A granular particulate herbicidal composition having characteristics that permit it to be effectively applied to the ground aerially.

BACKGROUND OF THE INVENTION 
The invention relates to a granular particulate herbicidal composition with 
characteristics that permit the application effectively to forests and 
woodlands aerially with minimum drift. 
It is customary to formulate herbicides as water-dispersible compositions 
which can be readily mixed with water and applied by means of a spraying 
apparatus. An important class of herbicides which can be applied by this 
means comprises the symmetrical triazinediones, of which hexazinone, 
3-cyclohexyl-6-dimethylamino-1-methyl-s-triazine-2,4(1H,3H)-dione, is the 
most widely used. Formulations of this herbicide are marketed throughout 
the world as weed-killing compounds under the trade name Velpar.RTM. 
(trademark of E. I. du Pont de Nemours and Company, Wilmington, Delaware). 
One difficulty with aqueous herbicide formulations generally is that the 
active ingredient often has limited solubility in the water in which it is 
dispersed under the conditions of temperature at which the spraying is 
carried out. Heretofore, this has meant that the spray concentrations of 
many herbicides had to be limited to below their solubility limits in 
order to avoid crystallization within the spray apparatus and concomitant 
plugging of the spray nozzle. Nozzle plugging is most likely to take place 
when a crystal size of 150.mu. in any dimension is reached. Such plugging 
is of significant economic detriment for the reasons that (1) manpower 
time must be expended to discontinue spraying operations and remove the 
plugging material and (2) any area sprayed before the plugging is detected 
and corrected is likely to be covered inadequately. Hexazinone is one of 
those compounds which, because of its limited solubility in water, 
frequently incurs plugging when used at concentrations above its 
solubility limit at temperatures below about 37.degree. C. (98.6.degree. 
F.). For this reason, liquid spray herbicidal compositions containing 
hexazinone have been limited to concentrations of about 2-3% by weight of 
the active ingredient (hexazinone), unless they are heated to raise the 
solubility limit. Furthermore there is a tendancy for hexazinone to form 
insoluble trihydrate crystals in cold water even when the concentration is 
not saturated. 
The application of herbicides in granular particulate form does not incur 
the disadvantage of aqueous formulations provided they can be effectively 
applied. 
U.S. Pat. No. 4,172,714 discloses a dry compactible composition consisting 
of large pellets or balls, having a volume in the range of about 0.75 to 
2.0 cubic centimeters and containing 5 to 25% by weight of a herbicide 
which includes hexazinone which is useful for aerial application to 
woodlands. These pellets or balls are advantageous in that they can be 
produced by dry compaction, are impact and crush resistant while dry and 
are highly resistant to disintegration in high humidity atmospheres. 
Japanese publication No. 59-33201 discloses granules containing 3 to 16 wt 
% of antimicrobial agents and insecticides as active ingredients for 
aerial application which are characterized by (1) a particle size of 10-12 
mesh, (2) the number of granules per 1 g is 200-350, (3) the percent of 
particles in which the weight of 1 particle exceeds 5 mg is 10-30%, (4) 
the percent of particles in which the weight of 1 particle is 2 to 5 mg os 
50-85% and (5) the percent of particles in which the weight of 1 particle 
is less than 2 mg is 5-20%. 
U.S. Pat. No. 3,849,105 discloses a granular pesticide that can be applied 
aerially with minimized drift. There is however, no disclosure of the 
characteristics of the granules. The only disclosure is of 16 to 20 mesh 
particles of the carrier. 
Japanese Publication No. 48-1502 discloses an agrichemical granule 
formulation for aerial spreading by helicopter with a rest angle of 
35-50%. 
Applications which require the herbicide to be in the form of large pellets 
or balls or other particulate form cannot be effectively applied aerially 
because of (1) attrition of the particulates by the equipment used to 
discharge the particulates aerially, (2) drift of the particulates 
resulting in an ineffective application, and/or (3) inability to achieve 
control of vegetation. 
Where sufficiently large pellets have been used to eliminate drift from 
aerial applications ineffective biological control of undesired vegetation 
has resulted. Large pellets or balls may contain too much active 
ingredient causing injury to desired species or may take too long to break 
up to effect control of undesired vegetation or may provide inadequate 
density of ground coverage. Where pellets have met attrition requirements 
for aerial application the percent of active ingredient has been 
sufficiently low to make them less attractive economically for control of 
large areas, e.g., forest or woodlands. Low active ingredient requires 
reloading more times because of limited capacities of airplanes compared 
with high percent active ingredients. 
SUMMARY OF THE INVENTION 
Now herbicidal granular particulate formulations have been discovered for 
application to forests and wildlands and for industrial weed control with 
improved application efficiency for the control of undesired vegetation 
aerially. The granular particulate formulations comprise a herbicide at 
high concentrations that can be effectively used in forestry applications 
to control undesired vegetation. The effectiveness of the herbicide in 
forestry applications is improved by the rapid release of the herbicide 
from the granular particulate. Thus the granules will have release rates 
of 55 to 95% of the active ingredient in 4 minutes in the release rate 
test and thus will provide activity and will effectively control undesired 
vegetation with minimum rainfall. The granules rapidly disintegrate 
releasing herbicidal components with minimal rainfall. Applications can be 
made up to a height of 130 feet, giving a swath width up to 95 feet in up 
to 10 mph crosswinds. The herbicidal granular particulate formulations 
have characteristics which permit, when applied aerially, effective 
applications to the ground where the undesired vegetation is located, said 
characteristics comprising particulates wherein 95% to 100% by weight 
(preferably 96% to 100% and more preferably 98% to 100%) have a drop time 
of from 2 to 35 seconds (preferably 2 to 25 seconds) by the Drop Test and 
no more than 2% by weight attrition to particles that fall slower than 35 
seconds (preferably slower than 25 seconds) by the Drop Test. Attrition is 
measured by the Attrition Test and drop time by the Drop Test. The 
granular particulate formulations of the invention can be dispersed 
aerially without appreciable drift with the achievement of uniform 
distribution on the ground capable of controlling the growth of undesired 
vegetation to an acceptable degree. The granular particulates of the 
invention contain 50-99% by weight herbicide. 
More preferred granular particulates are those which have a drop time of 4 
to 20 seconds and no more than 2% attrition to particles falling slower 
than 25 seconds by the Drop Test. 
The herbicidal granular particulate compositions of the invention comprise 
50-99% by weight of a herbicide selected from hexazinone, mixtures of 
hexazinone with sulfometuron methyl, and agriculturally suitable salts of 
sulfometuron methyl with hexazinone wherein at least 95% of the granular 
particulates by weight have drop times of from 2 to 35 seconds in the Drop 
Test and attrition of less than 2% by weight to particles having a drop 
time greater than 35 seconds said composition having a release rate in 
water of 60-95% by weight of the herbicide in 4 minutes. 
