((_, , iv'~t I r, ._, < '1.,A r:f r'9 N .N N4 \ L Li { I a ,, JR t.i 7. / jd CONTENTS INTRODUCTION .. ......................................... Classification, Description, and Distribution ........... Germination and Seed Longevity ..................... ............................... Chemical Control MATERIALS AND METHODS .......... 7. ...................... Page 3 6 6 7 7 7 8 Germination Tests.................................. Moisture Stress .................................. Temperature .................................. .................................. Scarification Oxygen ........................................ Growth and Development........................... Planting Depth .................................. Soil pH ......................................... .................... ........... Soil P and K Biology ............................. Competition with Soybeans ....................... Herbicide Evaluation..............................10 Soil-applied Herbicides ............................ Foliar Applications: Herbicides, Rates, and Times of Application ............................ Foliar Applications: Acifluorfen and Bentazon Rates and Frequency...........................11 Balloonvine Control Systems ..................... RESULTS AND DISCUSSION ................................. 8 8 8 8 9 9 9 9 10 10 11 12 12 Germination Tests ................................. ............... Scarification ....................... ........................ ............ Oxygen Moisture Stress ................................. Temperature ................................. Growth and Development..........................15 Planting Depth ................................. ..................... Soil pH .................. . ...................... Soil P and K ............. Biology ........................................ Competition with Soybeans ........................ Herbicide Evaluation ............................. Soil-applied Herbicides ........................... Foliar Applications: Herbicides, Rates, and Times of Application ........................... Foliar Applications: Acifluorfen and Bentazon Rates and Frequency ........................... Balloonvine Control Systems ...................... SUMMARY .................................................. LITERATURE CITED .............. ........................... 12 12 13 13 14 15 16 16 17 19 19 19 20 20 20 27 APPENDIX ....................................................... FIRST PRINTING 3M, MARCH 1983 28 29 Information contained herein is available to all persons without regard to race, color, sex, or national origin. BALLOONVINE BIOLOGY AND CONTROL IN SOYBEANS EDDIE R. JOLLEY, R. HAROLD WALKER, JOHN A. McGUIRE, S. K. JOHNSTON, D. S. MURRAY, and J. C. WILLIAMS1 INTRODUCTION BALLOONVINE (Cardiospermum halicacabum L.) is a problem weed for soybean [Glycine max (L.) Merr] producers, particularly those producing certified seed. The Alabama Crop Improvement Association has annually rejected, over the past 5 years, an average of 1,100 acres of soybeans from certified seed production because of balloonvine infestations. 2 Mechanical separation of balloonvine seed from soybean seed is difficult because of their similar sizes, shapes, textures, and densities (4). Therefore, standard seed cleaning facilities fail to adequately remove the balloonvine seed, yielding seed beans contaminated with balloonvine seed. This is unacceptable since it perpetuates the weed problem. One type of seed processing equipment has been effective in separating the two seeds. It utilizes an electric, lightsensitive eye. Unfortunately, it is slow and the machine with a single-eye unit costs in excess of $5,000. 3 Hand separation is 'Former Research Associate and Associate Professor, Department of Agronomy and Soils; Associate Professor, Department of Research Data Analysis; former Graduate Research Assistant and Assistant Professor (resigned, now at Oklahoma State University), Department of Agronomy and Soils; and Professor, Department of Research Data Analysis, respectively. 2 Personal communication, J. P. Bostick, Alabama Crop Improvement Association, Auburn, Alabama 36830. 