Category Archives: Diseases
Corn Diseases in South and Central Texas, So Far
This season has been unusual for corn diseases. Early in the year, starting in south Texas and progressing north, the fungal disease, northern corn leaf blight (Figure 1), has been very prevalent. Usually, a few lesions of the disease are seen on the lowest leaves and the disease never progresses. Disease development is driven by frequent rain and temperatures lower than 80°F. In a typical Texas growing season, infrequent rain, but moreover increasing temperatures will hinder the fungus. Weather conditions early in the season supported disease development. There… Read More →
Unique COVID-19 Social-Distancing Message for Texas Farmers
AgriLife agronomist alerting Texas farmers about their importance to remain healthy Adapted from AgriLife Today, April 4, 2020 The Texas A&M AgriLife Extension Service has specialists and agents statewide helping to keep Texans educated, informed and safe amid the COVID-19 pandemic. Calvin Trostle, Ph.D., AgriLife Extension agronomist in Lubbock, is a regular guest on many agriculture radio programs in the Texas High Plains and beyond. His message, however, is reaching farther than ever before as stations share his message over two dozen syndicated affiliates. Given his… Read More →
Hemp Disease Prognosis for Texas
Dr. Tom Isakeit, Professor and Extension Plant Pathologist There is intense interest in growing hemp (Cannabis sativus) commercially in Texas. Along with considerations of applying the best agronomic approaches for growing it, there is a need to consider potential pitfalls, particularly insect pests and diseases. There is very little information on hemp diseases in Texas. The national host indices list just three fungal diseases of hemp in Texas, but this probably reflects a lack of observations. With a small hemp acreage in Texas, there will probably be a… Read More →
Causes of Blank Heads or Unfilled Kernels in Grain Sorghum
Dr. Calvin Trostle, Extension Agronomy, TAMU Soil & Crop Sciences, Lubbock, (806) 723-8432, ctrostle@ag.tamu.edu This past week I received digital pictures and sorghum head samples from two different fields where grain sorghum fill was incomplete. This highlights the most difficult field situation I encounter in grain sorghum for 20+ years. What is the cause? What is particularly frustrating is production conditions often appear to be good. Often it is difficult to pinpoint any reasonable cause. Weather often is not a known factor, e.g. there were no extremes… Read More →
Cotton Blue Disease, A Virus Disease Not in Texas, So Far
A new virus disease of cotton found so far in several southeastern US states has attracted a lot of attention lately. This is the “cotton blue disease”, which is caused by the cotton leaf roll dwarf virus. Symptoms are seen in the new growth following virus infection and include stunting, blistering or crinkling of leaves (Figure 1), and downward cupping of leaves (Figure 2). Other symptoms can include reddening, shortened internodes, upward cupping of leaves and abnormal top growth. Plants may also exhibit a green-blue leaf… Read More →
Mid-Season Assessment of Rhizobium Nodulation in Texas Peanuts and Other Legumes
Dr. Calvin Trostle, Extension Agronomy, TAMU Dept. of Soil & Crop Sciences, Lubbock, (806) 746-6101, ctrostle@ag.tamu.edu; Dr. Emi Kimura, Extension Agronomy/State Extension Peanut Specialist, TAMU Dept. of Soil & Crop Sciences, Vernon, (940) 552-9941, emi.kimura@ag.tamu.edu June 6, 2019 Note: The following comments address field observations primarily for the Texas High Plains peanut production region but are applicable to other Texas regions as well. We discuss other legume crops in the document as well. Legumes are a valuable asset in any Texas crop rotation. They offer a… Read More →
Mid- to Late-Season Weed Control Options for Peanut
Weed pressure seems higher this season due to better than average soil moisture. Herbicides applied preplant and at planting have been effective, but new weed flushes following rainfall or irrigation are likely as soil applied herbicides are dissipating. Herbicides applied at early-postemergence that do not have soil activity are also prone to allow new weed flushes. In other words, good early season weed control may need some attention because previously applied herbicides have dissipated over time. So what options do we have from now to early peg stage?… Read More →
Identification of Early-Season Stand Loss and Seedling Diseases of Cotton
Early-season stand loss of cotton could be the result of fungal pathogens or, in the case of some fields in the Upper Coast counties (e.g. Wharton and Fort Bend), high populations of reniform nematodes. Seedling death from fungi can vary from season to season and severe impacts are usually associated with cool, wet conditions at planting or shortly after emergence. Although the damage from stand loss can’t be undone during the current season, losses in future crops are somewhat preventable. In contrast, stand loss from… Read More →