used for combustion of maize grain. Within “Hrvatski duhani” research on suitability of using wooden pellets and maize grain and whole plants for curing tobacco has been undertaken. Row materials of some other farm produced ligno-cellulose annual and perennial crops are considered too, to determine the input- output gain under our production conditions