I. Poor Quality Manifestations
The main manifestations of poor quality in albino tea include overgrowth of new shoots, distortion of buds and leaves, hindered recovery to green, and physiological disorders.
1. Overgrowth of New Shoots
Overgrowth is the mildest manifestation of poor quality. When new shoots develop to have two or three leaves, they no longer produce new leaves but instead show a significant increase in stem length. The length of a one-bud-two-or-three-leaves shoot can reach over 10 cm, sometimes even exceeding 15 cm. These buds and leaves are well-albino, but due to their excessive length, they are unsuitable for flat or strip-shaped tea processing. However, there is still room for processing into coiled or curled teas. This phenomenon is more likely to occur in leaf-white type albino teas.
Morphology of Overgrown Albino Shoots
2. Distortion of Buds and Leaves
Distortion primarily occurs in tea buds that sprout later during lower temperatures. It is characterized by hooked bud shapes, hardened green stems, long and slender leaves resembling willow leaves, twisted leaf surfaces with asymmetric veins, irregular leaf margins, and Snow-white coloration that is hard and thin. These buds and leaves cannot be processed into normal fresh leaf shapes, and the finished product exhibits a pronounced bitterness. Distorted buds and leaves recover to green slowly, and their shape cannot be restored. However, the second flush after leaving the shoots will resume normal development.
Morphology of Distorted Albino Buds and Leaves
3. Hindered Recovery to Green
The buds and leaves are small and have a milky yellow or yellowish-white color. They cannot develop normally, and when the typical season for recovery to green arrives, this condition cannot be repaired. As a result, the buds and leaves, and eventually the entire plant, gradually die.
Hindered Recovery to Green of Albino Buds and Leaves
4. Physiological Disorders
Highly albino shoots exposed to strong winds and intense sunlight exhibit reduced resilience, leading to damage of the buds and leaves. After high levels of albinism, the leaf texture becomes thinner, and tender buds and leaves can develop scorched edges and tips when subjected to strong winds. Mature leaves exposed to bright sunlight can also show scorched edges and leaves. This physiological disorder, when occurring in young highly albino tea plants, can cause a rapid decline in vigor, growth inhibition, and even death.
Sunburn Damage on Albino Buds and Leaves
Among the four manifestations of poor quality, the physiological disorders in highly albino leaves are generally similar across varieties. The hindered recovery to green phenomenon was only observed in a few cases in the seedling stage of White Leaf No.1 grown in coastal areas. Overgrowth and distortion primarily occur in leaf-white types, especially in White Leaf No.1.
II. Causes of Poor Quality
White Leaf No.1 experiences an obstacle in cell membrane development, leading to inhibited chlorophyll synthesis and the accumulation of amino acids as metabolic intermediates, resulting in high levels of amino acids in the plant.
Chlorophyll not only serves as the tissue for nutrient production but also absorbs light energy and maintains thermal balance within the plant. Normally, it transitions from a nutrient consumption phase to a nutrient accumulation phase after the second leaf has developed. Throughout the Spring Tea period, buds and leaves that remain highly albino experience inhibited chlorophyll synthesis, maintaining low levels. Early sprouting shoots cannot timely produce and accumulate nutrients, and subsequent buds and leaves lack supplementation, causing nutrient depletion. This leads to two phenomena: amino acid levels do not rise with increased albinism, and the albinism intensifies, leading to distortion.
If temperatures continue to remain within the range suitable for albinism, later sprouting buds from highly albino plants are more likely to exhibit poor quality. Weak varieties and gardens, gardens that suffered severe frost and leaf loss in winter, highly albino buds and leaves, and later sprouting buds in easily albino gardens will show more obvious signs of distortion.
Different temperature conditions, shading cultivation, and Fertilizer application trials found that temperature during sprouting is the most critical factor determining the degree of distortion. In warmer regions or with measures such as mulching to raise temperatures, the degree of albinism can be reduced while completely eliminating poor quality in new shoots. Increasing the overall level of fertilizer supply throughout the year, particularly applying nitrogen Fertilizers before spring or before albinism begins, can significantly reduce the degree of albinism and promote robust growth of new shoots, somewhat alleviating the distortion of later sprouting buds under continuous low temperatures. However, foliar applications of macronutrients like nitrogen, phosphorus, and potassium or micronutrients like zinc and magnesium during the period of albinism do not effectively promote growth, indicating that highly albino leaves cannot effectively absorb these nutrients to improve their metabolism.
Due to the lack of chlorophyll and thin leaf texture, highly albino buds and leaves quickly lose water and wilt at the edges and tips under strong winds, leading to scorched tips and edges. Under continuous sunlight, the leaf temperature rises, accumulating to a point where scorching occurs.
Overgrowth primarily occurs in early sprouting buds under low-temperature conditions. The overall morphology of the buds appears normal, except for the continuous increase in stem length without further leaf development until the terminal bud forms. If not picked, the stem begins to recover to green.
III. Control Measures
(a) Young Garden Control
Poor quality control in young gardens mainly focuses on protecting highly albino leaves from physiological disorders. During the first year of planting, due to delayed sprouting, albinism typically does not occur, which is beneficial for plant development. However, when albinism does occur, the consequences for the plant can be severe. In the second year, if the spring shoots are not picked, highly albino spring shoots are prone to sunburn. In such cases, shading cultivation is a crucial measure. Typically, shading nets are used when the shoots have developed two or three leaves, and then removed after the shoots recover to green, ensuring the shoots are protected from sunburn.
(b) Production Garden Control
1. Increase Fertilizer Application
For gardens prone to high levels of albinism, the amount of fertilizer should be increased, typically applying 150 kg or more of Cake fertilizer per mu along with 10% of the base fertilizer as chemical fertilizers. If necessary, apply an appropriate amount of chemical fertilizers before spring or during the mid-harvest of spring tea to increase the nitrogen supply to the tea plants and reduce the level of albinism.
2. Protective Cultivation
Gardens susceptible to frost and leaf drop should implement protective measures such as planting windbreaks and inter-row mulching to prevent leaf loss. In cases of severe frost, measures such as greenhouses should be used to establish protected cultivation.
3. Timely Picking
Since leaving highly albino buds and leaves can lead to physiological disorders and negatively impact subsequent growth, timely picking, leaving the fish scale leaf, is the most direct control measure for highly albino gardens.