GENERAL CONDITIONS:
Cotton in general is doing good giving the weather conditions over the last 7 to 10 days. Cotton in the area is ranging from just emerging up to pinhead squares. We have not found any insect pest in our cotton fields, but are starting to see a few more beneficials move into fields. These are mostly hooded beetles and crab spiders. Fertilizer applications, weed management, and managing growth using Plant Growth Regulators (PGRs) is what we need to be focused on for the next week to two weeks, especially if the rain chances materialize over the weekend.
Peanuts are growing good, but with this hot weather water consumption has increased. All fields in the scouting program started blooming this week, and has increased the water demand for the crop. Diseases have not been found yet, but there are still white grubs and wireworms being found in fields. Nitrogen applications in fields low on root nodules and preparing sprayer and/or chemigation systems are what should be focused on in the coming days.
A much need cool down is forecasted for this weekend and into early next week, as a cool front move through the area. Temperatures are expected to be in the 70s for daytime highs and in the 60s for nighttime to early morning lows. We are also getting a much-needed chance of rain starting this afternoon, as I am finishing this newsletter, parts of Gaines and Yoakum Counties are receiving showers. This rain will help our dryland crop progress, as it is limping along waiting for much needed moisture, and will help prevent drought stress in our irrigated crop which could cause square loss in cotton and poor pollination and pegging in peanuts, let’s just hope these storms are not accompanied by hail, and high winds.
COTTON:
Cotton is ranging from 2-true leaves up to 8 -true leaves, and pinhead squares are starting to form. This week squares were found in half of the scouting programs fields, and the first fruiting branch is between node 5 and node 7, with a 100 percent square retention. This variability in growth stage puts us in a situation where we are still checking for thrips in some fields, while in others we are moving to check for fleahopper and other plant bugs. Over the course of the last seven days, no fleahoppers have been found, but I would like to talk about identification and economic thresholds for fleahoppers in this newsletter to give you an idea of what we need to be looking for. Cotton fleahopper are pale green in color and are about 1/8th of an inch long. Their body is flat and elongated with an oval outline. On the back of the adults there are minute black hairs and spots. Nymphs of the cotton fleahopper appear the same as the adults, but without wings, however, initially are white in color until they feed. Once a Nymph has fed their color will turn to pale green with reddish eyes. Cotton fleahoppers have numerous wild host which they can overwinter on, these include silver leaf nightshade, woolly croton, and horsemint to name a few. Cotton fleahoppers use their piercing sucking mouthparts to remove plant sap from the tender portions of the plant. Square that are smaller than pinhead size is most susceptible to fleahopper damage, and square feeding can cause the square to die, and turn brown. Economic thresholds for fleahopper in our area is based on the number of insects per 100 terminals, and the percent of square set (Table 1). Treatment for fleahoppers is rarely justified after the 3rd week of squaring, because at that time we should be blooming and at this point cotton is typically able to compensate for some square loss. Last year Kerry Siders, Extension Agent-IPM for Hockley Cochran and Lamb Counties and Dr. Pat Porter, Extension Entomologist in Lubbock produced an excellent YouTube video covering the fundamental of scouting for fleahoppers on the Texas High Plains, it can be found at https://www.youtube.com/watch?v=epVctkRkTHs. Additional information of biology and chemicals that effectively manage fleahopper populations can be found at http://cottonbugs.tamu.edu/fruit-feeding-pests/cotton-fleahopper/.
.
PEANUTS:
Peanuts are faring well for the recent hot and dry spell we have been in, and all the peanut fields began blooming this week, with one field starting to show peg development. This is time where we need to be applying our nitrogen to fields that are lacking in root nodules. Over the last two week the field scouts and I have been taking nodule counts, and most of the fields are averaging less than 10 nodules per plant. This low nodulation could be because of the roller coaster of a weather pattern we have been on the last 6-8 weeks, lack of putting inoculant down, or even inadequate storage of inoculants. With most of the fields having below 10 nodules per plant, these fields will benefit from a nitrogen application, and fields that have less than 6 nodules will need Nitrogen applications.
Diseases have yet to be found in the scouting program’s fields, and we are getting to the time where a shot of a fungicide such as Azoxystrobin (Abound) can be used as a preventative. Timing of this application typically occurs between 60 and 90 days after planting. When getting ready to apply we want to make sure we are starting to set pegs, as this will allow you to maximize the amount of fungicide in the active pod development zone of the soil. Knowing what pod rot pathogens are present in your field can help you to effectively manage this disease by selecting the correct fungicide, as not all fungicide effectively manages both pod rot pathogens. Azoxystrobin the active ingredient of Abound, Artisan, and Convoy for example is active against Rhizoctonia, but is only known to suppress Pythium pod rot, at the maximum labeled rate of 24.5 oz/acre. Pythium pod rot on the other hand can be effectively managed by using Ridomil, which has numerous formulations such as liquid and granular. The last thing to consider is application method. These products work extremely well when applied using a chemigation system, but can lead to bare soil being treated. Application cost can be reduced when these products are banded over the effect pegging and pod development zone, but it is best to increase the carrier volume to a minimum of 20 gallons as some fungicides are such as Ridomil formulations bind to the surface of leaves rather quickly. Irrigating shortly after application can also increase the amount of fungicide that reaches the pod development zone.
Thank you to all the sponsors of the South-West Plains IPM Program. The sponsors of the program for the 2017 growing season are below.
Platinum Sponsors:
Gold Sponsors:
Doyle Fincher Farm
Golden Peanuts and Tree Nuts
Silver Sponsors:
Birdsong Peanuts
Bronze Sponsors:
Crop Production Services
New-Tex Gin, Inc.
No comments:
Post a Comment