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2000, No. 4
Symptoms of Common Nutrient Deficiencies
The University of Illinois hosted the annual North Central Region -192, a group of turfgrass researchers, educators, extension specialists and graduate students the last week of June at North Shore Country Club in Glenview, IL.
Thank you to Dan Dinelli, the maintenance staff and personnel at the club for providing accommodations that exceeded our needs.
As in years past, the group discussed current research being conducted at each university.
Representatives attended from Iowa State, Kansas State, Michigan State, Minnesota, Missouri, Nebraska, North Dakota State, Ohio State, South Dakota State, Southern Illinois, and Wisconsin.
Breeding and genetics, cultivar evaluations, soil fertility and plant nutrition, athletic turf, water, stress physiology, disease management, insect management, plant growth regulators, and weed management topics were discussed.
A topic that raised much interest was soil fertility and plant nutrition, especially nutrient deficiencies in turfgrasses.
It seems as though turf managers are applying more micronutrients and macronutrients across the region.
It was unsure how this trend started, and was surmised the pressure to apply these elements came from the sales side of the golf course industry.
There is no question that the turfgrass plant can suffer from nutrient deficiencies.
Nitrogen, phosphorus, potassium, iron, sulfur and manganese have been documented as elements that can become deficient in turf plants in our area.
As each specific nutrient becomes deficient, symptoms appear in the turfgrass plant.
Below is a listing of symptoms from common nutrient deficiencies:
- Nitrogen - Overall stunting of shoot growth, reduction in tillering and leaf length.
Older leaves turn pale green that changes to a yellow hue as the deficiency progresses towards the base of the blade.
- Phosphorus - Plants tend to become spindly and somewhat dwarfed, but not to the degree of a nitrogen deficiency.
Often accompanied by the dark green coloration of the lower older leaves, changing to a dull blue green with a purple discoloration appearing along the entire margin of the blade.
- Potassium - Leaf blades tend to droop and be horizontally inclined, as well as soft to the touch.
Excessive tillering of the plant is sometimes a symptom.
The older leaf tips and interveinal areas become yellow and the leaf tips will often times roll and wither.
In severe instances, the yellowing extends to the midvein, but remains green, though leaf margins are scorched and the tips severely withered.
- Sulfur - Similar to nitrogen deficiency, where older leaves become pale, often times yellow-green in color.
Unlike a nitrogen deficiency, a lack of sulfur will cause a faint scorching of the leaf tip that will advance toward the base of the blade in a thin line along each margin.
- Iron - Appears as the interveinal yellowing of the youngest, actively growing leaves.
Very similar to nitrogen deficiency, except it occurs on the youngest leaves of the plant, however it can spread to the older leaves if the conditions persist.
- Manganese - Similar to iron deficiency resulting in the interveinal yellowing of leaves, however, accompanied by small necrotic spots on affected leaves.
Veins tend to remain green as the leaves droop.
Several members of the NCR-192 group reported turf managers applying calcium to their turf to alleviate deficiencies.
Calcium is a macronutrient found in large quantities in the turfgrass plant, ranking third after nitrogen and potassium.
It is a constituent of cell walls, required for meristem growth by cell division, and a neutralizing agent for potentially toxic substances within the cell.
Symptoms of calcium deficiency in turf vary with the turf age, but overall symptoms on young plants include reddish-brown discoloration along the leaf margins, gradually extending to the midvein on younger leaves.
On older plants, symptoms appear as a reddish-brown discoloration of the interveinal leaf tissue, eventually fading to a lighter shade of red as the leaf tips become withered.
Interestingly enough, no member of the NCR-192 group has ever seen a calcium-deficient plant in the field.
Furthermore, the soils found in Illinois, especially our calcareous-sand based greens with high pH, provide much more than adequate amounts of calcium to the turf it supports.
As the rains continue across our state, plant nutrient availability should be monitored closely.
Available nitrogen can be lost quickly through plant growth, denitrification and leaching.
Managers should be on the lookout for disease development associated with low nitrogen levels in the turfgrass plant.
Outbreaks of dollar spot (Sclerotinia homoeocarpa), rust (Puccina spp.), red thread (Laetisaria fuciformis), and anthracnose (Colletotrichum graminicola) on Poa annua, can all be exacerbated by low levels of nitrogen and imbalanced fertility.
(Luke Cella and Tom Voigt)
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