China Aster (Callistephus chinensis)
Nitrogen (N)
Symptoms
- Deficiency symptoms are first seen in older and lower leaves.
- Yellowing of older leaves is observed while the veins remain green in color.
- Delayed flowering
- Delayed production of flowers resulting in fewer blooms
- Deficiency causes necrosis of leaves
- Under extreme deficiency, premature leaf drop occurs
- The Stunted appearance of the plant are observed
Management
- For determining the severity of the deficiency, soil analysis has to be done
- Application of quick releasing nitrogen fertilizer like urea, according to the results of the soil test.
- Apply urea as a foliar spray (10 gram per litre of water) once every 15 days.
- Frequent application of organic growth boosters is also beneficial
Phosphorus (P)
Symptoms
- Symptoms will be first noticed in older and lower leaves.
- Foliage becomes dark green colour
- Purple/reddish discoloration particularly on the undersides of leaves
- Insufficiency leads to distorted flowers, delayed flowering or failure to produce flowers
- Deficiency leads to weakened & undeveloped root systems which may affect the uptake of nutrients.
- Severe deficiency causes thinner stems.
- The petals, blooms, and overall plant development are all drastically reduced.
Management
- Ensure that recommended amount of fertilizer is applied on regular time.
- For determining the severity of the deficiency, soil analysis is to be done
- Use fertilizers such as single superphosphate for quick correction or bone meal or rock phosphate for long-term correction.
- In the pH range of 6.5-7.5, phosphorus is readily absorbed by the roots.
- Addition of biofertilizers including phosphorus solubilizing bacteria along with organic manure helps to increase the availability of phosphorus
Potassium (K)
Symptoms
- Potassium is a highly mobile element in plant.
- So the deficiency symptoms will be first noticed in older and lower leaves.
- Deficiency symptoms first appear as pale to lemon-yellow margins on older leaves.
- This is followed by browning and necrosis of leaf margins.
- The branching of plant is greatly affected.
- Low potassium level cause reduction of the length and weight of stems and roots.
- The number and size of flowers will be adversely affected.
Management
- In the pH range of above 6, Potassium is readily available.
- Maintain pH by addition of lime/dolomite
- Improve the soil fertility by adding organic matter and wood ash.
- For determining the severity of the deficiency, soil analysis is to be done
- Use Muriate of Potash (MOP) according to the results of the soil test. Split application is preferable.
- Apply foliar sprays of sulphate of potash (SOP) (10 g/litre of water) and wetting agents in the morning as an immediate remedy
Calcium (Ca)
Symptoms
- Deficiency is first seen in growing points, younger leaves and developing fruits.
- Affected leaves appear as curled, twisted or distorted in shape
- Leaf necrosis leading to brown/black spots on leaf edges/tips
- Deficiency weakens stem & stalks
- Insufficiency of calcium cause breakage or bending of flowers, and delay in the opening of flowers.
- Young leaves develop a yellow halo at the tips before turning black and spreading down the leaf blade.
- A weakened & under developed root system contributes poor nutrient uptake & absorption of water.
- Calcium deficient plant results in fewer blooms, shorter stems, and slower overall growth.
- New leaves and flowers continue growing, but they wither before opening.
- Leaf edges develop irregularities and frequently show signs of scorching
- The whole plant becomes stunted and then dies.
Management
- Analysis of soil.
- Check the pH of the soil. If the soil is extremely acidic (pH between 3.5 and 4.5), apply lime at the rate of 3.4 kg/cent in two split doses. And in areas of moderate acidity (pH between 5.5 and 6), apply lime at the rate of 1 kg/cent.
- High phosphorus levels lead to calcium deficiency.
- In alkaline soil application of Gypsum is preferable
- Boron is needed for calcium utilization.
- So, a boron deficiency can also lead to calcium deficiency.
Magnesium (Mg)
Symptoms
- Symptoms are initially noticed on those leaves that are just beginning to attain their full size.
- Deficiency makes interveinal chlorosis in leaves as the veins remains green.
- Yellowing may lead to a whitish/bleached appearance on leaves
- Affected leaves may curl/distorted in appearance
- Leaf edges may appear wrinkled/serrated.
- Deficiency leads to slower growth & stunted plants.
- Slow emergence of new leaves.
- Severe deficiency causes leaf necrosis where Leaf tissue dies or brown/black.
