Automatic samplers for elevator belts with one to four rows of cups can be obtained that operate on the same motor but open alternately.

IRRADIATION of seeds as a practical method for inspection can be done with compact X-ray equipment adapted to grain inspection. It requires little technical skill and a minimum of preparation of the sample. Other methods used in grain inspection require considerable time of highly trained personnel, and test results often are inconclusive.

Radiographs of grain samples for inspection are easily interpreted and give rapid results on the degree of internal infestations of insects. They can also be used to determine the amount of checking in rice, the effectiveness of fumigations, and the selection of grain for processing.

Irradiation of seed is the treating of seed electrically to increase its water absorption and reduce the count of hard seeds.

Irradiation is accomplished experimentally in two ways.

One is to place seeds in an evacuated glass tube and to apply about 1,000 volts to electrodes on the tube ends, so that there is a 10- to 50-milliampere current flow. The current flow causes gases in the tube to glow and act on the seeds. This is called a glow discharge treatment.

The other method is to subject the seeds to high frequencies using radio-frequency equipment.

An irradiated cotton seed, placed in water, sinks within a few seconds. A non-irradiated cotton seed will float 24 hours or longer before it absorbs enough water to sink.

Irradiation tests of seeds of alfalfa, corn, cotton, and red clover indicate that the treatment speeds up their water absorption, reduces the count of hard seed, and improves germination.

Irradiation tests offer some possibilities for sterilization. A mixture of turnip, red clover, and mustard seeds was treated. The germination of the turnip seeds was destroyed, but the germination of the red clover and mustard was apparently normal.

BLENDING seeds of a single variety may compensate for variations in germination, purity, and appearance,which are due to differences in soil fertility, weed infection, soil moisture, and time of harvesting.

This mixing process ordinarily is done after the seeds have been cleaned.

One method is to use several tanks, which are filled successively. The tanks are opened simultaneously into another tank or elevator. The operation is repeated until the desired uniformity is obtained.

To blend several lots of different purity or germination to any desired purity or germination, each lot is first blended to uniformity within itself and placed in a tank. The bottom of each tank is opened enough to meter out the desired amount of seeds that is needed in the finished product. The seeds from the various tanks can be discharged in a screw conveyor or similar device for thorough mixing.

Batch-type mixers are used for blending small lots. The vertical screw type, which was developed for mixing feed, is used in small seed-cleaning plants. Manufacturers have made improvements for cleaning and inspection.

Drum-type mixers tumble the seeds until they are mixed. Another type has a stationary drum, which has revolving paddles inside for mixing the seeds. The batch-type mixers are good for blending within a given batch. When several batches are to be blended, the work should be supervised so as to get all the batches uniform.

Pelleting has been tried with many kinds of seeds with varied degrees of success. Equipment has ranged from cement mixers to pharmacists' pill-coating machines.

Pelleting can be done by compression and coating in a rotary drum.

In the compression machine, seeds are placed in a recess. A water-soluble paste is forced around them. The pellet is formed as the molds are moved together. This method reduces germination and retards emergence of seedlings.

The rotary drum has replaced it. Seeds are placed in a rotating drum and alternately mist-sprayed with a liquid binder and fogged with a dust.

Dust adheres to the moist seeds and forms a sphere when the seeds roll around in the drum. Repeating the spraying and dusting gives a uniform spherical-shaped pellet.

Pelleting regulates the size of seeds for precision planting by machine and by hand, reduces the amount of seeds required to plant, and cuts the work of thinning crops.

Nontoxic insecticides, fungicides, Inoculants, lime, coloring matter, animal and bird repellants, and fertilizer can be added to the coating. The pellet can be of a color so that birds and small animals cannot recognize the seed. It is said to be the first time man has consistently outwitted the crow. Pellets of flower seeds can be made of the same colors as the bloom to help gardeners arrange color patterns.

Pelletized seeds cost more and weigh two to five times more than ordinary seeds. In small seeds, in which pelleting seems most advantageous, a piece of inert matter may form a pellet without a seed, while some pellets may contain more than one seed.

More moisture is required to germinate pelleted seeds, since the pellets must be dissolved. Delayed and irregular emergence may occur if moisture is limited.

Some seeds that have been pelleted successfully are those of pepper, cauliflower, lettuce, cabbage, tomatoes, parsley, celery, carrots, onions, sugar-beets, table beets, melons, corn, legume, and some grasses.

Pelleting of small, irregular-shaped seeds is favored by vegetable producers because their uniform size makes them easier to plant by hand or with a precision planter.