3 Personal communication, A. H. Boyd, Mississippi Agriculture and Forestry Experiment Station, Mississippi State University, Mississippi State, Mississippi 39762. ALABAMA AGRICULTURAL EXPERIMENT STATION 4, tt FI(. I I. IIllonlllls lat11'n litea sued noitt similarity in setd sinus and shape. FIG. 2. A Notig balloonvint p1hiit ppros inat t I 20) dlas after emlltrge ntet FIG. :. Balloons nt plat nih oss ing flossters anlld sted piids. ITli plaints art suppoirtted bs siobeans. F IG. 4. AxilIary tendrils enable balloonovine plants toi mb1 onl littler plants. 3 '4 44 .w'4 ~' '.5 4' ~'- AI I, A-, AD 2 ~ tn ®.- / A.1 .M ), s°. J L4bJ* BALLOONVINE-BIOLOGY AND CONTROL A.' . e :. F I( 5. balloonvine flowecrs ar' small. wshi te, and~ abounIt the sire of a pencil eraser. FIG. 6. Ball oonvi ne inft-st inig a field in the Bl ack BelIt. FIG. 7. The balloonvine fruit is a 3chambered capsule; note immature green seeds and inflated capsules. FIG. 8. Mlature balloo011vin e seed pod that h as ruptu red an d exposed the seed. V m 7t i? I ALABAMA AGRICULTURAL EXPERIMENT STATION also effective, but it is a slow and costly process. Because balloonvine cannot be readily removed from soybean seed, it has been designated as a noxious weed in Alabama and other Southern States. Classification, Description, and Distribution Balloonvine is reported to have originated in Mexico or Central America and is considered an ornamental escape. As early as 1820, it was reported to have been abundant in central Oklahoma (2). A member of the soapberry family (Sapindaceae), it grows as a summer annual in the Southern United States, mainly in areas of intensive soybean production (5,6). It has also been found along fence rows, around old home sites, and in areas subject to frequent flooding. In Alabama, infestations of balloonvine have been observed along the Alabama, Cahaba, and Tennessee rivers. Occasional infestations have been found in pastures in north-central counties. No infestations have been found in the Wiregrass area. Balloonvine is a diminutive, shrubby, many-branched plant. Unlike many other vines, axillary tendrils provide support for this climbing plant. Stems are from 3 to 6 feet in length. The trifoliolate leaves are biternately divided into lanceolate segments, coarsely lobed, and weakly pubescent. White flowers, appearing in the early summer, are irregular with four sepals and four petals. There are eight anthers and three filiform stigmas. The inflorescences are arranged as cymes of three to five flowers. The resulting green capsular fruit is inflated, pubescent, and obovoid, containing one seed for each of its three locules (7). The seed of balloonvine are spherical and approximately 3.6 millimeters in diameter. Seed size varies and appears to be dependent upon growing conditions. Balloonvine seed number 4,500 to 5,500 per pound, which makes it similar in size to soybean seed (2,700 to 3,700 per pound). The balloonvine seed testa is black with a white heart-shaped area around the hilum (7). Because of the shape and coloration of the seed, the plant is sometimes referred to as the "8-ball weed" (1), figures 1-8. Germination and Seed Longevity Intact, mature balloonvine seed germinate poorly. This has been attributed to a hard and thick seedcoat. In an earlier work, Heit (4) showed that germination was only 30 percent BALLOONVINE-BIOLOGY AND CONTROL 7 after 4 weeks. Some seed required 4 to 6 years to germinate. For these reasons, once balloonvine is introduced into an area, its survival is virtually assured. Heit also found that consistent and rapid germination of balloonvine seed was obtained by scarification in concentrated sulfuric acid for 30 minutes. Chemical Control Until now, little information has been generated on the growth and development of balloonvine, let alone the control practices needed in soybeans. In 1976, Oliver et al. (unpublished data, University of Arkansas) found that preemergence treatments of metribuzin, early postemergence over-the-top applications of bentazon, and postemergence directed treatments of RH-2915, linuron +2, 4-DB, or metribuzin +2,4-DB all provided excellent (95 percent) balloonvine control in soybeans. Street et al. (8) also found that paraquat or 2,4-DB applied postemergence provided 70 percent balloonvine control. MATERIALS AND METHODS This bulletin summarizes the results of a series of balloonvine biology and control experiments conducted over 4 years (1977-80) at the Alabama Agricultural Experiment Station, Auburn University. Experiments were conducted at the Main Station, the E. V. Smith Research Center, and the Black Belt Substation, located at Auburn, Shorter, and Marion Junction, respectively. The purposes of these