The invention provides a method for increasing the
apomixis ratio of apple rootstocks and the trimming degree of nursery stocks. According to the method, before
pollination and fertilization of apple flowers are finished,
lime sulfur at the concentration of 1.0 baume degree is sprayed on the apple flowers at the full-blossom stage for one time in the
morning or in the
evening every day (the flowers are sprayed uniformly until the petals are wet and liquid does not drop off), continuously for three days. When the
lime sulfur is sprayed on the apple flowers, the stigma activity is reduced, seriously, the stigma is wilted and the life of the stigma is shortened, so that the
effective time of
pollination and fertilization is shortened, the fertilization of the
embryo sac is limited, the fertilization process of the 2N
embryo sac of the apples with the apomictic feature is avoided, and the unfertilized 2N
embryo sac forms clonal seeds through the
apomixis way. By adoption of the
lime sulfur, the life of the stigma is shortened and the
pollination time is shortened, so that the
apomixis ratio of the apple
rootstock seeds with the apomictic feature and the trimming degree of the nursery stocks are increased.