1. Important physiological functions of copper
Copper is involved in many metabolic processes
Copper is an essential element for photosynthesis, respiration, carbon metabolism, nitrogen metabolism, and cell wall synthesis.
Copper has a stabilizing effect on chlorophyll and can prevent premature destruction of chlorophyll;
Participates in the formation of nitrogen-fixing root nodules.
Copper also promotes the lignification process.
Copper promotes pollen formation.
Copper plays a role in inhibiting fungi, resisting drought, fighting severe weather and other adversities.
Copper is mainly absorbed as Cu2+ and Cu+, and soil organic matter can increase the activity of copper.
Copper is a metal prosthetic group for many oxidases
Copper participates in the formation of oxidases that can resist oxidative stress, such as:
1) Superoxide dismutase (CuZn-SOD) participates in fighting reactive oxygen species O2-,
2) Ascorbic acid oxidase (APX) can oxidize ascorbic acid to produce water and dehydroascorbic acid
3) Polyphenol oxidase (CAT) can oxidize monophenols into diphenols and then into quinones. Quinone compounds can polymerize to form brown-black compounds, which ultimately form humus.
Copper is also involved in the formation of plastocyanin enzyme. Plastocyanin is an important member of the photosynthetic chain and is responsible for transferring electrons. Its oxidation state is blue and its reduced state is colorless.
2. Symptoms of copper deficiency in plants
Newly reclaimed land is prone to copper deficiency
The first nutritional disease that occurs when plants are grown on newly reclaimed acidic organic soil is usually copper deficiency, a condition often referred to as “reclamation disease.” The subsoil of organic soils in many areas contains sediments such as marl, phosphate limestone or other calcareous substances that adversely affect the availability of copper, making copper deficiency very complicated. In other cases, soil copper deficiency is not widespread.
“Reclamation disease”, also known as “reclamation disease” that often occurs in herbaceous plants, is due to copper deficiency. It is often found on barley planted in newly reclaimed land that the tips of diseased plants turn yellow or brown, gradually wither, the ears are deformed, and the seed setting rate is low, all of which are caused by copper deficiency.
Main manifestations of copper deficiency in plants
Copper deficiency in plants generally manifests as withered tops, shortened internodes, white leaf tips, narrow, thin, and twisted leaves, stunted development of reproductive organs, and cracked fruits. Different plants often show different symptoms.
The sensitivity to copper deficiency varies greatly among crop varieties. The sensitive plants are mainly oats, wheat, barley, corn, spinach, onion, lettuce, tomato, alfalfa and tobacco, followed by cabbage, sugar beet, citrus, apple and Tao et al. Among them, wheat and oats are very good indicator crops for copper deficiency. Other crops that respond strongly to copper are hemp, flax, rice, carrots, lettuce, spinach, sudangrass, plums, apricots, pears and onions.
Plants that are tolerant to copper deficiency include beans, peas, potatoes, asparagus, rye, grasses, lotus root, soybeans, lupins, oilseed rape and pine trees. Rye has a unique tolerance to copper-deficient soil. Some people have done comparative experiments. In the absence of copper application, wheat completely failed to produce crops, while rye grew robustly.
3. Copper in the soil and copper fertilizers on the market
Copper-containing minerals in soil include chalcopyrite, chalcocite, bornite, etc. The concentration of copper in the soil solution is very low, and most of the copper is adsorbed by soil clay particles or bound by organic matter. In newly reclaimed soil, copper deficiency, also known as “reclamation syndrome”, often appears first. The most commonly used copper fertilizer is gallite (CuSO4·5H2O), which is copper sulfate pentahydrate, which has good water solubility. Generally used for foliar spraying. Chelated trace element activator contains copper and can be used for soil application and foliar spraying.
Post time: Aug-12-2024