experiments were: to identify germination, growth, and reproductive characteristics of balloonvine, determine competitive effects with soybeans, and evaluate methods of control in soybeans. Germination Tests Response of balloonvine to moisture stress, temperature, scarification, and oxygen concentration was determined in several laboratory experiments. Experiments were conducted in dark, thermostatically-controlled incubators, unless indicated otherwise. The seed were placed in 3-inch diameter petri dishes on two sheets of germination matting paper. Seed were recorded as germinated when the radicle had reached a length of 2 millimeters. A completely randomized design was used and all experiments were repeated. ALABAMA AGRICULTURAL EXPERIMENT STATION Moisture stress Aqueous solutions with osmotic potentials of 0, -2, -4, -6, and -8 bars were readied by dissolving appropriate amounts of polyethylene glycol in a quart of distilled water. Balloonvine and soybeans were moistened with 2 teaspoons of the appropriate solutions. Germination counts were made every 2 days for 14 days. Naked balloonvine seed (seed coats removed) were also tested. Germination was evaluated after 3 days. Temperature Thermostatically-controlled incubators were set at 59 ° , 68 °, 77 ° , 86 ° , 95 ° , and 104°F. Petri dishes containing the acidscarified balloonvine seed were placed in incubators at the designated temperatures. Germination was determined daily for 7 days. Scarification Balloonvine seed were scarified in concentrated sulfuric acid for 1, 2, 3, and 4 hours. Germination was evaluated daily for 7 days. Oxygen The effect of oxygen on balloonvine germination was determined using continuous gas flow and acid-scarified balloonvine seed. Either compressed N2 (nitrogen gas), compressed air, or compressed 02 (oxygen gas) was used to establish oxygen levels of 0, 21, and 100 percent, respectively. Seed were placed in 1-inch diameter petri dishes supported by a cylinder above the 1 pint of distilled water in the 1-quart, wide-mouth jar. Each dish contained germination matting paper and a cotton wick extending into the water to maintain seed moisture. Jars were sealed with stoppers having air inlet and outlet holes. Air flow was approximately 5 milliliters per minute, figure 9. A controlled environment chamber with an alternating 86°F day and 68°F night temperature and a 14-hour day was used. Germination was recorded after 3 days. Growth and Development Several experiments were conducted in a greenhouse or growth chamber to determine the response of balloonvine seed to planting depth, soil pH, and soil P and K. Field experiments were conducted to study balloonvine biology and competition with soybeans. All experiments were replicated and repeated. BALLOONVINE-BIOLOGY AND CONTROL Plantingdepth Balloonvine and soybeans were planted at -, 1-, 21/a - , 31/2- , and 43/4-inch depths in a Marvyn loamy sand and a Houston clay soil held by 1-quart cartons. Cartons were subirrigated to minimize soil crusting and compaction. Cartons were placed in a controlled environment chamber with a 14-hour day and alternating temperatures of 86°F days and 68°F nights. Emergence was recorded after 1 day and every 2 days thereafter for 14 days. Soil pH Harselle sandy loam from the Sand Mountain Substation, Crossville, with a pH of 4.9, was used in this study. Selected soil pH levels of 5.9, 6.3, and 6.9 were established by adding Ca(OH)2 to the original soil. Fumigation with methyl bromide, appendix table 1, was used to reduce the nematode population. Scarified balloonvine seed and soybeans were planted 1inch deep in 3.3 pounds of soil held by styrofoam cups. Seedlings were thinned to three per cup after 14 days. Cups received 0.2 gram NH4NO3 biweekly. Plant dry weights were measured after 45 days. Experiments were conducted in air conditioned greenhouses from June through September 1977. In the first test, temperatures averaged 104°F maximum days and 74°F minimum nights. The second test had average temperatures of 99°F days and 68°F nights. Soil P and K Three soil P levels (14, 42, and 73 pounds per acre) were established by adding CaHPO4-2H20 to Marvyn loamy sand obtained from the Agronomy Farm in Auburn, Alabama. Three soil K levels (16, 40, and 140 pounds per acre) were established by adding KC1 to the soil. Scarified balloonvine and soybean seed were planted 1 inch deep in 2.2 pounds of soil held in individual