Most preferred among the herbicides of the invention is hexazinone. However 
the granular particulates of the invention may comprise other herbicides. 
The granular particulate formulations of the invention allow consistent, 
predictable distribution with negligible wind drift, while economizing 
material used and further reducing the number of flights required because 
the payload contains dry active ingredients in high concentration. Liquid 
compositions have not only have added weight due to water but also are 
less concentrated. Other dry compositions are also less concentrated. 
The granular particulate of the invention can be made by first blending the 
powdered, preblended ingredients including the active herbicide. The 
blended ingredients are then hammermilled, reblended, airmilled to a 
herbicidally active particle size of 5-25 mm and optionally reblended 
again. This milled blend is then granulated on a pan (disc) granulator by 
spraying water onto the powder to form granules. The granules are then 
dried in a vibrating fluidized bed to produce the particulate of the 
invention. 
In order to ensure proper aerial applications with low drift, the granular 
particulates of the invention must have the following physical 
characteristics: 
Attrition: no greater than 2% by weight as determined by the Attrition Test 
Particle Drop Time: at least 95% by weight of the particles must drop in 
less than 35 seconds as determined by Drop Test 
Herbicidal Assay: 50-99% by weight of active herbicide 
Establishing the actual parameters of size, shape and density for a 
particulate of the invention that will result in an acceptable drop time, 
and therefore acceptable field performance, can be done several ways. 
Typically pan granulation is conducted once formulation ingredients are 
chosen. Pan granulation operation variables, such as depth, rotation speed 
and pan angle are selected which will produce a particulate with a 
characteristic shape and density. The formulation and the pan granulation 
variables are defined and then the particle size limits are established by 
sieving a crude pan-granulated product into several fractions of specific 
narrow mesh size ranges (such as -8/+10, -10/+12, -12/+14) and subjecting 
the granules from each screen to the Drop Test. At least 95% by weight of 
the granules must meet the drop time criteria (falling between 2 and 35 
seconds). This enables one to find the range of particle size that meets 
the drop time criteria. 
This procedure can be repeated until the full range of particle size is 
established for acceptable particulate. 
The release rate of the herbicide or active ingredient in the case of 
herbicidal applications is important to the effectiveness thereof. More 
specifically the rapid release of the active ingredient when the granule 
is exposed to moisture provides timely, effective biological control 
without undesirable delays that could otherwise lead to poor biological 
performance. The present herbicidal granular compositions release the 
active ingredient rapidly even under mild rainfall conditions. 
The granular compositions of the invention generally have release rates in 
water of 55-95% by weight of the herbicide or the active ingredient in 4 
minutes. Preferably said release rate is 60-95%. 
RELEASE RATE TEST 
Add 800 milliliters.+-.11 milliliters of distilled or deionized water to a 
one liter pyrex beaker (4" I D., 15.25" High) and set the stainless steel 
stirring paddle (3".times.13/16") of an adjustable speed stirring motor 
1/2 inch from the bottom of the beaker and adjust speed to 40 RPM.+-.1 
RPM. Add 0.3600 grams.+-.0.02 grams (record exact weight) of the granular 
composition and start timing. At 4 minutes using a syringe draw 2 
milliliters of solution from 1" below the water surface near the paddle 
shaft. Transfer the sample to an analytical vial with an acrodisc filter. 
Assay the sample using the standard hexazinone assay method. 
DROP TEST 
The Drop Test is an efficient method for determining in the laboratory 
whether or not a particulate material will meet the deposition 
requirements for field application. The drop time is determined in a 
controlled environment and therefore not subject to the outside variations 
of nature. Drop time limits describing an acceptable product will vary 
according to type of application, terrain features, nature of surrounding 
vegetation, meteorological conditions, the height of the applying vehicle 
above the ground, and the severity of measures needed to control 
off-target drift of the herbicide. For particular application, such as 
aerial herbicide application to forestry, drop time limits can be 
established by testing placebo formulations in the field and correlating 
acceptable deposition on target with drop times. Once this drop time limit 
has been identified for a placebo or herbicidal particulate, it will hold 
true for any product applied in the same manner in that market. 
The times in the Drop Test define the general aerodynamic properties of our 
material, that is, the combined effect of particle size, bulk density, 
surface features, and shape. 
A 2000 mL graduated cylinder, 8 cm in diameter is marked as follows: 
(1) one line 5 cm from top rim 
(2) second line 12 cm below above mark 
(3) last line 25 cm below second mark 
Light paraffin oil (saybolt viscosity 125/135 @ 100.degree. F., density 
0.86-0.87 g/cc @ 25.degree. C.) is poured into the cylinder to a level 
equal to the top mark. From each portion to be tested 50 particles are 
randomly selected. One at a time, each particle is placed into the 
cylinder and allowed to drop 12 cm to reach terminal velocity. Timing 
begins as the granule passes the second mark and ends as it passes the 
last mark. 
The particulate of the invention must not have an average drop time greater 
than 35 seconds per 25 cm. 
ATTRITION TEST 
This test measures the amount of the granular particulate of the invention 
which when passed through a metering box during aerial application breaks 
down into dust and/or fine particles having drop times in excess of 35 
seconds. 
Before conducting this test, the Drop Test is used to determine the 
particle size range resulting in acceptable drop times. A sample to be 
evaluated is then screened through U.S. standard screens of sizes that 
reflect this particle size range until a refined sample weighing at least 
300 grams total on all screens is obtained. 
To subject the particulate to attrition conditions, the metering box 
depicted in FIGS. 1, 2 and 3 is employed. The blade and shaft assembly is 
rotated at 70 revolutions per minute as verified by using a Jaquet 
hand-held speed indicator. 
FIG. 1 is a schematic drawing of the hopper, motor and metering box used 
for the attrition test. FIG. 2 is a top view thereof and FIG. 3 is a cross 
section of FIG. 1 through line 3--3. 
Referring to FIG. 2, the hopper top opening has dimensions of length L 
equal 11 inches and width W equal 6 inches and the hopper side is at an 
angle .alpha. of 50.degree.. The bottom opening is 81/2 inches.times.1/2 
inch. 
Referring now to FIG. 3, a 300 gram sample is poured into the hopper of 
metering box 1. The sample passes across the rubber flap 3 that is 1/16 
inch thick through the counterclockwise rotating blade assembly 4 and is 
either carried by the blades through another cycle or forced out through 
the opening 5 in cylinder 6 onto a pretared catch tray 7. The cylinder 6 
has an I.D. Of 17/8" the blade clearance with the cylinder 6 is 1/4 inch. 
