An Analysis of the Relationship Between Plant Nutrient Deficiency Symptoms and the Streaking Phenomenon
When introduced, the outer petals opened rounder and more compact than this year's, and the colors were somewhat richer too; the main petal and the center gave an overall impression of grandeur. This year the center is neat and well-formed, with a tender green color and texture; the outer petals are somewhat thin in substance, the tight edging is not good enough, and the petal tips are pointed to the point of curling backward, so the flower's staying quality is likely to be less than ideal.
When we grow orchids, most of us use coarse materials, which are inherently low in nutrients, and combined with frequent leaching, nutrient deficiency is inevitable. When I first started growing orchids, I was very uneasy about coarse materials, and even back then I considered that trace elements would inevitably be lacking.
Let us first look at the symptoms of trace element deficiency:
Magnesium deficiency: the veins remain green while the areas between the veins turn yellow, sometimes purple, with necrotic spots appearing.
Iron deficiency: interveinal chlorosis, presenting a clear net-like pattern, sometimes appearing mosaic-like, and in severe cases the entire leaf turns white.
Boron deficiency: young leaves are deformed and wrinkled. Irregular chlorosis occurs between the veins.
Zinc deficiency: small leaves clustered together, spots appearing on both sides of the leaf surface, the plant stunted, and the internodes shortened. Mild cases resemble iron deficiency.
Copper deficiency: leaves lose their green color, leaf tips turn white and curl into a paper-twist shape, necrotic spots appear on the leaves, and the plant then withers and dies.
Manganese deficiency: necrotic spots appear between the veins, and dark green stripes appear along the veins in a rib-like pattern.
All of the above items resemble the streaking I have seen in disease diagnosis.
Let us then discuss viral diseases. We often see wheat rosette dwarf disease, maize rough dwarf disease, mosaic disease, albino disease, and so on. They are all viral diseases, but they all occur only sporadically. There has never been a large-scale outbreak; although they are transmitted by insects and through the soil, the probability of transmission is very low. The incidence rate is also very low, almost negligible in agriculture.
But then why do our orchids have so many viral diseases? Is it that we have all mistaken nutrient deficiency for streaking? The answer is yes; many of the streaking cases in disease diagnosis, I believe, are actually nutrient deficiency symptoms.