Concept for Monitoring the Growth and Development of Cotton Plants Using Main-Stem Node Counts

Abstract

Management efficiency in cotton (Gossypium hirsutum L.) can be improved by implementing strategles that may be adjusted in response to expected or realized changes in plant growth and development. We propose that successive counts of main‐stem nodes bearing sympodia with a preflower fruiting structure in the first position are practical, dynamic measurements of plant development. A technique of monitoring number of main‐stem nodes above the sympodial branch bearing a white flower in the first position from the main axis (NAWF) was investigated. The physiological basis of NAWF was established by relating NAWF to other measurements of crop growth and yield. A critical value of NAWF was determined by retention, size, and number of seed associated with first‐position bolls. In separate tests, influences of cultivars, plant densities, irrigation, and two insect pests on NAWF were evaluated. The number of NAWF was closely related to variation in canopy photosynthesis indicating that growth activity of the crop can be monitored by NAWF. Based on individual boll measurements, potential economic value of flowers declined rapidly as NAWF approached 5.0. From regression equations of NAWF by days from planting, the number of days to NAWF of 5.0 (representing the last effective flower population) were calculated and used to distinguish effects of the management factors on plant development. Increased precision and confidence in end‐of‐season management decisions will likely be the first major benefit of this monitoring technique. As effects of additional management factors on NAWF are established, manipulation of the effective fruiting period and developmental pace of the crop should be possible by various combinations of factors, thereby providing a useful management tool.

Yield, Petiole Nitrate, and Node Development Responses of Cotton to Early Season Nitrogen Fertilization

“…Nodal development of cotton was evaluated using nodes above squaring node and nodes about white flower as estimates of crop [16] Similar to petiole NO À 3 -N analyses, node development was only occasionally significantly affected by N treatments in 1995 (data not shown). More significant differences were observed from 1996 to 1998 (Tables 7-10).…”

“…Data collected from these studies included lint yield, plant height, and soil NO À 3 -N. Additionally, nodal development [16] and petiole NO À 3 -N concentration [17] were evaluated weekly through the growing season. Data were analyzed using the Statistical Analysis System (SAS Institute, Inc., Cary, NC, 1999).…”

Factors affecting farmer adoption of remotely sensed imagery for precision management in cotton production

“…Farmers (or consultants) often use the stage of cotton plant growth and development to time the application of inputs such as irrigation water, plant growth regulators, pesticides and harvest aids (i.e. defoliants and or desiccants to prepare the crop for harvest) (Bourland et al 1992). Thus, RS may have great potential in cotton production because imagery can be obtained at regular intervals during the growing season and can be related to current crop status.…”

Cotton Boll Abscission and Yield Losses Associated with First-Instar Bollworm (Lepidoptera: Noctuidae) Injury to Nontransgenic and Transgenic Bt Cotton

“…Scientists with the University of Arkansas have developed a procedure based on the vertical position of the uppermost white ßower along the cotton plantÕs main stem to estimate plant maturity consistently (Bourland et al 1992). Additional research has shown that the Þnal boll population contributing to yield is present on plants when the uppermost white ßower occurs within Þve main stem nodes of the plant terminal (Bernhardt et al 1986, Bagwell 1994.…”