The shaft 8 and blade extend across the hopper 9 inches. The shaft has a 
diameter of 3/4 inches and each blade extension from the shaft is 5/16 
inch. When the entire sample has passed through the box the metered 
granules in the catch tray are weighed. The blades subject the particulate 
to a certain degree of stress or attrition. 
Then the metered granules are brushed onto a stack of screens of varying 
mesh sizes, the largest mesh (smallest openings) giving drop times in 
excess of 35 seconds and the smallest mesh (largest openings) giving drop 
times less than 2 seconds and a catch pan. The stack is shaken, and the 
weight of undersized particulate collected in the catch pan is determined. 
The percent attrition to particles having drop times above 35 seconds that 
pass through the smallest openings into the catch pan is calculated by use 
of the mathematical formula: 
##EQU1## 
For the hexazinone-containing spheroidal (shape factor 0.9) granules 
prepared in Formulation Examples 1-3 below, the acceptable drop time range 
as determined by the Drop Test was found to correspond to particle sizes 
of U.S. 6-14# (particles that remain on screens of a mesh from 6 to 14). 
(For a description of "shape factor" see T. Allen, Particle Size 
Measurement, 3rd Ed., Chapman and Hall, New York, 1981, p. 110.) Granules 
of these Examples smaller than U.S. 14# fell too slowly (drop times&gt;35 s) 
in the Drop Test. The desired product cut (in this case, U.S. 6-14#) was 
obtained by prescreening on a Gilson Sieve Tester #SS-15 for 5 minutes and 
then subjected to the Attrition Test as described above. A U.S. 14# screen 
was used in the final screen-catch pan assembly. The % Attrition as 
calculated by use of the formula above is recorded in Table 2. 
HERBICIDAL ASSAY 
The amount of hexazinone in the granular particulate can be determined by 
the method that follows. Other herbicidal assays can be determined by 
similar procedures. 
An acetonitrile solution of a granular sample of the herbicide of the 
invention, containing an internal standard, is separated by gas 
chromatography on an analytical column packed with Chromosorb WHP. The 
eluted compounds are detected and quantitated with a flame ionization 
detector and a digital integrator. A calibration curve (i.e. peak area 
ratio vs. concentration), prepared from standard hexazinone solutions, is 
used to determine the amount of hexazinone in the sample. 
This method will detect at least 0.8% hexazinone with a relative standard 
deviation of 1.2%. 
BULK DENSITY 
The loose bulk density is determined by filling a container of known volume 
with granules of the particulate in a standard fashion and then weighing 
the filled container. The bulk density is calculated from the weight of 
the material and the volume occupied.

The following examples of preparing granular particulates of the invention 
involve percentages by weight unless otherwise indicated: 
EXAMPLE 1 
(Formulation 1) 
The following powdered raw materials were charged to a ribbon blender: 
______________________________________ 
Lbs % 
______________________________________ 
technical hexazinone (98% purity) 
400 79.6 
lactose monohydrate 55.23 11.0 
diisopropylnaphthalene sulfonate, 
30.10 6.0 
sodium salt 
polyethoxylated dinonylphenol 
15.1 3.0 
(150 ethyleneoxide units) 
sodium stearate 1.15 0.3 
sodium alginate 0.5 0.1 
______________________________________ 
The ingredients were blended 15 min. and then auger-fed to a no. 2 DH 
hammermill without a screen for delumping and then reblended in another 
ribbon blender. This blend was then fed to a 24 in. diameter air mill 
(ring pressure 80 psi, feed pressure, 25 psi) to yield a premix (average 
particle size 17 microns). This premix was auger-fed at 1000 lbs./hr. to a 
4.5 foot diameter pan (8 inches depth) for granulation under the following 
conditions: 50.degree. angle, 20 rpm, 81.1 lbs./hr. spray rate of water 
from two nozzles (L.sub.2 and L.sub.4 hollow cone type). The resulting 
damp granules (7.5% moisture) were conveyed to a vibrating dryer with 
fluidized air (1/16 in. wire-type deck with 0.006 in. opening, 10% free 
area, 54 sq. ft. total deck area). The dryer was equipped with 4 in. 
height weirs where the inlet air temperature to the three zones was 
120.degree.-140.degree. F. (49.degree.- 60.degree. C.) and the air 
velocity through the deck was 300 ft./min. The emerging partially dried 
granules (3% moisture) were passed a second time at a rate of 1000 
lbs./hr. through a similar dryer and sieved through a stack of vibrating 
screens to give final semi-spherical product with the properties listed in 
Table 2 (samples A and B were taken at two different times from the above 
continuous production run). 
EXAMPLES 2 AND 3 
The following formulations were prepared following the procedure in Example 
1. 
EXAMPLE 2 
78% technical hexazinone 
14.8% lactose 
4.0% sodium diisopropyl napthalene sulfonate 
0.1% sodium stearate 
0.1% sodium alginate 
3% polyethoxylated dinonylphenol 
EXAMPLE 3 
78% technical hexazinone 
14.8% Barden clay 
3.0% sodium dialkyl napthalene sulfonate (Daxad.RTM. 11G) 
4.0% sodium diisopropyl napthalene sulfonate 
0.1% sodium stearate 
0.1% sodium alginate 
The physical characteristics of the formulations are shown in Table 2. 
TABLE 2 
______________________________________ 
Physica1 Characteristics of Examples 1 to 3 
Example 
1 Example Example 
A B 2 3 
______________________________________ 
% Hexazinone 77.4 76.6 77.0 77.1 
% Moisture 1.3 2.2 2.5 1.5 
Lb/Ft.sup.3 Bulk Density 
35.61 39.6 40.0 40.0 
Avg. Drop Time/Sec 
13 13 13 14 
% Attrition 0.7 0.7 0.1 0.2 
(wt % of particles 
with a drop 
time greater 
than 35 sec.) 
______________________________________ 
In the formulations of the invention in Examples 1-3, lactose functions as 
a water soluble binder/diluent and helps rapid release into the soil of 
the hexazinone herbicide even during low rainfall and allows the 
formulation to also be used like a conventional dry flowable when mixed 
with water and sprayed. Barden Clay is a diluent and anticaker which 
promotes high density for antidrift during aerial application. Sodium 
diisopropyl napthalene sulfonate is a wetting agent, cobinder, and crystal 
growth inhibitor which prevents attrition during aging and which prevents 
nozzle plugging during aqueous applications. Sodium alginate is a binding 
agent. Daxad.RTM. 11G (sodium dialkyl naphthalene sulfonate) and 
polyethoxylated dinonyl phenol functions as cobinders/dispersing agents. 
Sodium stearate is an antifoam for aqueous application. 
