Trace Elements and Sugarcane
Sugarcane crop has tremendous potential to increase the farmers income, however the deficiency of micronutrients is one of the major constraints in improving the sugarcane productivity and quality of cane juice.
Trace elements, also known as micronutrients, are required for a plant’s proper growth and development. Although a plant requires a very small amounts of trace elements, they are essential for the plant’s physiological processes. Trace element deficiency symptoms include stunted growth, yellowing leaves, and poor development.
Micronutrients are unquestionably necessary for plants to remain healthy and develop the ability to benefit people who eat them. For plants to grow healthily and lushly, these micronutrients must reach to the plants. A proper distribution of micronutrients is important for optimal outcomes.
The two micronutrients that are most restricting in sugarcane production areas are zinc (Zn) and boron (B). Numerous studies have examined the theory that Zn and B applications during planting influence sugarcane yield, both during the initial crop cycle and subsequent crop cycles.
Boron:
Despite being crucial to the health and quality of sugarcane, boron is frequently the micronutrient most lacking in sugarcane plantations. In addition to being essential for many fundamental activities, boron is also very important for sugarcane production.
Role of Boron:
- Boron helps in new shoot and secondary roots development.
- Boron aids in efficient utilization of other nutrients including calcium, nitrogen, and potassium.
- Boron is critical for the uptake of calcium (Ca) and helping improve Ca movement through the plant.
- When high levels of Ca are being applied, additional boron may be needed to maximize Ca uptake.
Boron is also required for cell division and cell walls formation, leaves development, nucleic acids synthesis and carbohydrates metabolism and sugars transportation through the cell membranes.
Factors Affecting B Availability and Uptake:
- High pH (>pH 7.5)
- Sandy soil with low CEC – Leaching
- Drought stress may increase B deficiency
- High light intensity and long day conditions also increase B deficiency
Boron Deficiency:
- Necrotic and crinkly leaf tips.
- Drying up of the apical bud or retarded apical growth.
- Small, narrow, and somewhat chlorotic young leaves.
- Young sugarcane plants bunched with many secondary stalks.
- The spindle leaves turn white and dry out.
Symptoms of “pokkahboeng,” a disease caused by Fusarium monoliforma and damage from the pesticide Dalapon, can resemble a boron deficiency.
Zinc:
Zinc is a well-known component of enzymes and plays a significant role in photosynthesis, auxin activity, plant hormone balance, fruit, seed, and root formation, early developmental phases, and more.
In the plant’s metabolism, zinc is essential for tryptophan synthesis, the precursor of indoleacetic acid (AIA), responsible for the enzyme production that promotes the lengthening and growth of cells. Zinc is also involved in the activation of several enzymes.
Role of Zinc:
- Chlorophyll biosynthesis
- Increases productivity and tillering
- Better vegetative growth and greenness
- Proper internode development
Factors Affecting the Availability of Zinc in Soil:
- High pH (>pH 7.5) – saline / alkaline soil
- Too low or too high organic matter
- Standing water and low temperature
- Excess phosphorus in soil
Zinc Deficiency:
The tillering, growth, and longevity of the ratoon in sugarcane plants are all adversely impacted by zinc deficiency. Younger leaves will be the first to have a zinc deficiency. When zinc levels in sugarcane are low, the following visual characteristics may observe –
- Chlorotic stripes on the leaf blade.
- Shortening of internodes in the stalks.
- Formation of “reels,” reduction of tilling.
- Thinner stalks that may lose turgidity.
In more severe situations, there is necrosis of leaves from the tip. Additionally, sugarcane plants deficient in zinc are more susceptible to fungus attacks, which can lead to the appearance of red stains on the leaves.
