The objective of this study was to investigate the influence of seed coat colour on the seed quality of four red clover cultivars (germination, dormancy (hard seeds), dead seeds and initial seedling growth (vigour)) produced in Serbia over a period of two years. The seeds analyzed were first separated visually into bright, dark and mixed seed groups, followed by subsequent digital colour measurements. The results obtained showed that the seed coat colour of red clover could be considered a good indicator of seed quality and seedling growth ability. The results furthermore showed that bright-coloured seeds of red clover cultivars indicated increased vigour and seed quality compared to other colours. The impact of the production area and year on the seed quality parameters was inconclusive. A high variability in hard (CV = 22.22 %) and dead seeds (CV = 40.18 %) was recorded between different seed lots of red clover. A lower variability was found in the germination parameter of bright- and mixed-coloured seeds (CV = 4.53 % and CV = 8.53 %). The seed coat colour could be an important factor in determining the quality of red clover seeds, potentially increasing germination simply by removing dark-coloured seeds.

Seed treatments with zinc, boron, biostimulant Coveron and MIX (zinc + boron + Coveron) were applied to three lettuce and three celeriac cultivars. Seeds of three wheat cultivars were treated under laboratory conditions with Trichoderma harzianum and eight Bacillus spp. Seed germination, seedling growth, and the presence of the following pathogens were determined: Fusarium sp., Alternaria sp., Penicillium sp., and Mucor sp. The Coveron treatment was the most effective on lettuce seeds tested in the germination cabinet. Seed germination was higher by 4% than in the control. Alternatively, germination of seeds treated with boron in the greenhouse was higher by 12% than in the control. The Coveron treatment had the highest effect on the shoot length, which was greater by 0.7 and 2.1 cm in the germination cabinet and the greenhouse, respectively. This treatment was also the most effective on the root length. Zn, B, and MIX treatments increased celeriac seed germination by 14% in the germination cabinet. The Zn treatment was the most efficient on seeds tested in the greenhouse. The germination was higher by 15%. A significant cultivar × treatment interaction was determined in both observed species under both conditions. The maximum effect on wheat seed germination (8%) was achieved with the T. harzianum treatment in the Salazar cultivar. A significant interdependence (p ≤ 0.01 to p ≤ 0.001) was established between seed germination and the seedling growth. The interrelationship between seed germination and pathogens of all cultivars was negative.

The purpose of this paper is to evaluate the effect of the year of cultivation, seed population and mycorrhizal seed treatment on two most important indicators of the pepper seed quality, namely germination energy and total germination. The pepper seed quality parameters, i.e. the first count and the total germination rate, were examined in the period 2017-2018. The results obtained show significant differences (p < 0.01) between the parameter values under consideration relative to the year of cultivation (Factor A), seed population (Factor B) and mycorrhizal sees treatment (Factor C). In the first experimental year, there was an increase in the first count and total germination of 4 to 6 % compared to the control when pepper seeds were treated with the mycorrhizal formulation. In the second experimental year, an increase in the first count was in the range of 3 to 16 %, whereas an increase in the total germination was 3 to 4 %, compared to the control. The effect of mycorrhizal pepper seed treatment proved beneficial especially to aged seeds that were slow to germinate.

In addition to normal seeds, hard seeds of alfalfa have often been found after harvest. Such seeds prevent the penetration of water and gases into the seed interior, causing the reduction in germination. They do not tend to germinate even under ideal laboratory or field conditions, or they exhibit late germination. Consequently, they are of no relevance to planting crops. A decrease in the amount of hard seeds and an increase in germination can be achieved by scarification of acids, physical damage to the seed coat, hot water, cooling, etc. Temperature treatment scarification prior to sowing is a simple and inexpensive solution, safe for humans and the environment. The tests were carried out on three alfalfa cultivars: 'Medijana', 'Banat' and 'Zaječarska 83'. Their seeds were exposed to temperatures of 70 oC (for 10, 30, 60 and 90 minutes), 80 oC (for 10, 30, 60 and 90 minutes) and 90 oC (for 10, 30, 60 and 90 minutes). After the treatment under laboratory conditions, the germination rate and the share of hard/dormant seeds were investigated. The results obtained indicate that the increase in germination can be significant (p ≥ 0.05) provided temperature seed treatments are applied. Furthermore, the optimal temperature treatment was found to be essentially dependent on the specific alfalfa cultivar.