For treating large areas where the terrain is difficult to reach, aerial 
applications are the preferred method of applying herbicides. Aerial 
applications are done at sufficient height above the terrain to avoid 
obstacles. Specific physical and chemical properties are important in 
assuring predictably accurate and thus safe and efficacious results. Above 
and beyond having the requisite biological activity, choosing the proper 
product parameters not only assures the before-mentioned results but also 
increases productivity. 
Known granular products or liquid products possess low strength and their 
carriers (such as water) create a major inconvenience due to the weight 
thereof and are a large cost component of herbicide application. 
In addition with respect to liquid applications, it is difficult to control 
the fine droplets formed as the liquid is released. The released liquid 
can move off the intended target and cause unwanted damage. Current 
nonaerial application methods with dry (granule) spreaders can cause 
attrition or "breaking up" of the dry materials producing small particles 
which can have as much potential to cause off-target damage as liquid 
applications and result in a lack of uniform distribution. Lack of uniform 
distribution can lead to damage to desirable vegetation or lack of control 
of undesirable vegetation due to irregularities in product rates on the 
ground. 
The granules of the present invention, although advantageously applied in 
granular form, can be applied by aqueous spraying. The granular 
particulate of the invention is readily dispersible in water. 
There are three key variables to control to get the desired aerodynamic 
behavior from particles: shape, density, and size. It is a combination of 
all three factors, not each singly that is important. This invention is 
directed to granular particulate herbicidal compositions with a 
combination of properties which permit the granule to be bound together, 
to be of high enough active strength to be economically viable to the 
grower, and to be makable in a shape compatible with the density, in a 
size to get it away from aircraft wake, and of ingredients having 
characteristics that give a size, attrition resistance, water solubility 
and active content per particle that is biologically desirable. 
The wake of an aircraft flying between 60 and 100 mph, speeds which are 
typical for agricultural applications by helicopters and fixed wing 
aircraft, greatly affects the particle parameters needed to maximize 
deposition on target and get a uniform application across the desired 
swath width. Particles which do not have the requisite combination of 
density, size and surface uniformity or relative sphericity can get caught 
in the aircraft wake or in the wind and be thrown off target, or at a 
minimum, lead to a non-uniform pattern. 
To some extent, adjustments can be made in the positioning of the discharge 
points of the particles on the aircraft to get them out of the wake. 
However, other considerations, such as pilot safety, and environmental 
conditions such as winds may make the necessary changes impractical or 
impossible. 
The simple Drop Test of this invention quickly leads to identification of 
particles which have the requisite combination of physical parameters when 
applied from aircraft to give deposition on target and a uniform swath 
from equipment which is easy for the pilot to use. This test works for 
formulations of hexazinone and also for any other agricultural formulation 
which would not be solubilized by the paraffin oil. It eliminates the need 
to field test a number of prototype formulations, which is very expensive 
and inefficient to do. The test does not measure size, density or shape 
alone, but the interaction of all three on a particle. It involves 
dropping individual particles into a specific liquid and measuring the 
time to travel a specified interval once terminal velocity in the liquid 
is achieved. Particles of different size, but common density and shape 
behave differently. Particles of different density, but common size and 
shape behave differently. Any particles of different shape, but similar 
size and density, also are differentiated. These observations in the 
laboratory test substantiate findings in actual field studies. As a 
result, it is possible to predict whether a particle will behave 
satisfactorily when discharged from an aircraft simply by observing 
whether it has an acceptable drop time in the liquid. 
The importance of particle aerodynamics in formulating materials for aerial 
applications in forestry, wildlands and for industrial weed control can be 
seen in Tables 3 through 6. The tables demonstrate how particle 
aerodynamics, as expressed by drop times from the Drop Test are influenced 
by all three components of size, shape, and density. 
In Table 3 four sample materials of varying bulk densities (lb/ft.sup.3) 
available commercially are listed with their corresponding times from the 
Drop Test. The particles measured were all of the same spherical shape 
factor of 0.90 and of the same size (-14/+16 mesh). As particle density 
increases so does the speed at which the particles fall. 
TABLE 3 
______________________________________ 
The drop times of spherical particles of uniform 
(-14/+16 mesh) size vary with the bulk density. 
Bulk Density 
Drop Time 
Material (lb/ft.sup.3) 
seconds 
______________________________________ 
Molecular Sieves 
43. 15.0 
Spike 34.3 62.4 
Bladex 90 29. 73.8 
Aatrex 9-0 26. 82.8 
______________________________________ 
In Table 4 the shape of particles can be seen to influence the rate of fall 
in the Drop Test. In this table all particles were constructed from the 
same homogeneous clay material and are of equal weight per particle (0.200 
g). All the shapes were designed to pass through a 28 mm opening. The drop 
times show that particle shape can influence the aerodynamics (expressed 
as drop time) of particles with a spherical shape having the most rapid 
descent and a flake having the slowest descent. 
TABLE 4 
______________________________________ 
Effects of changing shape on drop time when mesh size 
(28 mm) and weight (0.200 g) are kept constant. 
Shape (Avg) Drop Time (sec) 
______________________________________ 
Sphere 3.70 
Cube 4.04 
Triangular prism 4.31 
Cluster 4.29 
Cylinder 4.61 
Flake (rectangular plate) 
5.30 
______________________________________ 
Table 5 shows that particles made of a homogeneous formulation of 
hexazinone granules of the invention having a spheroidal shape (shape 
factor 0.90) and bulk density (38 lb/ft.sup.3) will exhibit increasing 
rates of fall in the drop test as their size is increased. 
TABLE 5 
______________________________________ 
Effects of changing size of particles on drop time 
when density (38 lb/ft.sup.3) and shape (spherical) are 
held constant. 
Hexazinone Granular Particulate 
Size (mesh) (Avg) Drop Time (sec) 
______________________________________ 
-6/+8 12.9 
-12/+14 32.6 
-20/+25 87.4 
-35/+40 279.5 
______________________________________ 
Table 6 shows that hexazinone particles of a given shape and density, with 
drop times greater than 35 seconds measured by the Drop Test are 
significantly displaced by wind, and thereby removed from targeted sites, 
creating the potential for unwanted herbicidal activity. Poor control of 
particle size, density and shape and thus the unpredictability of product 
placement also makes control of uniform distribution a problem. This lack 
of uniform distribution can be expressed in damage to desirable 
vegetation. The results are due to irregularities in product rates on the 
ground. All of these attributes of increased efficiency, uniform 
distribution, controlling pattern shape and minimizing off-target movement 
can be accomplished by controlling the combination product parameters that 
actually determine particle flight characteristics, namely: size, density, 
shape. Equally important are maintaining these desirable parameters 
throughout proper formulation, manufacturing, and application methods. The 
granular particulate of the invention defines those parameters for 
forestry, wildland and industrial weed control herbicides that will give 
effective herbicidal activity and maximize application efficiency. This 
approach differs from traditional herbicide designs which target 
formulation advantages but do not maximize use advantages. 
