April 18, 2018

Select Max Supplemental Label for Bearing Pome and Stone Fruits

The U.S. Environmental Protection Agency (EPA) has approved a new Supplemental Label for use of the graminicide Select Max 0.97 EC (clethodim) for bearing pome and stone fruits. This includes apples, pears and all other pome fruits, and apricots, cherries, nectarine, peaches, plums and related hybrids. The label also includes low-growing berry crops (except cranberry and strawberry), including low-bush blueberry. Previously it was only available for use on non-bearing fruits.

The label allows use of 12 to 16 fluid ounces (0.09-0.12 lbs active ingredient) per acre of Select Max in each application, with a maximum of 64 fluid ounces per acre per year. There is a 14-day pre-harvest interval (PHI) for all the tree fruit. The PHI for small fruit is 45 days. Always include 0.25% v/v non-ionic surfactant in the herbicide solution (1 quart in 100 gallons of spray solution).
Select Max is effective against all annual grasses, and is especially effective against annual bluegrass, which Poast (sethoxydim) tends to miss. Select Max at the highest labeled rate is moderately effective against quackgrass, orchardgrass and other perennial grasses.

Select Max is similar to the other graminicides, in that it kills grasses slowly. Visual symptoms (yellowing of the leaves) appear about one week after application. Normally, about four to five days after application, the tallest part of the grass plants can be pulled off and will have yellow discoloration at the node where it breaks off. Large, well-established grasses, especially perennials, may need a second application of Select Max or other grass herbicide three to four weeks after the first application to kill them completely.

The Select Max Supplemental Label is part of the Select Max Section 3 Federal label. The Supplemental Label expires in May 2019. By then these uses should be included on the Federal label attached to containers. The new Supplemental Label is available from the internet at CDMS

 

Filed Under: Tree Fruit
July 7, 2017

Getting the Upper Hand on Virginia creeper

Picture 1 – Virginia creeper vine

Virginia creeper (Parthenocissus quinquefolia) is a perennial woody vine that climbs on other objects or trails along the ground.  It is a common weed of orchards, vineyards and blueberry plantation. It is best identified by the typical palmate leaf with 5 leaflets that originate from the same point (picture 1).  Virginia creeper will produce many tendrils with adhesive disks at their tips that will allow the vine to climb upward and to attach to any support. It can grow under a wide range of conditions including dry sandy or moist organic soils, sunny or shady sites, and is tolerant to high salinity.  Plants will often establish through seeds dropped by birds who consumed the small blue berries in fall, but also by the spread of crawling stems that will produce new roots in contact with soil (picture 2). Virginia creeper is often confused with Poison-Ivy (Toxicodendron radicans). However, poison-ivy has 3 leaflets instead of 5 for Virginia creeper and lacks the tendrils and adhesive disks.

As a perennial weed, Virginia creeper will be tough to control as it can easily regrow after foliar injury from its extensive underground root system. When established, Virginia creeper will most often not be controlled with a single herbicide application, and multiple applications will be necessary to achieve acceptable control. Only nonselective postemergence herbicide (glyphosate) must be used to suppress or control this weed. In order to increase the efficiency of postemergence applications during the growing season, remove the vine from their support during winter pruning and lay it on the ground or plan a “cut stump” treatment during the growing season. Do NOT “prune out” the vine during the dormant season.

Picture 2 – Virginia creeper rooting stem

Spot treatment.  Glyphosate may be applied in mid- to late summer after vine flowers in early July until the first signs of fall color appear in the foliage. Good growth and maximum leaf area is needed at the time of herbicide application during the summer.  Wet a minimum of 50 percent of the weed foliage with a 1% glyphosate solution (1.25 oz of 4.5lb acid material per gallon of water) for effective control. For best control, don’t apply on stressed/wilted weeds.

Cut stump treatment. Best results are often obtained in late summer and early fall, but before fall color is observed in the foliage. Apply a 1% glyphosate solution to the cambial areas (inner bark area) of the stump of woody plants IMMEDIATELY after cutting. Cut and treat stumps only when the Virginia creeper is actively growing and not under stress.

WARNING. Injury due to root grafting may occur in adjacent plants. Do not treat cut stumps if there is a possibility of root grafting to desirable vegetation. Do NOT allow contact with green bark, trunk wounds, leaves, or root suckers of blueberry bushes.

The mention of trade names and rates is for educational purposes and does not imply endorsement by the author or the New Jersey Agricultural Experiment Station. Always defer to the product label for instructions on properly applying an herbicide.