- Affected leaves drop prematurely from plants.
- Lack of magnesium adversely affects floral production.
Management
- Do the soil analysis and confirm the deficiency.
- Addition of Magnesium sulphate (32 kg/ acre) in bands near plants.
- Long-term usage of dolomite will reduce magnesium deficiency
- Magnesium and potassium fertilizers should not be applied together
Sulphur(S)
Symptoms
- Symptoms appear on newly emerged leaves & progress to older leaves
- Symptoms are noticed on young leaves with less green colour.
- Entire plant turns yellow in colour.
- Slow growth of new leaves & reduced leaf size is noticed
- Delayed flowering & reduced flower quality
- Deficiency leads to smaller flowers with less vibrant blooms
- Leaves may appear thinner & more rigid compared to normal leaves
- Plants exhibit stunted growth
Management
- Application of sulphur-containing fertilisers, such as Factamfos, Ammonium sulphate, Single superphosphate, etc., reduces the deficiency.
- In sulphur deficient soils, apply sulphur dust (10 kg per acre).
- Deficiency in alkaline soil can be reduced by application of gypsum
- Addition of organic material improves sulphur availability in the soil.
- Burning of organic waste leads to sulphur deficiency
Boron (B)
Symptoms
- Symptoms noticed on younger leaves with developing tips
- Development of distorted & thickened leaves
- Leaf tips may die back
- Leaves may appear puckered or wrinkled
- Production of fewer or smaller flowers and blooms having distorted shape
- Development of brown spots or necrotic areas on leaf margins or in between the veins of leaves.
- Reduced root growth leads to stunted growth and reduced branching.
Management
- Analysis of soil to confirm the deficiency.
- Application of borax (4 kg/ acre) into the soil
- Addition of borax (1 gram / litre of water) as foliar spray.
- Avoid the combined application of Boron and calcium.
- Application of borax with ammonium fertilizers should be avoided.
Copper (Cu)
Symptoms
- Affected leaves exhibit mottled or chlorotic patterns of discoloration with yellowing or pale green colour
- Leaf malformation & curling with irregular edges
- Plants appear smaller in leaves with slow growth of newer leaves.
- Flowers are small, deformed & fail to develop
- Plants expressed delayed flowering
Management
- Apply copper sulphate (800 gram/acre) in the soil
Iron (Fe)
Symptoms
- Chlorosis of new leaves
- Symptoms started from new growth & progress to older leaves
- Younger leaves remain green in colour
- Interveinal chlorosis in the young leaves is noticed
- Mottled or striped appearances are seen on leaves
- Necrosis usually starts from the margin edges of leaves & progresses inwards
- In severe deficiency, plants exhibit stunting growth
Management
- Iron content in Kerala soils is often high. So, get a soil test to determine the reason for the deficiency
- Low potassium levels lead to iron deficiency
- Addition of Ferrous Sulphate (6 kg/ acre) into the deficient soils.
Manganese (Mn)
Symptoms
- Plant exhibits Interveinal chlorosis with the veins themselves remaining green
- Similar to iron deficiency, but chlorosis is more prominent in veins
- Reduced leaf size
- Leaves are distorted & deformed in irregular shape
- Necrotic spots turning brown or black in colour
- Usually leaf margins progress inwards
- Delayed flowering
- Deficiency is generally noticed in black soils and poorly drained soils
Management
- Soil Analysis
- Application of Manganese Sulphate (5 gram per litre of water) as foliar spray
Zinc (Zn)
Symptoms
- Symptoms commonly noticed in new leaves progress to older leaves.
- Interveinal chlorosis of leaves with green midribs and veins.
- Smaller leaves with distortion, cupping & twisted are seen
- Stunted growth of plant is observed
- Necrosis & browning of leaf tips are occasionally noticed
- Reduced flowering.
- Deficiency causes the rosette appearance of twigs.
- Leaf twigs may undergo dieback
Management
- The optimal pH range for zinc availability is 5 to 7.5.
- Confirm deficiencies by doing soil testing.
- Apply zinc sulphate to deficient soils (8 kg/ acre)
- Avoid the application of zinc and phosphate fertilizers at the same time
- In severe cases, foliar spraying of Zinc sulphate (2 gram/litre of water) with Calcium carbonate (2.5 gram/litre of water) can be advocated in morning hours.