cups. Seedlings were thinned to three per cup after 10 days. Two weeks after planting, all cups received 0.2 gram NH4NO3. After 26 growing days, plant dry weights were obtained. Biology Biology studies were initiated on the Auburn University Agronomy Farm where scarified balloonvine seed were planted at 2-week intervals starting April 11 in 1977 and April 10 in 1978. Plantings continued through September of each 10 ALABAMA AGRICULTURAL EXPERIMENT STATION year. Plots were fertilized at planting according to soil test recommendations. Each plot was 45 square feet with five plants per plot, supported with a wire mesh. Carbofuran and carbaryl were used to control nematodes and foliar feeding insects, respectively. Urea was applied twice as a sidedressing supplying 50 pounds per acre N each time. Irrigation was used as needed. Dates of emergence, plant heights at 5 weeks, dates of flowering, and seed production were recorded for the five plants. Competition With Soybeans The effect of full season balloonvine competition with Ransom soybeans was determined at the Black Belt Substation, Marion Junction, in 1977 and 1979 (1978 abandoned). A splitplot design was used with soybean row spacings as the main plots and weed densities as sub-plots. Soybean seed were planted June 27, 1977, and May 17, 1979, in 24- and 36-inch rows. Plots were five rows x 33 feet in length. Scarified balloonvine seed were planted 4 inches to right of the two center rows. Balloonvine plants were thinned to give densities of 0, 2, 4, 8, 16, 32, and 40 plants per 33 feet of row. Fertilizer.was applied as recommended by soil test results. Alachlor (1.5 pounds per acre) and carbaryl (1.8 pounds per acre) were used to control annual grasses and armyworm (Laphygma frugiperda Smith), respectively. A self-propelled small plot combine was used to harvest the two center rows of each plot. Balloonvine seed were hand separated from the soybean seed and counted, after which the soybean seed were weighed. Herbicide Evaluation Soil-applied Herbicides In 1977 and 1979, responses of balloonvine and Ransom soybeans planted at two depths were determined to preplant incorporated (PPI) and preemergence (PRE) applied herbicides. Paired, 15-inch-wide rows of acid-scarified balloonvine and soybean seed were planted at 3- and 21/3-inch depths in a Marvyn loamy sand. Plots, 25 square feet, were arranged in a split-plot design with four replications. Herbicides were applied with a compressed-air, tractor sprayer and, where appropriate, were incorporated with a tandem-dsc harrow operating at a 4-inch depth. Visual evaluations were made to BALLOONVINE-BIOLOGY AND CONTROL 11 determine activity of the herbicides on balloonvine and soybeans. These and other visual evaluations were based on a scale of 0 to 100 percent, where 0 = no effect and 100 = complete kill. Foliar Applications: Herbicides, Rates, and Times of Application Effects of herbicides applied postemergence, (Post Test I) on balloonvine were determined in 1978 at the E. V. Smith Research Center, Shorter. Herbicides normally applied as postemergence over-the-top (POT) or postemergence directed spray (PDS) treatments were all applied POT in single and double applications. Acid scarified balloonvine seed were planted in a Norfolk loamy sand. Plots were two, 36-inch wide rows, 20 feet long, arranged in a split-plot design containing four replications. Applications were made with a compressed-air, tractormounted sprayer. Timing for postemergence herbicide applications to balloonvine was determined in tests conducted during 1978 (Post Test II) and 1979 (Post Test III) at the E. V. Smith Research Center. Acid-scarified balloonvine seeds were planted in paired 15-inch-wide rows. Plots, 25 square feet, were arranged in a split-plot design with four replications. Applications were made with a compressed-air, tractormounted sprayer or a CO2 backpack sprayer. Treatments were applied to balloonvine plants 3, 7, 18, and 27 inches tall. Foliar Applications: Acifluorfen and Bentazon Rates and Frequency To determine the effectiveness of multiple postemergence applications of herbicides for balloonvine control, two separate tests were initiated in 1978. Acifluorfen and bentazon were evaluated in Post Test IV and Post Test V, respectively. Rates, times, and numbers of applications were variables in these studies, appendix table 2. In 1978, an area of Norfolk loamy sand was overseeded with acid-scarified balloonvine seed. Bragg soybeans were planted on July 18 in this area at the E. V. Smith Research Center. Plots were four, 36-inch-wide rows, 20 feet long, arranged in a randomized complete block design. Applications were made with either a compressed-air, tractor-mounted sprayer or a CO2 backpack sprayer. 