The invention discloses a potato expanding propagation method. The potato expanding propagation method comprises the measures of potato seed
seedling growth,
seedling breaking-off and
transplantation,
soil preparation and field management. The method comprises the following steps of cultivating short strong buds by using potato seeds; selecting
loam which is flat and facilitates
irrigation and drainage, wherein
solanaceae crops such as potatoes, hot pepper and eggplants are not planted in the
loam for over two years;
sowing seeds in the last ten-day period of March; manufacturing a potato
bed, wherein the width of the potato
bed is 90cm, and the depth is 20cm; in the seed
sowing process, enabling tubers to meet the conditions that the
umbilical region of each tuber faces downwards, the top of each tuber faces upwards, and spacing between every two potatoes is 3cm; performing
seedling breaking-off and
transplantation when the length of seedlings reaches 3-5cm and the
root length is about 5cm; digging a pond in the
transplantation process, wherein the line spacing is 50-53cm, the row spacing is 29-33cm, and the depth of the pond is 13-15cm; planting the seedlings which are broken off in the pond in a
single plant form, burying white parts and roots into soil, and applying a sufficient amount of root fixing water; when new roots grow within 10-15 days, switching a growth mode into a normal farmland management mode. Compared with a potato-
cutting seed-
sowing mode, a seedling breaking-off transplantation expanding propagation mode has the advantages that the cost is reduced by over 30 percent, and the propagation path of various sources of diseases from which the potatoes suffer in the seed cultivation process are avoided to the greatest extent.