Gladiolus Cut Flower Open-Field Production Technology: Growth Period Management (Part 1)
Growth Period Management in Open-Field Production Technology for Gladiolus Cut Flowers (Part 1)
I. Water
Before the gladiolus emerges, the soil must be kept moist so that the corms can root quickly. Generally, the soil water-holding capacity should be around 25%, while the soil aeration conditions should maintain a porosity of between 5% and 10%. The 3-to-7-leaf stage is the period of flower bud differentiation and inflorescence elongation, and also the period when contractile roots form and grow rapidly; once the water supply is insufficient, cut flower quality will be noticeably affected. If the corms are to be harvested after flowering, stop watering 1 to 2 weeks before lifting the corms. For field irrigation of gladiolus, sprinkler irrigation and drip irrigation are preferable, as they can maintain a good soil structure, raise the ambient air humidity, prevent leaf tips from scorching, and also save water. Irrigation can be carried out in the morning, which helps lower the temperature near the leaves during the day and raise the relative air humidity, while keeping the plants drier at night, which helps reduce disease attack. When planting in the open field, areas and seasons with abundant rain require special attention to drainage and waterlogging prevention to avoid rhizome rot. In particular, if flooded at the 3-to-4-leaf stage, the flower spikes cannot emerge. Prolonged waterlogging makes the flower spikes weak and prone to breaking, the flowers small, and scorching of the leaf tips more severe, causing the cut flowers to lose their commercial value.
II. Fertilization
Gladiolus prefers fertile soil, but too much fertilizer should not be applied either. Correct fertilization should be based on the specific conditions of soil type, soil fertility and salt content. Applying organic fertilizer helps improve soil structure, and at the same time can avoid a soil salt content that is too high due to heavy application of chemical fertilizers. Gladiolus is very sensitive to soil salinity. If the salt content is too high, it will inhibit root growth and water uptake, thereby affecting the growth of the whole plant and reducing cut flower quality. Special attention should be paid to the adverse effects of fluorine and chlorine on gladiolus; when using phosphate fertilizers, they must never contain fluorine. For this reason, triple superphosphate (which easily contains a relatively high concentration of fluorine) should be used as little as possible, and other phosphate fertilizers used instead, to prevent scorching of the leaf tips.
1. Application Timing
Fertilization can be carried out multiple times throughout the entire growth cycle of gladiolus, including the base fertilizer before planting and 3 topdressings during the growth period.
The base fertilizer is mainly organic fertilizer. Decomposed organic fertilizer can improve the physical structure and chemical properties of the soil, making the soil loose with good aeration, conducive to water and fertilizer retention and promoting root growth; moreover, organic fertilizer has slow-release and long-lasting characteristics, ensuring a sufficient nutrient supply throughout the entire plant growth cycle. The application rate of organic fertilizer should be determined according to the original fertility of the soil. Generally, the soil organic matter content should be maintained at around 2% to 3%. Chemical fertilizers are mainly used as topdressing. Chemical fertilizers are characterized by quick action and strong leaching loss, so they should not be applied heavily in the base fertilizer. This is because after planting, the plant root system has not yet fully developed; a large application rate of chemical fertilizer causes soil salinity to rise, which instead affects normal plant growth. Phosphate fertilizer is not easily leached from the soil, so it can be applied together with the base fertilizer, provided the salt concentration is taken into account. In short, the soil must be analyzed and evaluated before fertilization so that rational fertilization can be achieved.
During the growth period of gladiolus, 3 topdressings should be applied: the first when the gladiolus plants grow to the 2-to-3-leaf stage. This is the flower bud differentiation stage, and the nutrients stored in the corms have already been largely consumed; if water and fertilizer are lacking, the number of florets in the inflorescence will decrease and cut flower quality will decline. This fertilization is mainly nitrogen and potassium fertilizer. The second is at the 5-leaf stage. At this time the flower stem elongates rapidly and individual florets develop faster; the fertilizer is mainly phosphate and potassium fertilizer, which can promote thick and sturdy flower spikes, large and brightly colored flowers, and a long vase life after harvest. The third is after the cut flowers are harvested. This is the period of growth and development of the new corms and cormels, which need fertilizer to support corm growth. The plumpness of the corms and the amount of stored nutrients directly affect the growth vigor of the following year, while the number of cormels affects the propagation rate. Therefore, topdressing after flowering is very important and must not be neglected. Topdressing can be carried out by combining root application with foliar application as a supplement, and combined with irrigation to give full play to fertilizer efficiency. The chemical fertilizers used for topdressing gladiolus include ammonium nitrate, potassium nitrate, calcium superphosphate, monopotassium phosphate, ammonium sulfate, potassium sulfate, urea, etc. Use potassium chloride and fluorine-containing phosphate fertilizers sparingly.