TABLE 6 
______________________________________ 
EFFECT OF VARYING TICLE SIZE 
ON TICLE DROP TIME AND TICLE RECOVERY 
WITHIN 150 FT OF RELEASE POINT 
(HEXAZINONE TICULATE) 
BULK % 
MESH SHAPE DENSITY DROP TEST 
RECOV- 
SIZE FACTOR (lb/cu ft) 
SECONDS ERY 
______________________________________ 
-7/+8 .90 36 16.7 95.06 
-10/+12 .90 36 31.3 99.62 
-12/+14 .90 36 41.25 91.7 
-20/+40 .90 36 279 51.0 
-40/+60 .90 36 &gt;350 0.0 
______________________________________ 
The particle parameters of the invention are based on requirements for 
aerial release from heights up to 130 feet above the terrain in crosswinds 
up to 10 mph. Granules with the parameters of the invention will when 
applied under the above stated conditions swaths of greater than 60 feet 
result in particulate distributions providing efficacious control of 
undesirable species. 
The particulate formulations have characteristics which permit, when 
applied aerially, effective applications to the ground of any particulate 
comprising any combination of size, density and surface uniformity or 
relative sphericity that will impart the proper particle aerodynamics 
permitting a drop time of 2 to 35 seconds by the Drop Test. Attrition must 
not cause more than 2% by weight of the particulate formulations of the 
instant invention to consist of particles having drop times in excess of 
35 seconds. 
Granular particulates with the characteristics disclosed herein were field 
tested using the Pattern Analysis System defined below. Products were 
flown, both in calm and windy conditions, into the wind and crosswind, to 
determine how the products which had acceptable flight characteristics 
related to those which did not. 
The Pattern Analysis equipment consists of collectors, balances and 
computer hardware-software. The collectors consist of 3 rows of 15 
collectors with an interval between collectors in a row of 10 feet. Each 
row is separated from the adjacent row by 20 feet. The collectors are made 
3 feet by 3 feet of lightweight ripstop nylon cloth on a rigid frame. In 
the Pattern Analysis System the nylon cloth absorbs the impact of the 
granules as they fall, thereby increasing the "capture" efficiency of the 
traps. The materials fall to the bottom of the traps and are captured in 
pre-marked (Location and Test I.D.) graduated tubes. 
The tubes are removed after each test and weighed on a gram balance. Each 
weight and location is entered into a computer where preprogrammed 
software statistically analyzes the data from each pattern, giving an 
accounht of deposited rate uniformity and/or variation across the pattern. 
The software also models the swath to analyze its possible operational 
results. 
During each test, environmental data on wind speeds and direction, 
temperature and relative humidity is recorded as well as the flight 
parameters and equipment configurations. True ground speed of the 
helicopter is indicated by measurement with a MPH radar gun. 
The relationship between drop time in the Drop Test and predictability of 
uniform deposition is important in aerial application, especially since 
those particles with fast drop times fall away from the wake influences of 
the aircraft and equipment faster. 
Once these physical characteristics were determined, biological trials 
confirmed that particles with the necessary parameters and having a 
concentrated amount of material per granule do effectively control 
undesirable species of plants on wildland sites. A hexazinone formulation 
of 75% active material with a drop time range in the Drop Test of 2-20 
seconds was aerially applied on 10 sites in the southern United States to 
determine biological efficacy of products with desirable flight 
characteristics. Operational flight methods were based on data acquired 
from field trials using the Du Pont Granular Pattern analysis system. 
The sites were chosen to give the widest representation of soil, topography 
and undesirable vegetation present on forestry sites. Each site consisted 
of plots 300 feet.times.400 feet separated by 50 feet plowed or pushed 
boundary lines surrounding each plot. Fifty specimens of the targeted pest 
species were tagged and numbered before the treatments. The plots were 
treated at a rate which represented the prescribed hexazinone rate for the 
soil type and species present for currently used liquid and overcoated 
dilute (10%) granules. The delivery equipment was calibrated and checked 
before each application, and an on-ground check was made at one site using 
the Pattern Analysis System to confirm accurate and uniform deposition as 
predicted in the pre-trial analysis. All applications were made by a Bell 
47B or 47G helicopter. 
The product was applied on all sites at a 130 foot release height while 
flying multiple swaths at 60 mph in back and forth manner at 95 foot 
widths centerline (under the aircraft) to centerline. For consistency, all 
tracts were flown in winds under 5 mph. The results shown in table 8 
confirmed that herbicidal activity can be maintained while addressing 
product physical parameters that optimize its aerial application use 
pattern. 
3 TABLE 8 
SUMMARY OF HEXAZINONE RESULTS ON NINE TESTS SITES % DEFOLIATION BY 
SPECIES HEXAZINONE APPLICATION RATE (LBS/ RED WHITE SWEET 
WINGED BLACK WINGED LOBIOLLY HERBACEOUS TREATMENTS ACRE) OAK OAK GUM 
ELM HICKORY DOGWOOD GUM SASSAFRAS SUMAC PINE CONTROL 
1. Evaluated 0 76 DAT.sup.1 Hexazinone 3.0 99 99 99 99 90 
99 99.3 -- -- 5 95 Hexazinone 3.5 99 99 99 99 16.7 88 94.5 -- -- 0 97.7 
2. Evaluated 87 DAT Hexazinone 3.0 88.3 -- 85 95 71.7 26.7 .75 -- -- 0 
78 Hexazinone 4.0 99.3 -- 99 99.5 99 99 20 -- -- 5 99.3 3. Evaluated 
89 DAT Hexazinone 3.0 96 95 87.5 99.7 -- -- 74.7 -- -- 0 68.3 
Hexazinone 3.5 97.7 94.7 96.3 99 45.0 85 32.5 -- -- 0 56.7 4. Evaluated 8 
6 DAT Hexazinone 3.0 98.3 99.7 94.7 100 41.7 90.0 87.5 -- -- 1.7 90.0 
Hexazinone 3.5 96.3 98.0 96.3 99.3 48.3 85.0 62.0 -- -- 4.3 81.7 5. 
Evaluated 86 DAT Hexazinone 3.0 98 99.3 99.3 -- 82 99.3 59.5 -- -- -- 
97.7 Hexazinone 4.0 100 100 100 -- 99 97.7 97.0 -- -- 0 90 6. Evaluated 
104 DAT Hexazinone 3.0 95 91 -- -- 80 88 -- 75 -- 1.0 -- Hexazinone 
4.0 95 96 -- -- 84 95 -- .75 -- 9.0 -- 7. Evaluated 94 DAT Hexazinone 
3.0 89 -- 74 -- 82 88 -- 97 100 5 -- Hexazinone 4.0 95 -- 89 -- -- -- 
-- 100 92 70 -- 8. Evaluated 110 DAT Hexazinone 3.0 96 98 -- 90 88 90 
-- -- -- -- -- Hexazinone 4.0 98 98 90 95 -- 96 -- -- -- -- -- 9. 
