EFFECT OF TWO RELATIVE HUMIDITIES ON FOLIAR ABSORPTION OF NaCl

White cedar (Thuja occidentalis L.) plants sprayed with deicing salt and kept at 91–100% relative humidity even for 1 day exhibited necrosis of foliage. However, sprayed trees kept at a relative humidity of 50–70% for 20 days showed only slight yellowing of leaf tips. Significantly greater amounts of Na and Cl ions were found in the foliage of plants maintained at high relative humidity.

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Root and Foliar Absorption of Atrazine Applied Postemergence to Broadleaf Weeds

Weed Science ◽

10.1017/s0043174500079959 ◽

1970 ◽

Vol 18 (3) ◽

pp. 349-351 ◽

Cited By ~ 5

Author(s):

Lafayette Thompson ◽

F. W. Slife

Keyword(s):

Relative Humidity ◽

Field Experiments ◽

Foliar Spray ◽

High Relative Humidity ◽

Growth Chamber ◽

Foliar Absorption ◽

Root Absorption

Results from both growth chamber and field experiments indicate that root absorption of 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine) applied postemergence to small broadleaf weeds is not a requisite for their control. Though broadleaf weeds absorb toxic quantities of atrazine from wet soil, they can be killed by foliar absorption alone because all of their meristems are exposed to a foliar spray. They are particularly sensitive when foliar penetration is enhanced by high relative humidity and wet foliage.

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Foliar Absorption and Translocation of Herbicides from Aqueous Solution and Treated Soil

Weed Science ◽

10.1017/s0043174500057350 ◽

1992 ◽

Vol 40 (2) ◽

pp. 281-287 ◽

Cited By ~ 18

Author(s):

Kassim Al-Khatib ◽

Robert Parker ◽

E. Patrick Fuerst

Keyword(s):

Aqueous Solution ◽

Relative Humidity ◽

Aqueous Solutions ◽

High Relative Humidity ◽

Crop Damage ◽

Foliar Uptake ◽

Multiple Exposure ◽

Foliar Absorption ◽

Treated Soil ◽

Plant Foliage

It has been suggested that soil treated with a herbicide and subsequently carried by wind and deposited on plant foliage can cause crop injury. This study compared foliar uptake and translocation of herbicides applied to plants as an aqueous solution or in herbicide-treated soil. Leaves of 3-wk-old seedling alfalfa, grape, and pea were treated with14C-labeled thifensulfuron, chlorsulfuron, glyphosate, 2,4-D, and bromoxynil. Significant amounts of all herbicides were absorbed by pea, alfalfa, and grape from the aqueous solutions, whereas very limited absorption occurred from herbicide-treated soil. Prolonged and multiple exposure to herbicide-treated soil did not increase herbicide uptake. High relative humidity enhanced herbicide absorption from aqueous solutions but not from herbicide-treated soil. All herbicides except bromoxynil were readily translocated in alfalfa, grape, and pea. Limited quantities of herbicides were absorbed from herbicide-treated soil by plant foliage, and this small amount is unlikely to cause crop damage.

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