Before the gladiolus emerges, the soil must be kept moist so that the corms can root quickly. Generally, the soil water-holding capacity should be around 25%, while the soil aeration conditions should maintain a porosity of between 5% and 10%. The 3-to-7-leaf stage is the period of flower bud differentiation and inflorescence elongation, and also the period when contractile roots form and grow rapidly; once the water supply is insufficient, cut flower quality will be noticeably affected. If the corms are to be harvested after flowering, stop watering 1 to 2 weeks before lifting the corms. For field irrigation of gladiolus, sprinkler irrigation and drip irrigation are preferable, as they can maintain a good soil structure, raise the ambient air humidity, prevent leaf tips from scorching, and also save water. Irrigation can be carried out in the morning, which helps lower the temperature near the leaves during the day and raise the relative air humidity, while keeping the plants drier at night, which helps reduce disease attack. When planting in the open field, areas and seasons with abundant rain require special attention to drainage and waterlogging prevention to avoid rhizome rot. In particular, if flooded at the 3-to-4-leaf stage, the flower spikes cannot emerge. Prolonged waterlogging makes the flower spikes weak and prone to breaking, the flowers small, and scorching of the leaf tips more severe, causing the cut flowers to lose their commercial value.
II. Fertilization
Gladiolus prefers fertile soil, but too much fertilizer should not be applied either. Correct fertilization should be based on the specific conditions of soil type, soil fertility and salt content. Applying organic fertilizer helps improve soil structure, and at the same time can avoid a soil salt content that is too high due to heavy application of chemical fertilizers. Gladiolus is very sensitive to soil salinity. If the salt content is too high, it will inhibit root growth and water uptake, thereby affecting the growth of the whole plant and reducing cut flower quality. Special attention should be paid to the adverse effects of fluorine and chlorine on gladiolus; when using phosphate fertilizers, they must never contain fluorine. For this reason, triple superphosphate (which easily contains a relatively high concentration of fluorine) should be used as little as possible, and other phosphate fertilizers used instead, to prevent scorching of the leaf tips.
1. Application Timing
Fertilization can be carried out multiple times throughout the entire growth cycle of gladiolus, including the base fertilizer before planting and 3 topdressings during the growth period.
The base fertilizer is mainly organic fertilizer. Decomposed organic fertilizer can improve the physical structure and chemical properties of the soil, making the soil loose with good aeration, conducive to water and fertilizer retention and promoting root growth; moreover, organic fertilizer has slow-release and long-lasting characteristics, ensuring a sufficient nutrient supply throughout the entire plant growth cycle. The application rate of organic fertilizer should be determined according to the original fertility of the soil. Generally, the soil organic matter content should be maintained at around 2% to 3%. Chemical fertilizers are mainly used as topdressing. Chemical fertilizers are characterized by quick action and strong leaching loss, so they should not be applied heavily in the base fertilizer. This is because after planting, the plant root system has not yet fully developed; a large application rate of chemical fertilizer causes soil salinity to rise, which instead affects normal plant growth. Phosphate fertilizer is not easily leached from the soil, so it can be applied together with the base fertilizer, provided the salt concentration is taken into account. In short, the soil must be analyzed and evaluated before fertilization so that rational fertilization can be achieved.
During the growth period of gladiolus, 3 topdressings should be applied: the first when the gladiolus plants grow to the 2-to-3-leaf stage. This is the flower bud differentiation stage, and the nutrients stored in the corms have already been largely consumed; if water and fertilizer are lacking, the number of florets in the inflorescence will decrease and cut flower quality will decline. This fertilization is mainly nitrogen and potassium fertilizer. The second is at the 5-leaf stage. At this time the flower stem elongates rapidly and individual florets develop faster; the fertilizer is mainly phosphate and potassium fertilizer, which can promote thick and sturdy flower spikes, large and brightly colored flowers, and a long vase life after harvest. The third is after the cut flowers are harvested. This is the period of growth and development of the new corms and cormels, which need fertilizer to support corm growth. The plumpness of the corms and the amount of stored nutrients directly affect the growth vigor of the following year, while the number of cormels affects the propagation rate. Therefore, topdressing after flowering is very important and must not be neglected. Topdressing can be carried out by combining root application with foliar application as a supplement, and combined with irrigation to give full play to fertilizer efficiency. The chemical fertilizers used for topdressing gladiolus include ammonium nitrate, potassium nitrate, calcium superphosphate, monopotassium phosphate, ammonium sulfate, potassium sulfate, urea, etc. Use potassium chloride and fluorine-containing phosphate fertilizers sparingly.