Evaluated 92 DAT Hexazinone 2.5 94 97 -- -- -- -- -- 84 -- -- -- 
Hexazinone 3.0 89 100 -- -- -- -- -- 90 -- -- -- 
.sup.1 DAT DAYS AFTER TREATMENT 
.sup.2 HERBACEOUS CONTROL GENERAL CONTROL OF FOREST SITE GROUND COVERS 
The dry particulate herbicidal composition of the invention can include one 
or more other biologically active compounds to form a multicomponent 
herbicide giving an even broader spectrum of effective agricultural 
protection. In particular, it may be advantageous to prepare the dry 
particulate with a combination of herbicides. 
Examples of other biologically active compounds that may be incorporated 
into the dry particulate with the active herbicides described above 
include: 
Bacillus thuringiensis 
Avermectin B 
______________________________________ 
Chemical Name 
______________________________________ 
Trade Name or 
Code Number 
DPX-L5300 2-[[N-(4-methoxy-6-methyl-1,3,5-tria- 
zine-2-yl)-N-methylaminocarbonyl]- 
aminosulfonyl]benzoic acid, methyl 
ester 
PPG-1013 5-(2-chloro-4-(trifluoromethyl)phenoxy)- 
2-nitroacetophenone oxime-O-acetic 
acid, methyl ester 
FMC 57020 2-(2'-chlorophenyl)methyl-4,4-dimethyl- 
3-isoxazolidinone 
AC 222,293 6-(4-isopropyl-4-methyl-5-oxo-2-imid- 
azolin-2-yl)- .sub.--m-toluic acid, methyl 
ester and 6-(4-isopropyl-4-methyl-5- 
oxo-2-imidazolin-2-yl- -p-toluic acid, 
methyl ester 
Common Name 
acifluorfen 
5-[2-chloro-4-(trifluoromethyl)phenoxy]- 
2-nitrobenzoic acid 
acrolein acrolein 
alachlor 2-chloro-2',6'-diethyl-N-(methoxymethyl)- 
acetanilide 
ametryn 2-(ethylamino)-4-(isopropy)amino)-6- 
methylthio)- .sub.-s-triazine 
amitrole 3-amino- .sub.-s-triazole 
AMS ammonium sulfamate 
asulam methyl sulfanilylcarbamate 
atrazine 2-chloro-4-(ethylamino)-6-(isopropyl- 
amino)- .sub.-s-triazine 
barban 4-chloro-2-butynyl .sub.--m-chlorocarbanilate 
benefin N-butyl-N-ethyl-.alpha.,.alpha.,.alpha.-trifluoro-2,6- 
dinitro- -p-toluidine 
bensulide O,O-diisopropyl phosphorodithioate 
S-ester with N-(2-mercaptoethyl)- 
benzenesulfonamide 
bentazon 3-isopropyl-1H-2,1,3-benzothiadiazin- 
4(3H)-one 2,2-dioxide 
benzipram 3,5-dimethyl-N-(1-methylethyl)-N- 
(phenylmethyl)benzamide 
benzoylprop 
N-benzoyl-N-(3,4-dichlorophenyl)-DL- 
alaine 
bifenox methyl 5-(2,4-dichlorophenoxy)-2- 
nitrobenzoate 
bromacil 5-bromo-3-sec-butyl-6-methyluracil 
bromoxynil 3,5-dibromo-4-hydroxybenzonitrile 
butachlor N-(butoxymethyl)-2-chloro-2',6'- 
diethylacetanilide 
butam 2,2-dimethyl-N-(1-methylethyl)-N- 
(phenylmethyl)propanamide 
buthidazole 
3-[5-(1,1-dimethylethyl)-1,3,4-thiadia- 
zol-2-yl]-4-hydroxy-1-methyl-2-imida- 
zolidinone 
butralin 4-(1,1-dimethylethyl)-N-(1-methyl- 
propyl)-2,6-dinitrobenzenamine 
butylate S-ethyl-diisobutylthiocarbamate 
cacodylic hydroxydimethylarsine oxide 
acid 
carbetamide 
D-N-ethyllactamide carbanilate (ester) 
CDAA N-N-diallyl-2-chloroacetamide 
CDEC 2-chloroallyl diethyldithiocarbamate 
chlorbromuron 
3-(4-bromo-3-chlorophenyl)-1-methoxy-1- 
methylurea 
chloroxuron 
3-[ -p-( -p-chlorophenoxy)phenyl]-1,1- 
dimethylurea 
chlorpropham 
isopropyl .sub.--m-chlorocarbanilate 
chlorsulfuron 
2-chloro-N-[(4-methoxy-6-methyl-1,3,5- 
triazin-2-yl)aminocarbonyl]benzene- 
sulfonamide 
chlortoluron 
N'-(3-chloro-4-methylphenyl-N',N'- 
dimethylurea 
cinmethylin 
exo-1-methyl-4-(1-methylethyl)-2-[(2- 
methylphenyl)methoxy]-7-oxabicyclo- 
[2.2.1]heptane 
cisanilide cis-2,5-dimethyl-N-phenyl-1-pyrrolidine- 
carboxamide 
CMA calcium methanearsonate 
cyanazine 2-[[4-chloro-6-(ethylamino)- .sub.-s-triazin-2- 
yl]amino]-2-methylpropionitrile 
cycloate S-ethyl N-ethylthiocyclohexanecarbamate 
cycluron 3-cyclooctyl-1,1-dimethylurea 
cyperquat 1-methyl-4-phenylpyridinium 
cyprazine 2-chloro-4-(cyclopropylamino)-6-(iso- 
propylamino)- .sub.-s-triazine 
cyprazole N-[5-(2-chloro-1,1-dimethylethyl)-1,3,4- 
thiadiazol-2-yl]cyclopropanecarbox- 
amide 
cypromid 3',4'-dichlorocyclopropanecarboxanilide 
dalapon 2,2-dichloropropionic acid 
dazomet tetrahydro-3,5-dimethyl-2H-1,3,5-thia- 
diazine-2-thione 
DCPA dimethyl tetrachloroterephthalate 
desmetryn 2-(isopropylamino)-4-(methylamino)-6- 
methylthio)- .sub.-s-triazine 
diallate S-(2,3-dichloroallyl)diisopropylthio- 
carbamate 
dicamba 3,6-dichloro- -o-anisic acid 
dichlobenil 
2,6-dichlorobenzonitrile 
dichlorprop 
2-(2,4-dichlorophenoxy)propionic acid 
diclofop 2-[4-(2,4-dichlorophenoxy)phenoxy]- 
propanoic acid 
diethatyl N-(chloroacetyl)-N-(2,6-diethylphenyl)- 
