Cotton (Gossypium spp.) produced under fully-irrigated conditions in the Desert Southwest is expensive and management intensive, having many factors that affect cotton growth and development throughout the growing season. Therefore, many in-season decisions need to be made in a timely fashion, which can greatly affect final yield. Cotton monitoring assists producers make informed in-season management decisions: Presented here, is a method of taking simple plant measurements and graphing trends of plant growth and development against standard curves to identify if the crop is developing correctly. The standard curves include upper and lower thresholds, so that "normal" growth and development can be easily identified. Trends that cross the thresholds indicate an abnormal situation, which requires a management correction. The standard curves used in this system were developed in the Desert Southwest under environmental conditions similar to the Trans-Pecos region of Texas (Silvertooth, 1994).

Introduction

The cotton plant must maintain a balance between vegetative and reproductive growth for optimum production. Vigorous vegetative growth (vigor) is important since this provides the structure upon which the plant will set fruit (squares, flowers, and bolls). If a plant grows too vigorously there may be problems with harvest operations (especially in stripper-harvested areas). It may also indicate that the plant is out of balance regarding reproductive growth (lost fruit may result in excessive plant height). The ultimate goal is cotton production, so it is important that the plant hold as much fruit as possible. The measures of growth and development used are height-to-node ratio (HNR), which is the measure of crop vigor and fruit retention (FR), a measure of reproductive growth.