12 ALABAMA AGRICULTURAL EXPERIMENT STATION In 1979, the acifluorfen test was repeated (Post Test VI). On May 11, Bragg soybeans were planted in the area overseeded with acid-scarified balloonvine. Treatments were applied as in 1978. Plots were four 36-inch-wide rows, 25 feet in length. The right two rows of each plot were cultivated June 19. The test was repeated in 1980 (Post Test VII). Balloonvine Control Systems From the results of previous herbicide experiments, a herbicide system test (System Test I) was initiated in 1979 to find which combinations provide the best selective balloonvine control in soybeans. Methods, rates of application, and combinations evaluated are given in appendix table 3. At the E. V. Smith Research Center, Bragg soybeans were planted in a Norfolk loamy sand. The area had been overseeded with acid-scarified balloonvine. A randomized complete block design with four replications was used. Plots were four 36-inch-wide rows, 25 feet in length. The right two rows of each plot were cultivated once. Incorporation of herbicides was done immediately after application with a tandem disc-harrow operating at a 4-inch depth. Treatments were applied with either a compressed-air, tractor-mounted sprayer or a CO2 backpack sprayer. Soybeans were harvested November 15 with a self-propelled plot combine. Balloonvine seed were hand separated from the harvested soybeans and counted. The same test (Systems Test II) was repeated in 1980. Soybeans were planted May 27 and harvested November 21. RESULTS AND DISCUSSION Germination Tests Scarification Maximum germination of balloonvine was obtained with 3 hours of acid scarification, while a decline in germination occurred with both the 2- and 4-hour treatments, table 1. Balloonvine is 100 percent hard seed, which 1-hour acid scarification did not measurably affect. Heit (4), however, reported maximum germination of balloonvine seed with 30-minute acid scarification. Variations in seedcoat thickness may be responsible for the difference in the scarification time reported. Seedcoat thickness variations may also have been responsible for the low germination of only 55 percent. En- BALLOONVINE-BIOLOGY AND CONTROL TABLE 1. INFLUENCE OF ACID SCARIFICATION ON BALLOONVINE GERMINATION 13 Acid scarification Germination 1 2 3 4 Hr. ................ ................ ................ ................ Day 1 Day 2 Day 3 ...... ..................... Oa' Oa Oa 13bc 27b 37b 15c 35b 41b 10b 27b 36b Day4 Day5 Day6 Pct.. ..................... Oa Oa Oa 43b 46bc 46bc 46b 52c 54c 40b 42b 44b Day7 .. Ga 46b 55c 46b 1Means within columns followed by the same letter are not significantly different at the .05 probability level by Duncan's Multiple Range Test (DMRT). vironmental conditions at seed ripening have been shown to affect seedcoat thickness and composition, which could directly affect scarification time. In any case, these data suggest that balloonvine could persist for an undetermined length of time, once in the soil. This is supported by Heit (4) who showed that balloonvine seed could persist in soil for 6 years. Oxygen As the oxygen content increased from 0 to 21 percent, germination of balloonvine seed increased 36 percent, table 2. Scarified balloonvine seed germination, however, was doubled as oxygen increased from 21 to 100 percent. This increase was not likely because of seedcoat limiting oxygen intake; however, oxygen has been shown to increase germination by decreasing inhibitor concentrations by oxidation. These data imply that germination of balloonvine seed generally occurs in the surface few inches, 1 or 2 inches in coarse textured soils and the top inch in heavier clays. TABLE 2. EFFECT OF OXYGEN LEVELS ON BALLOONVINE GERMINATION AFTER THREE DAYS Oxygen Pct. 21 .......................................................... 36b 100 ........................................................... 74c 'Means followed by the same letter are not significantly different at the .05 probability level (DMRT). 0 Germination Pct. Oa' . