Zinc
Zinc is important in early plant growth and in seed formation. It also plays a role in chlorophyll and carbohydrate production.
Identification
- Zinc is relatively immobile within the plant,
- Deficiency symptoms appear first on younger leaves,
- Young leaves become mottled and show interveinal chlorosis, striping or banding,
- In advanced stages in tree fruits, small, narrow terminal leaves are arranged in whorls or “rosettes”,
- This results in the typical “rosette” and “little leaf” description for zinc deficiency,
- Defoliation may occur early, starting with older leaves.
- herbicides such as triazines (simazine, atrazine); ureas (diuron, linuron), uracil (terbacil, bromacil); dichlobenil; gylphosate.
- sucking insects (aphids, leafhoppers, mites, plant bugs).
- alkaline soils or overliming may cause deficiency,
- soil pH > 7.0,
- soils high in natural phosphates or over applications of fertilizers high in phosphates reduce zinc absorption and translocation,
- may result on course sandy soils,
- liberal applications of nitrogen or high levels or iron may induce deficiency.
- may be induced by cool, wet spring weather,
- low soil temperatures
Often Confused With
Chemical:
Insects:
Soil & planting conditions:
Weather:
Scouting Notes
Zinc deficiencies are most often seen on sandy soils with high pH levels. Heavily eroded knolls may also have deficiency problems. Large applications of phosphorus may aggravate zinc deficiencies.
