Experimental evaluation of organic substrates for germination testing of soybean seed

Abstract

High germination of seeds and seedling establishment are critical for soybean production since it determines crop density and eventually affects the yield. Accurate evaluation of the ger mination potential of sowing material is valuable, as well as initial quality assessment of newly harvested seed. ISTA Rules prescribe alternative methods for soybean seed germination: sand, between paper, top of paper covered with sand and since 2020 organic growing media. In the Seed Testing Laboratory at the Maize Research Institute soybean germination is conducted in the sand at 20<=>30°C. The objective of this study was to evaluate several available organic growing media and compare results obtained with the standard laboratory method. Five soybean seed lots of different quality were tested in four germination growing media (3 organic and sand), at two temperature regimes (25 °C and 20<=>30°C). Statistical analyses showed that all types of organic growing media were of the same quality. Slightly higher germination in organic growing media was obtained in the experiment at 20<=>30°C compared to sand, but those differences were not statistically significant. When testing was done in germinator with 25°C positive effects of organic growing media were identified and this impact was significant, especially for low-quality seed lots. The experimental outcome was to continue with routine practice and use organic growing media for retesting of seed lots with lower germination as an alternative substrate. Key words: germination, organic substrate, sand, soybean, temperature

Visoka klijavost semena i uniforman rast klijanaca su presudni za proizvodnju soje, jer od toga zavisi gustina useva i na kraju, prinos. Precizna procena potencijala klijavosti setvenog ma terijala je izuzetno važna, kao i početna procena kvaliteta tek požnjevenog semena. Međunarod na pravila za ispitivanje semena propisuju alternativne metode za klijanje semena soje: pesak, između filter papira, na filter papiru uz prekrivanje peskom, i od 2020. godine organski supstrat. U Laboratoriji za ispitivanje semena, Instituta za kukuruz “Zemun Polje”, naklijavanje soje se vrši u pesku, na temperaturi 20<=>30°C. Cilj ove studije bio je proceniti nekoliko dostupnih organskih supstrata i uporediti dobijene rezultate sa dosadašnjom laboratorijskom metodom. Pet partija soje različitog kvaliteta testirano je u četiri podloge za naklijavanje (3 organske i pe sak), pri dva temperaturna režima (25°C i 20<=>30°C). Statistička analiza pokazala je da su sve organske podloge istog kvaliteta. Nešto veća klijavost u organskom supstratu u poređenju sa pes kom je ostvarena u eksperimentu na 20<=>30°C, ali te razlike nisu bile statistički značajne. Pri likom ispitivanja u klijalištu sa 25°C pokazali su se pozitivni efekti organske podloge i ovaj uticaj je bio značajan, posebno za partije slabijeg kvaliteta. Nakon analize eksperimentalnih rezultata odlučeno je da se nastavi sa dosadašnjom laboratorijskom praksom naklijavanja u pesku i da se organska podloga koristi kao alternativni supstrat za ponovno ispitivanje partija semena sa nižim procentom klijavosti.