The invention belongs to the technical field of
agriculture and discloses a watermelon
seedling culturing substrate, which comprises the following components:
earthworm cast,
vermiculite, pearlstone and
paclobutrazol, wherein the volume ratio of the
earthworm cast to the
vermiculite to the pearlstone is (2-3):0.6:0.4; and the dosage of the
paclobutrazol is between 10 g / m<3> and 20 g / m<3>. When the substrate is used for culturing watermelon own-rooted seedlings, a
nutrient solution does not need to be replenished, the seedlings are in order and strong without growing excessively, and the root systems are developed. After the substrate is planted into soil along with the seedlings, beneficial microorganisms in the substrate can quickly form a dominant microflora around the rooting zone of a
crop, so that
nutrition elements in the soil can be activated, and the utilization ratio of a
fertilizer is increased; the application amount of an
inorganic fertilizer can be reduced by 20-30 percent; soil-borne diseases can be resisted effectively, the incidence rate of field
blight is low, and the
control effect is between 86.74 percent and 89.4 percent, is higher than the
control effect of an efficient bactericide for an own-rooted
seedling growing from the ordinary substrate, and is basically close to the
control effect of a grafted
seedling; and the soluble
sugar content of watermelon and the yield are increased.