Diagnostics of chrysanthemum inflorescence deformation and agrotechnology of freesia cultivation

Agronomists often encounter flower head deformation in chrysanthemums of the cultivar Balcombe Perfection and its sports. In this disorder, buds open slower than usual and appear flattened. In damaged flowers, the ray florets curl, making them look like tubular ones, and the flower heads themselves bend as they open. As a result, the entire flower head becomes shriveled.

Freesia cultivation practices

Freesia is grown in greenhouse beds. Before planting, the soil must be disinfected by steaming or treating with methyl bromide. Freesia can be cultivated year-round from seed, corms, or cormels (offsets). The period from planting to flower harvesting takes from 18 to 35 weeks: this period decreases in winter and increases in summer.

• Growing period from seed — 19—12 months
• Growing period from cormels — 7—10 months
• Seed sowing depth — 5 mm
• Sowing distance for seeds — 8x8 cm
• Yield of flowering shoots — 1.5–4 per plant

To accelerate seed germination and facilitate water absorption, the seed coat is slightly damaged before sowing. The preparation procedure involves sequential steps for treating seed material before sowing into the soil. Thorough adherence to the technology guarantees uniform emergence.

1. Seed scarification to breach the seed coat integrity.
2. Soaking seeds in warm water for 24 hours.
3. Drying seeds between sheets of paper until dry.
4. Sowing prepared material into the soil.

Temperature regime directly affects the speed of freesia development and the quality of flowering. Upon the appearance of the fifth leaf, the plants initiate floral bud development, which concludes in six weeks. The optimal soil temperature for maximum flower yield is 13—17 °С. If the temperature drops below this, stems become shorter, and at higher values, flowering is delayed.

Flower harvesting begins 8—12 weeks after bud formation. During this period, it is necessary to strictly control the air temperature in the greenhouse depending on the growing season. The optimal microclimate parameters for summer and winter crops differ.

After harvesting the flowers, the corms are left in the soil for maturation, which is especially important for the formation of cormels around the base of the mother corm. The collected planting material is stored at 13—15 °С. To break the dormancy of the corms, they are heated for 13 weeks at 30 °С, completing the heating process one month before planting. Floral bud development in treated corms begins 6 weeks after thermal treatment, which corresponds to approximately 2—6 weeks after planting.

Corms are planted shallowly, lightly covered with soil. When growing them, the same temperature regimes are observed as for plants from seeds. Planting density varies depending on the category of planting material.