Masters Theses

Date of Award

12-1964

Degree Type

Thesis

Degree Name

Master of Science

Major

Biosystems Engineering

Major Professor

Houston D. Luttrell

Committee Members

John J. McDow, Lewis H. Dickson

Abstract

Sowing seed in the soil has been practiced ever since man learned to raise plants for his food. The simplest practice he adopted for raising crops on fields was just to throw seeds or broadcast them on the land where the plants were intended to be grown. With this simple start of the art of sowing, as man learned more and more about the behavior, growth and the art of crop husbandry, he searched for better ways of seeding or sowing seeds in order to accomplish better yields. The growth of plant science and the demand for better seeding practices besides the requirements of seed bed preparation, manuring, weed control, etc., lead him to the investigation and use of several devices or applicances or say equipment for planting seeds. At present the plant science demands the planting of seeds in rows at specified width and at desired spaces between seeds in a row. Of course the distance between rows and spacing between seeds varies according to the nature of the crop. The plant science also demands that seeds to be placed either in groups (otherwise called hills) or single seeds. Placing of seeds in specified rows and at a given spacing is alone not sufficient. They have to be placed at desired depth and an environment of soil is to be created to obtain the desired stand of plants both in number and also in uniformity Seeds not only vary in shape and size with different crops but they also vary in size and shape within the same crop with different varieties and with the same variety crop in seeds. These variations in seeds and variations in the planting practices have lead to the development of various types of planting equipment that are now found in the market. The requirements of planting devices for most of the crops have been fairly accomplished as could be seen from the review of previous work briefly mentioned under Review of Literature. Coming to the requirements of snap beans, they are required to be planted as single seeds in rows as close as cultural operations permit and at uniform spacings within a row in order to have a uniform stand of crop foi' obtaining maximum yields. The usual width between rows is three to five feet for pole beans and 28 to 38 inches for bush beans. The seed spacing within the row varies from 1-1/2 to 4 inches (17). Tests conducted in Pulaski County, Kentucky, with the same fertilizer level and with varied overall spacing of five, seven, and nine plants per foot showed that plants at seven per foot gave the maximum yield (18). Thus, the accuracy with which snap beans are to be planted for obtaining maximum yield is within a very small range. This demands the use of precision planting equipment which could meter beans in singles and plant them at correct spaces in the rows to get the desired stand of plants. The standard horizontal corn planter found in the market with certain modifications of equipment and use of specially designed plates is being used by some farmers for planting snap beans. As these cylindrical shaped snap beans of the same variety vary both in diameter and in length of seeds, they are required many times to be graded to obtain accurate metering. Often ungraded seeds cost less than graded seeds, it is desirable to have a planter which could meter and plant seeds with precision irrespective of the size and shape of the seeds. The requirement of metering seeds of various sizes and shapes needs an approach quite different from the conventional plate metering devices. In the present investigations the possibility of separating single seeds from a group of seeds in a hopper through the use of pneumatic vacuum pressure was explored. It was thought that it would be possible to catch a single seed and separate it from the group by holding the seed with pneumatic vacuum pressure at the end of a suitably designed nozzle, positioned on the periphery of a rotating vertical disc or plate.

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