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

Photograph	Description	Possible Causes and Management
Nitrogen (N) (top)
	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
	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.
	As deficiency symptoms progress, the lower leaves become bright yellow, which later advances to necrosis on the older lower leaves.
Phosphorus (P) (top)
	Deficient plants initially have dark green upper leaves and poor lateral shoot development, as compared to the control.	Low Substrate Phosphorus
	The leaf canopy is poorly developed due to limited secondary or tertiary branching.
	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)
	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
	A more definitive symptom of potassium deficiency is the appearance of black speckles which quickly turn into brown necrotic spots on the older leaves.
	The necrotic spots later coalesce into large tan patches on the mature leaves.
Calcium (Ca) (top)
	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
	The younger leaves develop a yellowish-green coloration, while the mature leaves remain green. Shoot tips become completely scorched.
	A closer view of axillary and shoot tip scorching, the typical symptoms associated with calcium deficiency.
Magnesium (Mg) (top)
	Magnesium deficiency symptoms begin as tan-gray, papery, necrotic patches along the leaflet margins.	Low Substrate Magnesium
	As symptoms advance, entire mature leaves become necrotic and leaflets shrivel rapidly.
Sulfur (S) (top)
	Sulfur deficiency is first observed as uniformly yellow shoot tips, while the remaining leaves stay dark green.	Low Substrate Sulfur
	As symptoms advance, the entire shoot turns yellowish-green.
	The youngest leaves are bright yellow and develop an inward rolling. Some leaves wither and later become necrotic.

Photograph	Description	Possible Causes and Management
Boron (B) (top)
	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
	With boron deficiency, leaves become thick and the shoots are rigid.
	Mature leaflets develop a chlorosis within the entire leaf blade.
Copper (Cu) (top)
	The initial symptom of copper deficiency appears as deep green mature leaves, which lack a glossy appearance.	Low Substrate Copper
	As deficiency symptoms progress, the mature leaves turn a paler green, while the axillary shoot tips become chlorotic.
	Below the shoot apex, petioles of recently mature leaves rapidly shrivel, causing the entire leaf to wither.
	A closer view of leaf necrosis.
Iron (Fe) (top)
	Initial symptoms develop as a complete chlorosis of the shoot tips.	Low Substrate Iron
	As deficiency symptoms progress, young leaflet tips develop a bleach-white appearance, which ultimately become necrotic.
Manganese (Mn) (top)
	With initial symptoms of manganese deficiency, almost the entire plant, except for the older leaves, develops an uniform yellowish-green chlorosis.	Low Substrate Manganese
	As symptoms progress, the recently matured leaves develop a distinct interveinal chlorosis.
Zinc (Zn) (top)
	The initial symptom is a chlorosis of the oldest leaves along the main stems, while young leaves are still dark green.	Low Substrate Zinc
	Symptoms then progress to a necrosis which slowly develops along the leaf margins and tips of the young leaves.
	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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