glycine 
difenzoquat 
1,2-dimethyl-3,5-diphenyl-1H-pyrazolium 
dinitramine 
N.sup.4,N.sup.4 -diethyl-.alpha.,.alpha.,.alpha.-trifluoro-3,5- 
1 
dinitrotoluene-2,4-diamine 
dinoseb 2-sec-butyl-4,6-dinitrophenol 
diphenamide 
N,N-dimethyl-2,2-diphenylacetamide 
dipropetryn 
2-(ethylthio)-4,6-bis(isopropylamino)- 
.sub.-s-triazine 
diquat 6,7-dihydrodipyrido[1,2-.alpha.:2',1'-c]- 
pyrazinediium ion 
diuron 3-(3,4-dichlorophenyl)-1,1-dimethylurea 
DSMA disodium methanearsonate 
endothall 7-oxabicyclo[2.2.1]heptane-2,3-dicarbox- 
ylic acid 
erbon 2-(2,4,5-trichlorophenoxy)ethyl 2,2- 
dichloropropionate 
ethafluralin 
N-ethyl-N-(2-methyl-2-propenyl)-2,6- 
dinitro-4-(trifluoromethyl)benzen- 
amine 
ethofumesate 
(.+-.)-2-ethoxy-2,3-dihydro-3,3-dimethyl- 
5-benzofuranyl methanesulfonate 
fenac (2,3,6-trichlorophenyl)acetic acid 
fenoxaprop ethyl 2-(4-(6-chloro-2-benzoxazolyl- 
ethyl oxy)phenoxy)propanoate 
fenuron 1,1-dimethyl-3-phenylurea 
fenuron TCA 
1,1-dimethyl-3-phenylurea mono(tri- 
chloroacetate) 
flamprop N-benzoyl-N-(3-chloro-4-fluorophenyl)- 
DL-alanine 
fluchloralin 
N-(2-chloroethyl)-2,6-dinitro-N-propyl- 
4-(trifluoromethyl)aniline 
fluometuron 
1,1-dimethyl-3-(.alpha.,.alpha.,.alpha.-trifluoro- .sub.--m-tol 
yl)- 
urea 
fluorodifen 
-p-nitrophenyl .alpha.,.alpha.,.alpha.-trifluoro-2-nitro- 
-p-tolyl ether 
fluridone 1-methyl-3-phenyl-5-[3-(trifluoro- 
methyl)phenyl]-4(1H)-pyridinone 
fomesafen 5-(2-chloro-4-trifluoromethylphenoxy)- 
N-methylsulfonyl-2-nitrobenzamide 
fosamine ethyl hydrogen (aminocarbonyl)phos- 
phonate 
glyphosate N-(phosphonomethyl)glycine 
haloxyfop 2-(4-(3-chloro-5-trifluoromethylpyridin- 
methyl 2-yloxy)phenoxy)propanoic acid, methyl 
ester 
hexaflurate 
potassium hexafluoroarsenate 
hexazinone 3-cyclohexyl-6-(dimethylamino)-1-methyl- 
1,3,5-triazine-2,4(1H,3H)-dione 
imazapyr 2-(4,5-dihydro-4-methyl-4-(1-methyl- 
ethyl)-5-oxo-1H-imidazol-2-yl]-3-pyri- 
dinecarboxylic acid and agriculturally 
suitable salts thereof such as 1:1 
with 2-propanamine 
imazaquin 2-(4,5-dihydro-4-methyl-4-(1-methyl- 
ethyl)-5-oxo-1H-imidazol-2-yl)-3- 
quinolinecarboxylic acid 
imazethapyr 
2-[4,5-dihydro-4-methyl-4-(1-methyl- 
ethyl)-5-oxo-1H-imidazol-2-yl]-5- 
ethyl-3-pyridinecarboxylic acid 
ioxynil 4-hydroxy-3,5-diiodobenzonitrile 
isopropalin 
2,6-dinitro-N,N-dipropylcumidine 
karbutilate 
tert-butylcarbamic acid ester with 3-( .sub.--m- 
hydroxyphenyl)-1,1-dimethylurea 
lactofen 1'-(carboethoxy)ethyl-5-(2-chloro-4- 
(trifluoromethyl)phenoxy)-2-nitro- 
benzoate 
lenacil 3-cyclohexyl-6,7-dihydro-1H-cyclopenta- 
pyrimidine-2,4(3H,5H)-dione 
linuron 3-(3,4-dichlorophenyl)-1-methoxy-1- 
methylurea 
MAA methanearsonic acid 
MAMA monoammonium methanearsonate 
MCPA [(4-chloro- -o-tolyl)oxy]acetic acid 
MCPB 4-[(4-chloro- -o-tolyl)oxy]butyric acid 
mecoprop 2-[(4-chloro- -o-tolyl)oxy]propionic acid 
mefluidide N-[(2,4-dimethyl-5-[[(trifluoromethyl)- 
sulfonyl]amino]phenyl]acetamide 
methal- N-(2-methyl-2-propenyl)-2,6-dinitro-N- 
propalin propyl-4-(trifluoromethyl)benzenamide 
methabenz- 1,3-dimethyl-3-(2-benzothiazolyl)urea 
thiazuron 
metham sodium methyldithiocarbamate 
methazole 2-(3,4-dichlorophenyl)-4-methyl-1,2,4- 
oxadiazolidine-3,5-dione 
methoxuron N'-(3-chloro-4-methoxyphenyl)N,N- 
dimethylurea 
metolachlor 
2-chloro-N-(2-ethyl-6-methylphenyl)-N- 
(2-methoxy-1-methylethyl)acetamide 
metribuzin 4-amino-6-tert-butyl-3-(methylthio)-as- 
triazine-5(4H)-one 
metsulfuron 
methyl 2-[[(4-methoxy-6-methyl-1,3,5- 
methyl triazine-2-yl)aminocarbonyl]amino- 
sulfonyl]benzoate 
molinate S-ethyl hexahydro-1H-azepine-1-carbo- 
thioate 
monolinuron 
3-( -p-chlorophenyl)-1-methoxy-1-methyl- 
urea 
monuron 3-( -p-chlorophenyl)-1,1-dimethylurea 
monuron TCA 
3-( -p-chlorophenyl)-1,1-dimethylurea 
mono(trichloroacetate) 
MSMA monosodium methanearsonate 
napropamide 
2-(.alpha.-naphthoxy)-N,N-diethylpropion- 
amide 
naptalam N-1-naphthylphthalamic acid 
neburon 1-butyl-3-(3,4-dichlorophenyl)-1-methyl- 
urea 
nitralin 4-(methylsulfonyl)-2,6-dinitro-N,N- 
dipropylaniline 
nitrofen 2,4-dichlorophenyl -p-nitrophenyl ether 
nitrofluorfen 
2-chloro-1-(4-nitrophenoxy)-4-(tri- 
fluoromethyl)benzene 
norea 3-(hexahydro-4,7-methanoindan-5-yl)-1,1- 
dimethylurea 
norflurazon 
4-chloro-5-(methylamino)-2-(.alpha.,.alpha.,.alpha.-tri- 
fluoro- .sub.--m-tolyl)-3(2H)-pyridazinone 
oryzalin 3,4-dinitro-N,N-dipropylsulfanilamide 
oxadiazon 2- .sub.--te .sub.--rt-butyl-4-dichloro-5-isopro- 
