What Does Cold Damage Look Like in Phalaenopsis in Winter? An Analysis of Symptom Differences Among Varieties
Cold damage symptoms in Phalaenopsis: the symptoms shown in response to cold damage differ slightly among varieties. So what do cold damage symptoms in Phalaenopsis look like? Would you like to find out? Using the large red-flowered variety Phal. Taisuco Firebird as the test material, following the routine export packaging method
Cold damage symptoms in Phalaenopsis: the symptoms shown in response to cold damage differ slightly among varieties. So what do cold damage symptoms in Phalaenopsis look like? Would you like to find out?
Using the large red-flowered variety Phal. Taisuco Firebird as the test material, following the routine export packaging method, the plants were placed inside white paper bags, laid flat, and packed into cardboard boxes. Three temperatures of 12, 14 and 16°C were used to simulate potted dark low-temperature sea transport for one to five weeks, for a total of five treatments. Immediately after treatment, the plants were placed in a flowering greenhouse with a day temperature of 25°C and a night temperature of 18°C for flowering induction. In addition, plants not subjected to low-temperature treatment served as controls: control one was placed in a normal-temperature greenhouse, and control two was placed in the flowering greenhouse. After spike emergence and flowering, various flowering traits were investigated.
After the Phalaenopsis plants underwent this experiment's simulated potted dark low-temperature sea transport treatment, various cold damage symptoms of differing severity appeared. After summarising, they could be divided into 6 grades (in order: 0 normal, 1 mildest, 3 mild, 5 moderate, 7 severe, 9 most severe). Grade 0 showed no cold damage at all; grade 1 showed slight water-soaked symptoms on the leaves of some plants, usually occurring on only one leaf; grade 3 showed obvious water-soaked dark brown circular patches on the leaves, and the tissue within the patches clearly showed disintegration and necrosis; if this water-soaked dark brown necrotic tissue expanded to cover more than half the area of the leaf, and occurred on every leaf, then it was classified as grade 5; at grade 7 the cold damage was already quite severe, with the water-soaked necrotic tissue having expanded to cover most of the area of most leaves, and most of the plant's leaves had softened and drooped; when the cold damage grade was 9, all leaves of the plant showed a water-soaked, softened appearance accompanied by infection by miscellaneous microorganisms, the leaves detached at the base, and the plant could no longer stand upright at all.
The symptoms shown in response to cold damage differ slightly among varieties. In some varieties, the spread of water-soaked dark brown necrotic tissue on the leaves is often accompanied by a yellow halo around it, which appears to be a response of some kind of cold-resistance mechanism; therefore, when the cold damage grade was 7, the plants still appeared upright. Based on the above cold damage grades, the actual investigation results are shown in Table 1, which shows that for the large red-flowered Phalaenopsis variety Taisuco Firebird, using three temperatures of 12, 14 and 16°C, after simulated potted dark low-temperature sea transport for one to five weeks, the investigation results showed that the two control plants not subjected to low-temperature treatment showed no cold damage at all; at the two temperatures of 12 and 14°C, cold damage symptoms of varying degrees appeared during the simulation, with 12°C being more severe than 14°C, and the longer the simulated transport weeks, the more severe the cold damage, with even the phenomenon of all plants in an entire treatment rotting to death; however, at 16°C after five weeks of dark low temperature, the plants showed no obvious cold damage, with only a few plants showing slight yellow spot cold damage. After being moved into the flowering greenhouse, all plants treated at 12°C rotted to death and had no cultivation value at all; plants treated at 14°C varied depending on the treatment weeks, with 50-100% of plants having cultivation value; plants at 16°C all 100% had cultivation value.
The symptoms shown in response to cold damage differ slightly among varieties. In some varieties, the spread of water-soaked dark brown necrotic tissue on the leaves is often accompanied by a yellow halo around it, which appears to be a response of some kind of cold-resistance mechanism; therefore, when the cold damage grade was 7, the plants still appeared upright. Based on the above cold damage grades, the actual investigation results are shown in Table 1, which shows that for the large red-flowered Phalaenopsis variety Taisuco Firebird, using three temperatures of 12, 14 and 16°C, after simulated potted dark low-temperature sea transport for one to five weeks, the investigation results showed that the two control plants not subjected to low-temperature treatment showed no cold damage at all; at the two temperatures of 12 and 14°C, cold damage symptoms of varying degrees appeared during the simulation, with 12°C being more severe than 14°C, and the longer the simulated transport weeks, the more severe the cold damage, with even the phenomenon of all plants in an entire treatment rotting to death; however, at 16°C after five weeks of dark low temperature, the plants showed no obvious cold damage, with only a few plants showing slight yellow spot cold damage. After being moved into the flowering greenhouse, all plants treated at 12°C rotted to death and had no cultivation value at all; plants treated at 14°C varied depending on the treatment weeks, with 50-100% of plants having cultivation value; plants at 16°C all 100% had cultivation value.
