Growth period Management of Gladiolus cut Flower production Technology in Open Field (part two)

2. Fertilizer application amount

The amount of fertilizer applied in the planting site should be determined according to the soil conditions, and attention should be paid to the effect of pH on fertilizer efficiency. When the soil is alkaline, calcium superphosphate will be fixed and not easily absorbed by the root; if it is acidic soil, phosphorus is easy to be leached, resulting in the lack of phosphorus. When the pH is lower than 5, it is easy to cause fluoride toxicity. The loss of fertilizer is faster in sandy soil, but on the contrary in clayey soil. Fertilizer loss is also serious in the rainy season.

Of course, it is best to measure the fertilizer requirement of the plant by measuring the content of mineral elements in the plant. For producers, it is also an auxiliary means to judge fertility by observing the growth of gladiolus plants. Insufficient nitrogen fertilizer, lighter or even yellowed leaves often lead to poor plant growth, delayed flowering and reduced floret number. Supplementation of nitrogen fertilizer will increase flower branch weight and corm yield. If the leaves are dark green and weak, too much nitrogen fertilizer may cause soft and fragile flowers and branches, shorten florescence and increase the chance of infection. Lack of potash fertilizer, yellowing between veins of young leaves, shortening of plants and flower stems, and delayed flowering. Potassium dihydrogen phosphate can be used for foliar spraying. Adequate potassium fertilizer is beneficial to improve the quality of corms and the number of bulbs. Lack of phosphorus, young leaves dark green and old leaves purple, can be foliar spraying potassium dihydrogen phosphate or calcium superphosphate. Phosphate fertilizer is also beneficial to the absorption of nitrogen fertilizer.

Some trace elements are sometimes needed in the growth and development of Gladiolus, such as calcium, manganese, magnesium, boron, iron, copper and zinc. Calcium deficiency can cause inflorescence differentiation to stop or decrease, and even flower buds to wither. This phenomenon is easy to occur in soft water areas, and calcium fertilizer can be supplemented by spraying lime or foliar spraying calcium nitrate. Iron deficiency, there will be chlorosis between the veins, new leaves are easy to occur, serious will cause the leaves to become yellowish white. Iron deficiency is most likely to occur in alkaline soils, and iron availability can be improved by applying chelated iron (Fe-EDTA, etc.). Magnesium deficiency causes chlorosis of the old leaf margin and yellowing of the plant. However, too much magnesium increases the symptoms of calcium deficiency in plants. Lack of boron, the leaves become thicker and brittle, the leaf margin is easy to crack, deformed, and the inflorescence is dwarfed. But too much boron will cause the leaves to scorch. Trace elements can be sprayed in the soil or foliage to supplement.

Generally speaking, Gladiolus does not need much fertilizer and is sensitive to salt content, so fertilization should be timely and appropriate, and pay attention to the effects of chlorine and fluoride. Maintaining the nutritional balance among various fertilizer elements, including some trace elements, will achieve better results and ensure the good quality of cut flowers.

3. Lodging prevention

The plant of Gladiolus is tall, up to 1.2 to 1.5 meters. In the later growth stage, with the growth of inflorescence, the center of gravity of the plant rises, and it is easy to lodge in the event of wind and rain. After lodging, the flower stem bends upward, affecting the quality of cut flowers. Therefore, the production of permanent nylon mesh or plastic mesh, the net continues to improve with the growth of the plant, in order to maintain the vertical growth of the plant. In addition, when the new bulb of Gladiolus is replaced, the new ball is on the top, and the new root (traction root) is also close to the ground, but its growth and development mainly depends on the function of the new root, and the drought resistance of the plant is poor when it is planted shallowly, which is easy to affect the development of flowers. Therefore, it was found that the deep planting of 20cm to 30cm was beneficial to the growth of the plant, the weight of the new bulb increased and the Internode of the corm elongated. Some experiments have proved that covering soil can also play a role in deep planting in the process of cultivation. After three times of soil mulching at the budding stage, the four-leaf stage and the flowering stage, the plant was not only robust but not lodging, but also the weight of the new ball increased. The test showed that the endogenous growth inhibitory substances in the deep-planted corms were less than those in the shallow-planted ones.