| Abstract | Temperatura i vlaga dva su najvažnija parametra koja utječu na klijanje korovne vrste sivog muhara (Setaria glauca). Cilj ovog istraživanja bio je utvrditi biološki minimum (Tb) i biološki vodni potencijal (Ψb), potrebni za klijanje sivog muhara. Za potrebe ovog istraživanja sjeme vrste Setaria glauca prikupljeno je na lokaciji Šašinovečki Lug u jesen 2017. Početkom ožujka 2018. godine postavljen je pokus utvrđivanja klijavosti sivog muhara u DAFNAE laboratoriju Sveučilišta u Padovi. Za utvrđivanje biološkog minimuma sjeme ove vrste posijano je u Petrijeve zdjelice te je stavljeno u klima komoru s fotoperiodom od 12 h dan i 12 h noć istovremeno na šest konstantnih temperatura: 4 ˚C, 8 ˚C, 12 ˚C, 16 ˚C, 20 ˚C i 24 ˚C. U svrhu simulacije vodnog stresa u tlu korišteno je sedam različitih koncentracija otopina polietilen glikola (PEG): -0,05, -0,10, -0,25, -0,38, -0,50, -0,80, -1,00 MPa i kontrolni tretman (0,00 MPa) prekriven samo destiliranom vodom. Sjeme sivog muhara posijano je u plastične posude i postavljeno u klima komoru pri konstantnoj temperaturi od 24 °C i s fotoperiodom od 12 h dan i 12 h noć. Rezultati istraživanja ukazuju kako povećanjem temperature s 4 °C na 24 °C raste prosječna klijavost vrste Setaria glauca. Povećanjem temperature smanjuje se broj dana (d) potrebnih za ponik 10 %, 50 % i 90 % posijanih sjemenki. Utvrđivanjem dinamike klijanja pri različitim temperaturnim režimima ustanovljeno je da biološki minimum sivog muhara za područje Šašinovečkog Luga iznosi 6,6 °C. Klijavost muhara se također razlikovala i pri različitim koncentracijama polietilen glikola. Najveća prosječna klijavost utvrđena je pri koncentraciji od -0,25 MPa, dok je na koncentracijama od 0,00 MPa, -0,05 MPa i -0,10 MPa utvrđena manja ukupna klijavost (60, 63,3 i 62,8 %). Praćenjem dinamike klijanja sivog muhara utvrđeno je da se vrijeme potrebno za ponik 50 % sjemenki povećava s povećanjem zasićenosti polietilen glikolne otopine. Najkraći vremenski period potreban za ponik 50 % sjemenki utvrđen je na kontrolnom tretmanu (3,5 d) dok je najdulji broj dana potreban za ponik 50 % sjemenki utvrđen na koncentraciji od -0,50 MPa (17,9 d). Utvrđen biološki vodni potencijal za vrstu Setaria glauca za područje Šašinovečkog Luga iznosi -0,71 MPa. Utvrđena je statistički značajna razlika između biološkog minimuma „hrvatskog“ ekotipa u odnosu na „talijanski“ ekotip sivog muhara, dok nije utvrđena razlika u biološko vodnom potencijalu. |
| Abstract (english) | Temperature and moisture are two most important parameters that are affecting emergence of the weed species yellow foxtail (Setaria glauca). The aim of this study was to estimate base temperature (Tb) and base water potential (Ψb), the parameters that are necessary for emergence of yellow foxtail. The seeds of the species Setaria glauca was collected on location Šašinovečki Lug in the autumn of 2017. The estimation emergence experiment was conducted at the beginning of March 2018 in the DAFNAE laboratory at the University of Padova. For the purpose of estimation of base temperature the seeds were seeded in the Petri dish and put in the climatic chambers with photoperiod of 12 h day and 12 h night on six constant temperatures: 4 ˚C, 8 ˚C, 12 ˚C, 16 ˚C, 20 ˚C and 24 ˚C. For the purpose of simulating water stress in the soil seven different concentrations of polyethylene glycol (PEG) solutions were used: -0,05, -0,10, -0,25, -0,38, -0,50, -0,80, -1,00 MPa and a control (0,00 MPa) covered only with distilled water. The yellow foxtail seeds were planted in plastic containers and placed in a climatic chamber at a constant temperature of 24 °C with a photoperiod of 12 h day and 12 h night. The results of the study indicate that with increasing temperatures from 4 °C to 24 °C the average emergence of species Setaria glauca is increasing too. With increasing temperatures, the time needed for 10 %, 50 % and 90 % seeds to emerge was shortened. By monitoring the germination dynamic of yellow foxtail on different temperature regimes, the base temperature was estimated to be 6,6 °C. The emergence of yellow foxtail was also different on different concentrations of polyethylene glycol. The highest total average germination was estimated on contcetration of -0,25 MPa, while on concentrations of 0,00 MPa, -0,05 MPa and -0,10 MPa total average germination decreased (60, 63,3 i 62,8 %). By monitoring germination dynamics of yellow foxtail it was estimated that the time necessary for 50 % seeds to germinate is increasing with increasing concentration of polyetylene glycol solution. The shortest time period required for 50 % seeds to germinate was estimated on control treatment (3,5 d) while the largest number of days required for 50 % seeds to germinate was estimated on concentration of -0,50 MPa (17,9 d). The base water potential for weed species Setaria glauca in continental part of Croatia was determined to be -0,71 MPa. There was a statistically significant difference in base temperature of the “Croatian” ecotype compare to the “Italian” ecotype of yellow foxtail, while there was no difference in base water potential. |