poxyphenyl).sup..DELTA.2 -1,3,4-oxadiazolin-5-one 
oxyfluorfen 
2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4- 
(trifluoromethyl)benzene 
paraquat 1,1'-dimethy 1-4,4'-bipyridinium ion 
PBA chlorinated benzoic acid 
pendimethalin 
N-(1-ethylpropyl)-3,4-dimethyl-2,6- 
dinitrobenzenamine 
perfluidone 
1,1,1-trifluoro-N-[2-methyl-4-(phenyl- 
sulfonyl)phenyl]methanesulfonamide 
picloram 4-amino-3,5,6-trichloropicolinic acid 
procyazine 2-[[4-chloro-6-(cyclopropylamino)-1,3,5- 
triazine-2-yl]amino]-2-methylpropane- 
nitrile 
profluralin 
N-(cyclopropylmethyl)-.alpha.,.alpha.,.alpha.-trifluoro- 
2,6-dinitro-N-propyl- -p-toluidine 
prometon 2,4-bis(isopropylamino)-6-methoxy- .sub.-s- 
triazine 
prometryn 2,4-bis(isopropylamino)-6-(methylthio)- 
.sub.-s-triazine 
pronamide 3,5-dichloro N-(1,1-dimethyl-2-propyn- 
yl)benzamide 
propachlor 2-chloro-N-isopropylacetanilide 
propanil 3',4'-dichloropropionalide 
propazine 2-chloro-4,6-bis(isopropylamino)- .sub.-s- 
triazine 
propham isopropyl carbanilate 
prosulfalin 
N-[[4-(dipropylamino)-3,5-dinitro- 
phenyl]sulfonyl]-S,S-dimethylsulfil- 
imine 
prynachlor 2-chloro-N-(1-methyl-2-propynyl)acet- 
anilide 
quinofop 2-[4-(6-chloroquinoxalin-2-yloxy)phen- 
ethyl oxypropanoic acid, ethyl ester 
secbumeton N-ethyl-6-methoxy-N'(1-methylpropyl)- 
1,3,5-triazine-2,4-diamine 
sethoxydim 2-[1-(ethoxyimino)butyl]-5-[2-(ethyl- 
thio)propyl]-3-hydroxy-2-cyclohexene- 
1-one 
siduron 1-(2-methylcyclohexyl)-3-phenylurea 
simazine 2-chloro-4,6-bis(ethylamino)- .sub.-s-triazine 
simetryn 2,4-bis(ethylamino)-6-(methylthio)- .sub.-s- 
triazine 
sulfometuron 
methyl 2-[[[[(4,6-dimethyl-2-pyri- 
methyl midinyl)amino]carbonyl]amino]sulfonyl] 
benzoate 
supriox 2-[1-(2,5-dimethylphenyl)ethylsulfonyl]- 
pyridine-N-oxide 
TCA trichloroacetic acid 
tebuthiuron 
N-[5-(1,1-dimethylethyl)-1,3,4-thiadi- 
azol-2-yl]-N,N'-dimethylurea 
terbacil 3-tert-butyl-5-chloro-6-methyluracil 
terbuchlor N-(butoxymethyl)-2-chloro-N-[2-(1,1- 
dimethylethyl)-6-methylphenyl]- 
acetamide 
terbuthyl- 2-(tert-butylamino)-4-chloro-6-(ethyl- 
azine amino)- .sub.-s-triazine 
terbutol 2,6-di-tert-butyl- -p-tolyl methylcar- 
bamate 
terbutryn 2-(tert)-4-(ethylamino)-6- 
(methylthio)- .sub.-s-triazine 
tetrafluron 
N,N-dimethyl-N'-[3-(1,1,2,2-tetrafluoro- 
ethoxy)phenyl]urea 
thiameturon 
3-[[(4-methoxy-6-methyl-1,3,5-triazin- 
methyl 2-yl)aminocarbonyl]aminosulfonyl]-2- 
thiophenecarboxylic acid, methyl ester 
thiobencarb 
S-[(4-chlorophenyl)methyl] diethylcar- 
bamothioate 
triallate S-(2,3,3-trichloroallyl)diisopropylthio- 
carbamate 
trifluralin 
.alpha.,.alpha.,.alpha.-trifluoro-2,6-dinitro-N,N-propyl- 
-p-toluidine 
trimeturon 1-( -p-chlorophenyl)-2,3,3-trimethylpseu- 
dourea 
vernolate S-propyl dipropylthiocarbamate 
ethyl 5-[2-chloro-4-(trifluoromethyl)- 
phenoxy]-2-nitrobenzoic acid 
2,3,6-TBA.sup.b 
2,3,6-trichlorobenzoic acid 
2,4-D (2,4-dichlorophenoxy)acetic acid 
2,4-DB 4-(2,4-dichlorophenoxy)butyric acid 
2,4-DEP tris[2-(2,4-dichlorophenoxy)ethyl] 
phosphite 
______________________________________ 
Agriculturally suitable salts of the above listed biologically active 
compounds may also be included in the dry particulate herbicidal 
composition of the invention. 
The granulate particulate formulations of this invention can significantly 
increase the efficiency of aerial applications of herbicides on forestry, 
wildlands, and industrial weed control sites. An example of that 
efficiency is the quantity of land that can be treated per load on a given 
aircraft. A Bell 206B helicopter, such as those commonly used in the 
applications of herbicides cited in this invention, can safely carry an 
average load of 500 lbs of material. A helicopter with one full load of 
conventional liquid product would contain enough material for treating 12 
acres. In applications of a low strength granule of 10% hexazinone such as 
those currently used in forestry, a Bell 206 can safely carry enough 
material to treat 17 acres per load. In field test of a high strength 
(75%) granule with the properties outlined in this invention, the same 
aircraft can carry enough material to treat 125 acres in one load. This 
considerable increase in efficiency translates to much more time applying 
product and less time loading and ferrying aircraft. The increased 
efficiencies of this invention have a considerable impact in reducing 
users' application cost.