Excess moisture on the crop before harvest can have detrimental effects on the

modern harvest process in terms of picking efficiency and the ability to store seedcotton

safely and without degrading fibre quality. Modern ginning is also highly

automated and productive, and an excess or deficiency of moisture has significant

effects on processing efficiency, fibre quality and gin turn-out.

Ginning in Australia starts with seed-cotton delivered as a module to the gin. The

module is opened by a series of beaters and the seed-cotton transported by air

through ducts to one or a series of pre-cleaners that remove large trash, e.g. sticks,

stones, unopened bolls, before the gin. If the seed-cotton is too wet pre-cleaning

may be preceded by passage through a drying tower or chamber where the seedcotton

is dried with large volumes of dry heated air. Drying wet cotton improves the

cleaning ability of the seed-cotton and improves classing grade. At the gin lint is

separated from the seed after which it travels by air through one or two lint cleaners

for further cleaning and preparation. Moisture can be added to dry cotton prior to the

gin stand at either the pre-cleaning stage, although addition at this point is not usual

in Australia, or after the conveyor distributor above the gin stand, which although

more typical in modern gins is not standard in Australia. Lint from the gin stands is

consolidated at the battery condenser at which moisture is typically added via sprays

or humidified air to ease the high pressure required to press each bale and to

improve gin turn-out and bale weight.

This report reviews current literature and Australian industry behaviour with regards

to the management of moisture in cotton from harvesting through to the bale storage

in warehouses. Its aim is to provide ginners with an up-to-date and concise

collection of information on the subject of measuring and managing moisture in

cotton during early stage processing and shipment.

Publications reviewed for this report include:

- A number of popular monographs on fibre and cotton fibre properties;

- Beltwide Cotton Conference Proceedings;

- United States Department of Agriculture (USDA) Agricultural Research Service

(ARS) publications and project descriptions including the most recent Cotton

Ginners Handbook (December 1994);

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- Papers from peer reviewed journals including the Journal of Cotton Science,

Textile Research Journal, Transactions of the American Society of Agricultural

Engineers (ASAE), now American Society of Agricultural and Biological

Engineers (ASABE), and the Journal of the Textile Institute;

- US patents describing recently introduced moisture sensors and moisture

management systems;

- Trade journal articles and opinion pieces from The Australian Cotton Grower,

Delta Farm Press and The Cotton Gin and Oil Mill Press;

- Marketing and technical information published by businesses that supply plant

and technology for moisture measurement and replenishment in gins.

Information on Australian industry behaviour and attitudes toward moisture

measurement and restoration was gathered as part of; the Best Management

Practice (BMP) Gin Audits of 28 of the 34 gins operable in Australia, conducted

earlier in 2007; the Australian Cotton Industry Ginning Survey conducted on 17 of the

34 gins operated in 2006; plus collected notes from discussions with growers, pickers

and ginners over the last five years.

The first section describes current knowledge of the physical and chemical

relationships between cotton and water and the generic methods and standards used

to measure cotton fibre (lint), seed-cotton and fuzzy seed moisture. The next three

sections describe the effects of moisture on fibre quality at harvesting and module

building; during cleaning and ginning; and in the bale at pressing and warehousing.

The last section describes the range of commercial sensors and systems currently

available to measure and control moisture in cotton.