Decortication and the development of the monogerm sugarbeet seeds have meant that pelleted seeds of sugarbeets are used only in trial plantings.

SEEDS in plastic rolls and tapes are new. Grass, vegetable, and flower seeds have been used in them.

The seeds are metered at the desired rate on a water-soluble plastic tape or fibrous mat, which is coated with water-soluble adhesive that holds the seeds in position. The planting area is worked to form a good seedbed, and on it the tape is unrolled with the seeds down. Rain or irrigation water dissolves the adhesive. The seeds are uniformly distributed over the planted area. The tape reduces soil erosion, movement of the seeds by water and wind, and the loss of moisture through evaporation. It shades the tender sprout from the sun. The tape is a mulch as it dissolves.

Seeds of turf grass are embedded in rolls 24, 30, and 36 inches wide. The 3o-inch width seems easiest to handle.

The tape is useful particularly on steep banks and highway shoulders, where seeds are not easily held. Mixtures of lawn seeds can be metered by machines on a tape to give a uniform mixture in a lawn.

Flower seeds are placed on narrow tapes and wound on a plastic reel, like transparent household tape. The tape is unrolled and cut to the desired length for planting. With the seeds down, it is placed in a trench and covered with a thin layer of soil. Some flower seeds can be purchased on tapes three-eighths of an inch wide and of different lengths.

Seeds also are glued to paper grids and fibrous mats. Mixtures of turf seeds treated with disinfectant can be purchased on fiber mats in rolls that measure 100 to 5,000 square feet.

Flower seeds are also placed in fibrous mats or bats, which are called "roll-out-gardens." Some cut-flower or dwarf edging mixtures are available in mats that are 1/8 inch thick, 8 inches wide, and 144 inches long. The mat is unrolled on top of a loose seedbed and covered with a one-fourth-inch layer of topsoil and then watered. Cut-flower mats are available with seeds of asters, babysbreath, larkspur, marigolds, petunias, snapdragons, and zinnias. Dwarf edging mats contain sweet alyssum, poppies, marigolds, petunias, mignonette, and portulaca.

Small, plastic-covered cartons are available in which seeds have been placed in vermiculite. Holes are punched in the recesses of the plastic cover of the carton, and it is watered. After 24 hours, the cover is removed, and the vermiculite is kept moist. When plants emerge, they may be thinned. The carton can be used as a window box, or the plants can be transplanted. Flower and vegetable seeds are planted in the cartons; aster, carnations, dahlia, pansy, petunia, tomato, pepper, and others.

Inoculants, insecticides, pesticides, and fertilizer can be placed on the mat or tape along with the seeds to simplify gardening. Color is added to the mat or tape so it will absorb or reflect heat.

ANOTHER PROCESS is the adding of bacteria of the Rhizobia species to seeds of legumes to help them convert atmospheric nitrogen into protein and transfer nitrogen from air to soil. The bacteria encourage the formation of nodules on the roots. Nitrogen is stored in nodules and used by the plant as needed. Not all soils contain the correct kind of bacteria.

It has long been a practice to add bacteria to a new field or inoculate seeds to be planted. Specific bacteria can be purchased commercially for use on specific groups of seed the alfalfa, clover, soybean, pea and vetch, cowpea, bean, and lupine and serradella groups.

Birdsfoot trefoil, big trefoil, Dallas or "Wood's" clover, black locust, crownvetch, foxtail dalea, hemp, sesbania, lead plant, trailing wild bean, and Siberian peashrubs need specific strains of bacteria.

Seed inoculation often is done on the farm, usually on the day before seeding. The seeds and inoculant may be mixed in a bucket or tub. Large amounts can be mixed in the back of a truck. Small concrete mixers have also been used to mix large amounts.

Various binders and carriers such as powdered skim milk, sirup, and finely ground peat have been used in mixing.

THE SLURRY seed treater is suitable for applying the seed inoculant, but it can handle only small lots of seeds at a time and it must be cleaned thoroughly before it is used for inoculating seeds.

For certain legumes, the inoculant is placed in the seedbed at the time of planting. Inoculants mixed with a granular carrier can be applied with the fertilizer attachment on the planter. If it is in a liquid carrier, the inoculant is placed in the plow furrow with an attachment for applying liquid fertilizer.

Alfalfa seeds treated commercially can be held from one planting season to the next before the bacteria lose viability. In this new process, bacteria in water are applied to the alfalfa seeds in a seed treater. Air is removed from the coated seeds in a vacuum. Bacteria are forced under the seedcoats when the vacuum is released.