Filed Under: Blueberry, Cranberry, Fruit, Strawberry, Tree Fruit, Vegetable Crops, Wine Grape Tagged With: , , , ,
July 6, 2017

Liberty 280 SL label for LibertyLink sweet corn

 

EPA has recently approved a new version of Liberty 280 SL label (see picture).

This new label includes increased LibertyLink (LL) corn rates, increased yearly maximum rates, and a sweet corn section for LL varieties.

Liberty 280 SL is a non-selective herbicide that provides control of a broad spectrum of broadleaf and grassy weed species. Liberty can be used as a burndown treatment prior to planting or prior to emergence of corn, sweet corn, or soybean, as a post-emergence herbicide to control emerged weeds in LL varieties of corn, sweet corn and soybean.

Liberty is a group 10 herbicide (glutamine synthetase inhibitor) that has contact activity and control emerged weeds at the time of application. Liberty provides good to excellent control of various annual grass species, including barnyardgrass, crabgrass, foxtail spp., and fall panicum. Excellent control (> 85%) of tough to control broadleaf weeds has also been notes for pigweed, cocklebur, jimsonweed, lambsquarters, marestail, common ragweed, and smartweed.

Applications of Liberty should be made between dawn and 2 hours before sunset to avoid the possibility of reduced weed control. As with all contact herbicides, uniform spray coverage is necessary to achieve consistent weed control (use at least 15 gal/A in normal situations, 20 gal/A if dense vegetation is present). For best results, apply when weeds are 2-4 inches tall. Apply ONLY over the top of LibertyLink corn, sweet corn, and soybean varieties.

The mention of trade names and rates is for educational purposes and does not imply endorsement by the author or the New Jersey Agricultural Experiment Station. Always defer to the product label for instructions on properly applying an herbicide.

Filed Under: Field, Forage & Livestock, Vegetable Crops
May 5, 2017

Controlling a Noxious Weed of Blueberry Plantations

With favorable weather conditions for germination and growth during the last few days, some of the summer weeds have started to emerge, including one of the most troublesome weeds in our blueberry plantations! Field bindweed (Convolvulus arvensis) is an aggressive rhizomatous perennial vine that belongs to the morningglory family. It spreads by seeds and by a deep, extensive root system. Reports indicate that seeds can persist in soil for up to 60 years, and that roots can grow up to 30 feet deep.

Field bindweed identification

Field bindweed trails prostrate along the ground until it comes in contact with other plants or structures. Stems will then rotate in a circular patter until it makes contact with a solid structure (overhead irrigation pipes, trees, blueberry bushes, other weed species, etc.), then it will wrap around the structure as it grows.

Seedlings (picture 1) emerged in spring.  Cotyledons are square to kidney-shaped. Young leaves are alternate, bell-shaped with nearly parallel leaf margins and generally rounded tips. Leaf bases are lobed. No cotyledons are present when young plants emerge directly from the rhizome. When juvenile stems are broken, they exude a milky sap. On mature plants, leaves are arranged opposite along the stem and are arrow shaped. Lobes at the base of the leaf point away from the petiole. Stems are smooth to slightly hairy.

Flowers (picture 2) are present from June to September and are trumpet shaped, pink to white in color. Field bindweed has two leaf bracts that grow from ½ to 1 inch below the flower, and is a key identification characteristic.  Flowering is indeterminate, so flowers will continue to develop along growing stems until first frost

Field bindweed control

Mowing will not help to control field bindweed because the plant is growing prostrate on the ground (Picture 3). Cultivation may help to reduce bindweed growth and control it over the time but has to be repeated at frequent intervals. Once cultivated, it will usually take 2 weeks to the plant to regenerate fully functional above-ground vegetation, meaning that cultivation has to be repeated every 7 to 10 days.  Consistency in cultivating bindweed-infested soils will promote the progressive depletion of carbohydrates stored in the root system by not allowing the plant to move back carbohydrates produced in the leaves to the roots. It is critical that NO timing be missed or be late! One single missed tillage can negate all the effort expended up to that point. Expect to continue the effort for 4 to 6 months! Success may require more time if the effort was not started when carbohydrate reserves in the weed were low at the start of the process.

Herbicides can be used to control field bindweed in nursery or mature plantations as long as NO herbicide is allowed to contact crop green bark, wounded trunk, leaves, or suckers. Applications of glyphosate containing herbicides (like Roundup) are effective as long as the herbicide is applied on plants that are actively growing and have flowers in late spring/early summer and late summer/early fall. Spring or fall applications may be more effective than applications made during mid-summer. Spot‑apply the higher percentage solution on the label of the product you use and thoroughly wet the foliage up to the drip point.