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Moisture Stress Germination of soybean seed was reduced from 98 percent at 0 bars osmotic potential to 26 percent at -2 bars and 6 percent or less at -4 to -8 bars, respectively. Balloonvine seed, however, were even more sensitive to moisture stress with no germination occurring at osmotic potentials of -2 bars and less, table 3. When balloonvine seedcoats were removed 14 TABLE 3. ALABAMA AGRICULTURAL EXPERIMENT STATION EFFECTS OF MOISTURE STRESS ON BALLOONVINE AND SOYBEAN GERMINATION Osmotic potential Bars 0 -2 -4 -6 -8 0 -2 -4 -6 -8 ................ .................. .................. .................. .................. .................. .................. .................. .................. .................. 0 .................. -2 .................. -4 -6 .................. .................. Germination Day 1 Day 3 Day 5 Day 7 Pct ...... .................... .............. ......... Soybean 98a 98a 96a 49a' 26b 12b 20b Ob 6c Ob 3c 5c Id 1c Id Ob ld Id Ob lc Balloonvine 29a 21a 27a 5a Ob Ob Ob Ob Ob Ob Ob Ob Ob Ob Ob Ob Ob Ob Ob Ob Naked balloonvine 92a 78b 74b 29c - Germination -8 'Means within a column and within a species followed by the same letter are not significantly different at the .05 probability level (DMRT). and naked embryos exposed to the solutions, germination occurred at all levels of osmotic stress. Germination of naked embryos decreased from 92 percent at 0 bars to 15 percent at -8 bars. The extreme sensitivity of balloonvine to moisture stress appears to be an effect of the seedcoat rather than a physiological requirement of the embryo. The seedcoat or embryo could contain an inhibitor(s) which leaches out under favorable moisture conditions but remains in the seed when placed in a non-leaching condition, such as decreased osmotic potential solutions. These data certainly suggest that balloonvine will be more a problem in soils containing abundant surface moisture, such as those in the Black Belt area and bottom soils in the Gulf Coast area and those along rivers and other surface water sources. Similarly, sprinkler irrigation may increase balloonvine weed problems. Temperature Optimum balloonvine seed germination occurred at 95°F. On day 2, germination at 770, 86 ° , and 104°F was similar, but by day 3, each 10°F increase in temperature from 590 to 95°F increased germination, while a 10°F increase in temperature above 95°F by day 4 reduced germination to that obtained at 68°F, table 4. Germination of balloonvine seed in Alabama could, therefore, occur from early April through September, .................. - 15d - - BALLOONVINE-BIOLOGY AND CONTROL 15 TABLE 4. EFFECT OF TEMPERATURE ON BALLOONVINE GERMINATION Germination Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 F ............................ Pct .. .......................... 59 ............ Oa' 2a 4a 4a 5a 5a 68 ............ 4b 7b 15b 17b 18b 19b 77 ............ 14c 22d 26c 27c 27c 29c 86 ............ 22c 45e 50d 54d 56d 56d 95 ............ 43d 60f 61e 65e 69e 70e 104 ............ 11e 13c 15b 15b 17b 17b within columns followed by the same letter are not significantly different at the .05 probability level (DMRT). Temperature 'Means with maximum germination during the warmer summer months. This suggests that balloonvine would be more a problem with late planted soybeans or vice versa with early planted soybeans. Growth and Development Plantingdepth Soybeans and balloonvine did emerge when planted at a depth of 43/4 inches; however, maximum emergence occurred at the 1/3- and 1-inch depths in both soil types, table 5. The two soils in this study, a sandy loam and clay, did not cause a differential response to depth of planting, hence data were combined. Each increase in depth of planting beyond 1 inch reduced soybean emergence; balloonvine emergence at 1 and 21/3 inches was similar. Balloonvine emergence at a depth of 1/3 to 31/2 inches was substantially lower than that obtained with soybeans. These data indicate that soybeans can emerge faster than balloonvine and establish a competitive advantage. However, plants that emerge from deep in the soil TABLE 5. BALLOONVINE AND SOYBEAN EMERGENCE AS AFFECTED BY PLANTING DEPTH Planting depth In............. 1/3 ................ 1 ................ 2 1/3 ............... 3 1/2 ............... 43/4 ............... Day 2 Oa' Oa Oa Oa Oa Emergence Day 4 Day 6 ............... Pct.. ......................... Balloonvine 3a 23a 2a 16a Oa 10b Oa Oc Oa Oc Day 8 27a 2lab 17b 2c lc 1/3 ............... la 1 ............... Oa 2 1/3 ................ Oa 3 1/2 ............... Oa Oc 43/4 ............... Oa Oc within a column and within a species followed by significantly different at the .05 probability level (DMRT). Soybean 77a 78a 23b 89a 84a 57b 11c Od 91a 87b 60b 20c 'Means ld the same letter are not 16 ALABAMA AGRICULTURAL EXPERIMENT STATION (to 43/4 inches) are less likely to be controlled with preemergence applied herbicides, especially those primarily absorbed by the roots. Balloonvine escapes will then have to be controlled with additional weed control inputs. Soil pH Both balloonvine and soybean growth were affected by soil pH. Reduced growth of soybeans occurred at pH 4.9 in Trial II, table 6. However, balloonvine was more sensitive, having reduced growth at pH 5.9 (Trial I) and pH 6.3 (Trial II). These data may help explain why balloonvine is more prevalent in the Black Belt soils since many of these soils are alkaline in nature. Likewise, Alabama's Coastal Plain soils generally have pH levels below 6.9, where balloonvine grew best. TABLE 6. BALLOONVINE AND SOYBEAN GROWTH AS AFFECTED BY SOIL PH 1 Relative yield Balloonvine Soybeans Trial 1 5.9 ............................. 78a 85a 6.3 ............................ 94b 93a 6.9 ............................. 100b 100b Trial 2 4.9 ............................. 18a 41a 5.9 ............................. 36b 89b 6.3 ............................. 42b 94b 6.9 ............................. 100c 100b 'Means within a column followed by the same letter are not significantly different at the .05 probability level (DMRT). Soil pH Soil P and K Balloonvine and soybean plants responded similarly at low (13 pounds per acre) and medium (42 pounds per acre) levels of P, and with 100 percent relative yield for both at the medium level, table 7. The high P level (73 pounds per acre), however, reduced balloonvine growth but did not affect soybeans. Soybean response to K levels was greater than balloonvine. Maximum relative yield of soybeans occurred at the medium K level (39 pounds per acre) while balloonvine produced maximum relative yield at the low K level (16 pounds per acre). The high level of K (140 pounds per acre) reduced yield of balloonvine the same as the high P level. These inhibitory responses cannot be explained. It appears that manipulating soil P and K levels would be of no value in trying to combat this weed. It is doubtful that P could be manipulated anyway since the majority of soils in Alabama are medium to BALLOONVINE-BIOLOGY AND CONTROL TABLE 17 7. INFLUENCE OF SOIL P AND K LEVELS ON BALLOONVINE AND SOYBEAN GROWTH Soil test level Lb./acre Relative yield Relative yield Balloonvine Soybean Phosphorous 77a 79a 13 ............................ 100b 100b 42 ............................ 94ab 80a 73 ............................ Potassium 67a 83a 16 ........................... 90b 100a 39 ............................. 100b 55b 140 ........................... within the same column for an element followed by the same letter are not significantly different at the .05 probability level (DMRT). 'Means high in P already, and a significant change would take many years. If the reduced growth of balloonvine to high levels of P and K was not an anomaly, then perhaps maintaining soil P and K levels in the high range might be of some benefit. Biology Planting of scarified balloonvine seed on biweekly intervals from early April through September during 1977 and 1978 showed that emergence was initially slow, table 8. The April plantings required 9 to 15 days for five balloonvine plants to emerge during the 2-year period. As temperatures warmed, emergence time was reduced to 4 to 7 days, beginning with the last planting date in May and continuing through the same planting date in September. Plant growth, as measured by height 5 weeks after planting, was greatest for the June through July plantings. Flowering appeared to be day-length responsive. The average number of days to first flower was 49, 46, 38, 35, 27, and 27 for plantings made in April, May, June, July, August, and September, respectively. Balloonvine seed production decreased from 14,980 per plot (5 plants) in 1977 and 13,020 in 1978 for the initial plantings to zero for the August 29, 1977, and September 11, 1978, plantings. This means that control of balloonvine will generally need to last through August to prevent soybean seed contamination with balloonvine seed. These data also show that balloonvine is well adapted for growth and reproduction in the Southern States. TABLE 8. GROWTH RESPONSE OF BALLOONVINE TO PLANTING DATES, AUBURN UNIVERSITY AGRONOMY FARM, 1977-78 Planting___date Planting date 1978 __ of five plants Emergence First flowering 1977 1977 4/11 4/25 5/09 5/23 6/06 6/20 7/04 7/18 4/10 4/24 5/08 5/22 6/05 6/19 7/03 7/17 ............. 