RESEARCH & PROMOTION -
A Multi-Purpose Crop Management Tool
While COTMAN’s initial focus was on terminating insect crop protection applications based on nodes-above-white-flower (NAWF), using NAWF information soon led to using COTMAN for determining optimum defoliation timing as well.
Soon researchers started understanding the significance and impact of pre-first flower nodal development and retention of squares prior to flowering.
“It was then recognized that COTMAN needed to be separated into two parts, BOLLMAN and SQUAREMAN,” says Fred Bourland, cotton breeder, University of Arkansas (U of A) Northeast Research & Extension Center.
In relation to the target development curve, SQUAREMAN may be used to monitor the crop’s development up to the appearance of first flowers, while BOLLMAN is used during the effective flowering phase to monitor crop stress. By identifying and monitoring the maturity of the last effective boll population, BOLLMAN helps users make informed crop termination decisions.
With the evolution of COTMAN, researchers, with long-term funding from Cotton Incorporated, have conducted regional studies to expand its use to terminate irrigation.
“With the cost of every input escalating, knowing the best time to terminate irrigation is becoming more important than ever,” says Earl Vories, agricultural engineer, USDA-ARS Cropping Systems & Water Quality Research Unit.
“Irrigation termination must be based on the cost of irrigation, the price of cotton and obtaining the maximum economic yield. With the cost of diesel going through the roof, recognizing the best time to shut down irrigation could literally save more than $25 an acre in many cases.”
From 2000 to 2007, studies were conducted in Arkansas, Louisiana, Mississippi and Missouri. Additional studies were conducted in Texas but were analyzed separately from the Mid-South locations. At each location, weekly NAWF data was collected, from early flower until NAWF.
“We sequentially terminated irrigation in different sections of the field allowing us to see the effect of later irrigation,” says Vories.
Interpretations of initial findings showed the last irrigation treatment that “paid for itself” came earlier in the north (where the growing season is shorter) than it did at the sites that were located farther south (where the growing season is longer).
“We are still crunching all the numbers, and that information will help us be more precise in our recommendations,” concludes Vories.
Since the beginning of COTMAN’s development, the U of A has played a vital research and development role in almost every aspect of the process from distribution of software updates to spearheading research leading to new uses.
Personnel changes at the U of A have afforded an opportunity for the Texas AgriLife Research & Extension Center to serve COTMAN users moving forward.
“We will strive to maintain the same high level of assistance and enthusiasm when users have questions about COTMAN,” explains Dr. Dan Fromme, assistant professor & Extension agronomist, Texas AgriLife Extension Service, Texas A&M University.
The COTMAN manual and 2008 COTMAN III software may be obtained by contacting your Cooperative Extension personnel. Support for COTMAN is available by calling (361)-265-9203. Users may also visit http://cotman.tamu.edu to report problems or submit questions.
The Cotton Board, which
administers the Cotton Research and Promotion Program conducted by Cotton
Incorporated, provided information for this article.