Repeated applications will be necessary, as the root system on this plant can be so immense that insufficient herbicide is absorbed with a single application.  Use repeated applications, but allow the plant to grow and produce flowers before each subsequent application.  More translocated herbicide will be moved to the root system when the plant is flowering than when vegetatively growing.

Filed Under: Blueberry, Fruit, Tree Fruit
April 22, 2017

Controlling Emerged Marestail in Blueberry

In spring, one of the first weeds that will break through the residual herbicide coverage provided by preemergence applications is horseweed, aka marestail. Horseweed has two primary periods of emergence, from late March through June and from late summer through late fall. Some of the most problematic horseweed emerges in the fall and over winters as small rosettes. If growers don’t control it with fall-applied residual herbicides, the weed has an excellent head start on the spring growing season, especially after a mild winter. Horseweed plants remain in the rosette stage through mid-April, followed by stem elongation (bolting) and rapid growth to an height of 3 to 6 feet. Plants that emerge the previous fall will bolt earlier than spring-emerging plants. Horseweed is most easily controlled when in the seedling, or rosette stage, and spring postemergence herbicides should be applied before stem elongation.

 

Treating them early is the key to success. Control of horseweed when its 2 to 4 inches is more likely than when it’s over 10 inches tall. Remember, most of the horseweed in New Jersey is resistant to glyphosate and there is a good probability that our populations are also resistant to ALS herbicides such as halosulfuron (active ingredient in Sandea) or rimsulfuron (active ingredient in Matrix). So, the most consistent options to control emerged horseweed include paraquat, clopyralid or glufosinate applied to small plants.

Paraquat – Use 2.4 to 4.0 pints/A of Gramoxone SL 2.0. Gramoxone is a contact killer that has no translocation or residual activity. So, best results will be achieved when seedlings are less than 1 inch in diameter. Two applications, two weeks apart are more effective than a single application. Regrowth may occur from the root systems of established weeds. Always use a nonionic surfactant (0.25% v/v) to improve the weed leaf surface in contact with the herbicide and enhance weed control. Do not allow spray or drift to contact green bark, leaves, or fruit as crop damage may result as shown on the picture.  As Gramoxone targets the plant photosystem apparatus, applications made at sunset will increase weed control efficiency by allowing more herbicide to penetrate before being activated by sunlight in the morning.

DANGER: Do not breathe spray mist. Read safety precautions on the label.

 

Clopyralid – Use Stinger at 3 to 4 fl oz/A of. Stinger has a 24(c) Special Local Need label for weed control in blueberry since 2013. Stinger acts as both a postemergence foliar absorbed herbicide and a residual herbicide.  The initial twisting and curling observed after  application to susceptible species is due to the foliar absorption.  Do not apply Stinger from one week prior to bloom until one week after bloom. Stinger can eventually be tank-mixed with Gramoxone to increase the spectrum of weeds controlled and defoliate existing foliage of perennial asters, goldenrod species and mugwort.  Donot allow spray or drift to contact green bark, leaves, or fruit as crop damage may result as shown on the picture. Time all applications to maintain a 30-day PHI (PreHarvest Interval). Do NOT apply Stinger in a hand-held sprayer used to “spray until wet”.  Stinger is a residual herbicide that must be applied on a rate per acre basis with a precisely calibrated sprayer. Read safety precautions on the label.

Glufosinate – Use Rely 280 at 48 to 56 fl oz/A. Rely is a foliar active, nonselective herbicide that controls a broad spectrum of emerged annual and perennial weeds. Best results are obtained when it is applied to actively growing weeds. Glufosinate does not provide residual weed control but can be tank mixed with residual herbicides for broad spectrum control. Contact of Rely with parts other than mature callused brown bark will result in extremely severe damages to the blueberry bush. Do not apply within 14 days of harvest. Warm temperature, high humidity, and bright sunlight will improve the performance of Rely. Read safety precautions on the label.

Filed Under: Blueberry, Fruit Tagged With:
April 20, 2017

Update on Use of Chateau for Weed Control in Potato

Chateau herbicide has a supplemental label for application to potatoes after hilling for preemergence suppression of various broadleaf weed species. This supplemental label will expire on June 30, 2017 and Chateau must not be used on potato after this date.

This supplemental label will not be renewed by Valent as the company is in the process of putting this supplemental label on the federal label. However, this use for potatoes will show up on the revised federal label when it reissues from the EPA.

We currently do not have a time frame for that but it probably will not before June 30. We are expecting that the revised federal label will be issued prior to the use season next year.

Filed Under: Vegetable Crops Tagged With: , ,