Some suggestions on choosing seedling containers

1. Number of holes and hole volume

The number and volume of the holes in the plug tray directly affect the quality of seedling growth. Too few holes in the plug tray will cause a waste of production resources and means of production; too many holes in the plug tray will result in insufficient space for seedling growth, making the seedlings weak and susceptible to diseases. The shape of the holes should be a square inverted trapezoid or an inverted cone, which is conducive to guiding the roots to extend downward, rather than the roots entangled on the inner wall as in round or side vertical holes. The drainage and air permeability holes at the bottom of the plug tray provide more favorable conditions for drainage and ventilation of the substrate. Generally speaking, the smaller the volume of the plug tray planting holes, the more sensitive the plug tray seedlings are to changes in humidity, nutrients, oxygen, pH value, and EC value in the substrate; the larger the volume of the plug tray planting holes, the greater the substrate content and the stronger the buffering capacity, which is conducive to the growth of the root system. According to the seedling variety and the final seedling size, the number and volume of the plug tray holes should be reasonably selected to reduce the amount of substrate, increase space utilization, and thus save production costs.

Table 1: Specifications of plug trays for common varieties