Seedling diseases, also known as damping-off (seedling death), are caused by several common soil-inhabiting fungi acting alone or collectively during pre-emergence
and postemergence of cotton seedlings. Seedling diseases are common but often a
minor problem in cotton production areas of Arizona in most years. However, significant stand loss to seedling
diseases can occur sporadically in some fields without
good crop rotation history.
Alternaria leaf spot of cotton is also known as Alternaria leaf blight. The disease was first identified in cotton in the US in 1918 and is now distributed worldwide. Alternaria leaf spot has been considered a minor disease in the cotton growing areas of Arizona.
Goss’s bacterial wilt and leaf blight
(Goss’s wilt) was first recorded in Nebraska in the late 1960s
and is now distributed widely in most states throughout
the Corn Belt. The disease was first detected on field corn
in southeastern Arizona in 2018.
Spray Legally: Summary of Enlist™, Engenia® and Xtendimax® Application Use Requirements on Cotton
Enlist™ One and Enlist Duo are water-based formulations of 2,4-D that can only be sprayed on cotton varieties with Enlist traits. XtendiMax® with VaporGrip® Technology and Engenia® Herbicide are water-based formulations of dicamba that can only be sprayed on cotton varieties with XtendFlex traits. The EPA labels for these 2,4-D and dicamba products include many requirements designed to reduce off-target movement and help limit damage to downwind crops and other susceptible plants. These are summarized in this table comparing 2,4-D and dicamba herbicide products. Check labels and websites for current requirements before spraying.
Cotton stem blight and boll rot is caused by the necrotrophic fungus Sclerotinia sclerotiorum. This pathogen can attack hundreds of plant species including many important agricultural crops such as vegetables, legumes, sunflowers, canola, many flowering bedding plants, and stone fruits.
Variety selection is one of the most important decisions a grower will make contributing to the success of a cotton crop. It is critical, that a grower have as much information as possible in order to make an informed decision regarding variety selection.
Insect Management on Desert Produce Crops: Western Flower Thrips 2016
Western flower thrips are major pests to lettuces, cabbage, and spinach because of the damage they cause to these plants. This article describes their development, Economic Damage, and suggestions for their management.
Insect Management on Desert Vegetables and Melons: Whiteflies 2015
This article describes the sweetpotato whitefly (SWF) in great depth and their relation to Desert Vegetables and Melons. It includes it's history of development and damages it has caused. The article also describes the management of SWF, including sampling/monitoring, natural/biological control, cultural practices, and insecticidal control.
Three maturity groupings are often used to classify cotton varieties, consisting of: 1) short season or more determinate plants, 2) medium season varieties, and 3) long or full season varieties which are more indeterminate in nature. Classification of cotton varieties into one of these three categories is not necessarily straightforward in all cases. In fact, it easily can become a process of “splitting hairs” when making maturity grouping designations for cotton varieties. Nevertheless, maturity designations are commonly assigned to most commercially available varieties, which can effect selection and management.
Soil Management and Soil Testing for Irrigated Cotton Production
Whenever studying cotton, it is a natural tendency to focus on the above ground portions of the plant. However, an equally important part of the plant is the root system, The soil is a focal point of any farming operation.
The approaches and techniques used to produce a cotton crop in Arizona can vary to some degree from county to county, or from farm to farm. However, one of the objectives that has become increasingly common across Arizona is that of achieving earliness with a crop.
Estimating the Vegetative/Reproductive Balance in Cotton Growth
A healthy, well-developed cotton plant that is capable of high yield requires a strong root system, mainstem structure, sufficient leaves, and numerous fruiting branches to support a good boll load. Too small a vegetative structure on the plant results in reduced yield potential, and too much vegetative development, which is usually done at the expense of fruit set and yield.
Soil Fertility and Soil Testing Guideline for Arizona Cotton
According to all available evidence, there are 20 total nutrients necessary for complete plant growth and development. Not all are required for all plants, but all have been found to be essential to some.
There are several factors which are important to consider in managing defoliation. Factors such as plant-water relations, Nitrogen (N) fertility status, the extent of honeydew deposits on the leaves from insects such as the sweet potato whitefly or aphids, and weather conditions following the defoliant application are all important in terms of the final defoliation results.
This bulletin deals with the physiology of cotton defoliation and attempts to describe what conditions must exist inside the plant in order for defoliation to occur. It is important to understand the basic physiological processes involved in order for best crop management practices to accomplish a successful defoliation.
After stand establishment, the next critical stage in the development of a cotton crop is the initiation of the first squares, or floral buds, which could develop into the plants’ first boll. This is an important step for a cotton crop and one which is usually followed closely by the attentive farmer.