| 摘要 |
A machine distributable gypsum-based pesticide pellet in which the gypsum is a solid formed by the bonding of plaster of paris and water which includes, prior to formation of the solid, by weight, no more than the minimum water required for substantial hydration of the plaster of paris. The pellet includes approximately five percent of a pesticide with the balance being plaster of paris. The pesticide, water and plaster of paris are generally uniformly mixed to provide a pellet which has a generally uniform release of the pesticide over its life. The pellet after setting has essentially no free water in that substantially all water is absorbed in the chemical reaction between the plaster of paris and water. The pellet has a maximum surface area of about 180 mm2, a maximum weight of about 0.3 gram, and has been compressed in the extrusion process to eliminate porosity and external and internal voids.
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