Effect of chemical desiccation application moment on germination energy of sunflower seed

Abstract

Germination energy is an important seed quality parameter, especially expressed in unfavorable ecological conditions, which delay germination and seedling emergence. Desiccation is an agro technical measure for acceleration of plant drying. This agro technical measure has many advantages such as avoiding early autumn frosts and attack of sunflower head parasites. Also, seed dispersal is reduced and there is no need for additional seed drying. Objective of this study was to assess the effect of moment of chemical desiccation application on germination energy and to determine the optimal moment for desiccation performing. Testing was conducted on sunflower inbred line HA-26-IMI-PR. Desiccation was performed with Reglone forte (Diquat), with 2 l / ha, applied at 7 day intervals, from the end of flowering to the harvest maturity. Germination energy was determined 2 and 21 months after harvest. The highest germination energy (2 months after harvest) was determined when the treatment was made 35 days after flowering (DAF), at the seed moisture of 14%. However, results showed that desiccation could be performed earlier, from the seed moisture of 40%, because at that time seed already reached high germination energy (>85%), and no significant loss was determined at testing 21 mounts after harvest. Regression analysis showed significant impact of seed moisture at the time of desiccation on germination energy. It should be noted that these results cannot be applied generally but the optimal time for performing chemical desiccation should be specifically determined for each genotype.

Energija klijanja je važan parameter kvaliteta semena, koji posebno dolazi do izražaja u nepovoljnim uslovima spoljne sredine, koji otežavaju klijanje i nicanje semena. Cilj ovog istraživanja je bio da se ispita uticaj momenta izvođenja hemijske desikacije na energiju klijanja semena suncokreta i da se utvrdi otpimalni momenat za njeno izvođenje. Ispitivanje je vršeno na inbred liniji suncokreta HA-26-IMI-PR. Desikacija je vršena preparatom Reglone forte (Dikvat) sa 2 l /ha, svakih 7 dana (DPC - dana posle cvetanja), od završetka cvetanja do žetvene zrelosti. Najviša energija klijanja je utvrđena kada je desikacija izvršena 35 dana posle cvetanja (DPC), pri vlažnosti semena oko 14%. Međutim, rezultati ukazuju da se već od vlažnosti semena oko 40% može otpočeti sa izvođenjem hemijske desikacije jer je tad već dostignuta visoka energija klijanja (>85%) koja nije značajno opala ni 21 mesec posle žetve.