Seeds of maize (Zea mays L.) and sorghum [Sorghum bicolor (L.) Moench.] were submitted to different osmotic potential levels induced by polyethylene glycol (PEG) with the objective of evaluating the effects of drought stress on seed germination and early seedling growth. Seeds were arranged in paper rolls and soaked in PEG solutions prepared with osmotic potentials 0.0 (control), -0.2, -0.4, and -0.8 MPa and kept into a seed germinator, at 25 °C for 18 days. A completely randomized design in a 2 × 4 factorial scheme with four replications of 50 seeds each was used. The results showed that by increasing of the osmotic potential level, germinated seed number, germination rate index, root and shoot length, shoot and root dry matter, and seedling vigor index (SVI) decreased, while mean germination time (MGT) and root: shoot ratio (RSR) increased in both crops. Additionally, the maize was more susceptible than sorghum to drought stress, with germination response declining more rapidly with decreasing osmotic potential. Sorghum crop tolerates water stress of up to -0.2 MPa, without reducing germination of the seeds; however, the growth of shoots and roots are inhibited. Drought stress limits the process of seed germination and early growth of maize seedlings.

The use of high quality seedlings is a key factor for the success of vegetable production, and the container size and design characteristics of the containers are important determinants of seedling quality. A experiment was conducted to investigate the effects of different container types on quality of cucumber seedlings (Cucumis sativus L., cv. Aodai Melhorado). Seedlings were grown in a seedling nursery with shadow protection at 50% in different containers: (i) 128-cell trays; (ii) 64-cell trays; (iii) tubes of 120 cm3; and (iv) plastic cups of 180 cm3. The plant height, diameter, root length, shoot dry matter, root dry matter, sturdiness quotient (SQ), shoot:root dry matter ratio (SRR) and Dickson quality index (DQI) were measured at 21st days after sowing. The production of cucumber seedlings in 64-cell trays, polypropylene tubes of 120 cm3 and plastic cups of 180 cm3 resulted in the highest values for the majority of investigated traits. The tray of 128-cells results in lower quality cucumber seedlings compared to other containers. Tubes with volume of 120 cm3 and plastic cups with volume of 180 cm3 are more appropriate containers for the production of high quality cucumber seedlings. The DQI is a good indicator of the standard of quality of cucumber seedlings.