Nutrient Deficiencies of Bacopa 'Penny Candy Violet'

By Paul V. Nelson, John M. Dole, Dharmalingam S. Pitchay, James L. Gibson, Brian E. Whipker, Bobby Walls, and Brenda Cleveland

Fertility monitoring and management for bacopa requires a balancing of the plants needs. Growers must be aware and manage the root substrate pH, electrical conductivity (EC), and provide adequate, but not excessive, levels of all the essential elements for bacopa.

Nutrient deficiency descriptions are unavailable for most floriculture crops, yet growers must often make quick diagnoses. A research project initiated at NCSU in Raleigh documented deficiency symptoms in bacopa to assist growers. Using a plant diagnostic lab to identify the source of problems is still the best way to ensure accurate diagnoses, since many nutritional, physiological, insect and disease problems can mimic each other.

Disclainer: Growers should read and follow all label directions. Test the corrective procedure on a small number of plants prior to applying it to the entire crop.

Macronutrients · Micronutrients

Macronutrients
Photograph
Description
Possible Causes and Management
Nitrogen (N) (top)
Click for Larger Image Lighter-green lower leaves are the initial nitrogen deficiency symptom. Symptoms progress quickly up the plant, with the lower leaves yellowing rapidly. Deficient plants are smaller with less branching.
Low Substrate Nitrogen
Click for Larger Image Upper surfaces of older leaves become light green, while lower surfaces turn purple. Overall the plant growth of nitrogen deficient plants are stunted and the leaf size is also reduced.
Click for Larger Image As deficiency symptoms progress, the lower leaves become bright yellow, which later advances to necrosis on the older lower leaves.
Phosphorus (P) (top)
Click for Larger Image
Deficient plants initially have dark green upper leaves and poor lateral shoot development, as compared to the control.
Low Substrate Phosphorus
Click for Larger Image The leaf canopy is poorly developed due to limited secondary or tertiary branching.
Click for Larger Image Advanced symptoms appear as a pale-yellow coloration on the lower mature leaflets of deficient plants. Axillary shoot tips remain dark green. Unlike typical symptoms with many crops, purpling of the lower leaves was not observed.
Potassium (K) (top)
Click for Larger Image
Initially, potassium-deficient plants have upper leaves that are darker green in color, when compared to the control. Plants also have less axillary branching, but the stunting is not as severe as to what was observed with phosphorus.
Low Substrate Potassium
Click for Larger Image A more definitive symptom of potassium deficiency is the appearance of black speckles which quickly turn into brown necrotic spots on the older leaves.
Click for Larger Image The necrotic spots later coalesce into large tan patches on the mature leaves.
Calcium (Ca) (top)
Click for Larger Image A comparison of the control (L) and minus calcium (R) plants. Calcium deficient plants are smaller in size, have less branching, and have darker green leaves
Low Substrate Calcium
Click for Larger Image The younger leaves develop a yellowish-green coloration, while the mature leaves remain green. Shoot tips become completely scorched.
Click for Larger Image A closer view of axillary and shoot tip scorching, the typical symptoms associated with calcium deficiency.
Magnesium (Mg) (top)
Click for Larger Image Magnesium deficiency symptoms begin as tan-gray, papery, necrotic patches along the leaflet margins.
Low Substrate Magnesium
Click for Larger Image As symptoms advance, entire mature leaves become necrotic and leaflets shrivel rapidly.
Sulfur (S) (top)
Click for Larger Image Sulfur deficiency is first observed as uniformly yellow shoot tips, while the remaining leaves stay dark green.
Low Substrate Sulfur
Click for Larger Image As symptoms advance, the entire shoot turns yellowish-green.
Click for Larger Image The youngest leaves are bright yellow and develop an inward rolling. Some leaves wither and later become necrotic.
Micronutrients (top)
Photograph
Description
Possible Causes and Management
Boron (B) (top)
Click for Larger Image Plant growth is stunted with boron deficient plants. Flower development does not occur and leaf size is reduced by 80%, when compared to the control.
Low Substrate Boron
Click for Larger Image With boron deficiency, leaves become thick and the shoots are rigid.
Click for Larger Image Mature leaflets develop a chlorosis within the entire leaf blade.
Copper (Cu) (top)
Click for Larger Image The initial symptom of copper deficiency appears as deep green mature leaves, which lack a glossy appearance.
Low Substrate Copper
Click for Larger Image As deficiency symptoms progress, the mature leaves turn a paler green, while the axillary shoot tips become chlorotic.
Click for Larger Image Below the shoot apex, petioles of recently mature leaves rapidly shrivel, causing the entire leaf to wither.
Click for Larger Image A closer view of leaf necrosis.
Iron (Fe) (top)
Click for Larger Image Initial symptoms develop as a complete chlorosis of the shoot tips.
Low Substrate Iron
Click for Larger Image As deficiency symptoms progress, young leaflet tips develop a bleach-white appearance, which ultimately become necrotic.

Manganese (Mn) (top)
Click for Larger Image With initial symptoms of manganese deficiency, almost the entire plant, except for the older leaves, develops an uniform yellowish-green chlorosis.
Low Substrate Manganese
Click for Larger Image As symptoms progress, the recently matured leaves develop a distinct interveinal chlorosis.
Zinc (Zn) (top)
Click for Larger Image The initial symptom is a chlorosis of the oldest leaves along the main stems, while young leaves are still dark green.
Low Substrate Zinc
Click for Larger Image Symptoms then progress to a necrosis which slowly develops along the leaf margins and tips of the young leaves.
Click for Larger Image A close-up showing the overall leaf chlorosis and initial occurrence of marginal necrosis.

Dharmalingam S. Pitchay and James L. Gibson are graduate research assistants, Paul V. Nelson is professor in floriculture, John Dole is associate professor in floriculture, and Brian E. Whipker is assistant professor in floriculture at North Carolina State University, Department of Horticultural Science, Box 7609, Raleigh, NC 27695-7609. Bobby Walls and Brenda Cleveland are NCDA Agronomic Division Members NCDA&CS Agronomic Division, 4300 Reedy Creek Road Raleigh, NC 27607-6465. We would like to thank Paul Ecke Ranch, Encinitas, CA., Tom Abramowski, Rockwell Farms, Rockwell, N.C., and the North Carolina Commercial Flower Growers' for grant support, Paul Ecke Ranch for supplying the cuttings and Smithers-Oasis for supplying the propagation medium.

Disclainer: Growers should read and follow all label directions. Test the corrective procedure on a small number of plants prior to applying it to the entire crop.

© Copyright NC State University, 2002

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