9b' 10a 8c 7d 7d Sf 5f Sf 1978 1977 1978 Days after planting............ Plant height 5 weeks after planting (in.) 1977 1978 Seed produced per 5 plants 1977 1978 LII- 15a 13b 15a 4f 6de 6de 6de 7d 35 42 56 49 42 35 35 35 28 63 54 46 33 38 38 38 31 4f 4tg 6ef 8de lib 12b 17a 13b 2ef 4ef 4ef l3bc 14b 17a l3bcd 14b 14,890a 16,260a 12,750b - 13,020a 12,500a 11,450ab r OD C) m em 10,350ab 9,2l0bc 6,490cd 5,840d 4,410d 8/01 8/OS 8/29 9/12 9/26 7/31 8/14 8/28 9/11 9/25 Sf 4g 6e Sf 6de 6de 6de 2826 28 28 - 26 24 - 8cd 18a l0bc l2bcd llcd l0cd 7,700c 5,230d 3,740d 1,930e 270e 160e Ge 720e 480e Se 29 4fg 2g Se Ge Ge 320e 7d 12c Ge Ge r 2f 'Means within a column followed by the same letter are not significantly different at the OS5 probability level (DMRT). x m m z --I 0 z BALLOONVINE-BIOLOGY AND CONTROL 19 Competition With Soybeans No significant competitive differences were apparent among balloonvine densities when soybeans were planted in 24-inch rows (by regression analysis). Balloonvine competition was evident in some cases when soybeans were planted in 36-inch rows. Since differences were only slight, data are presented in tabular form, table 9. The number ofballoonvine seed contaminating harvested soybeans was generally the same regardless of the number of balloonvine plants per 33 feet of row. However, the number of balloonvine seed found in a soybean sample could only be used to estimate the number of balloonvine seed produced since some seed had shattered before soybean harvesting. In all cases where balloonvine infested a plot, soybeans were contaminated with balloonvine seed. It is evident from these data that the major problem is soybean seed contamination, and balloonvine competition can be eliminated by planting in rows spaced 24 inches instead of the conventional 36 inches. TABLE 9. INFLUENCE OF BALLOONVINE PLANT DENSITY AND Row SPACING ON SOYBEAN YIELD AND BALLOONVINE SEED CONTAMINATION Ballo.onvnfdniyrobseed Balloonvine density per 33 ft. of row 24-in. rows 0 .............. 2 .............. 4 .............. 8 .............. 16 .............. 32 .............. 40 .............. Soybean yield/acre 1977 1979 Bu. 39a 1 41a 38a 37a 37a - per lb. soybean 1977 1979 0 3 3 4 19 - Bu. 40b 49a 45ab 44ab 44ab 44ab 45ab 0 6 6 6 7 7 3 36-in. rows 0 .............. 2 .............. 4 .............. 8 .............. 16 .............. 31a 28a 31a 28a 25a - 40a 39a 37a 35a 35a 36a 36a 0 8 9 23 49 - 0 3 5 7 9 5 5 within a row spacing and within a column followed by the same letter are not significantly different at the .05 probability level as judged by DMRT. 'Means 32 .............. 40 .............. Herbicide Evaluation Soil-applied Herbicides Metribuzin provided the best control of balloonvine in 1977 and 1979, appendix table 4. Linuron generally provided acceptable control, while control with vernolate was marginal. In both years, balloonvine control showed a trend for higher 20 ALABAMA AGRICULTURAL EXPERIMENT STATION control where balloonvine seed were planted at the 2Va-inch depth. Soybean injury from metribuzin was less when applied preemergence versus preplant incorporated. Control was not complete for any soil-applied herbicide, suggesting that additional measures are needed to control balloonvine escapes. Foliar Applications: Herbicides, Rates, and Times of Application Acifluorfen provided the best control of balloonvine in both Post Test I and II, appendix tables 5 and 6. Linuron, 2,4-DB, metribuzin, and oxyfluorfen provided greater than 70 percent balloonvine control when applied postemergence (Post Test I). Control was more effective when application was made to 3- and 7-inch-tall balloonvine than when applied to balloonvine 18 and 26 inches tall. Foliar Applications: Acifluorfen and Bentazon Rates and Frequency Multiple applications of bentazon (Post Test V) applied over-the-top failed to control balloonvine at any rate or frequency, appendix table 7. However, multiple acifluorfen applications (Post Tests IV, VI, VIII) provided excellent balloonvine control with minimal soybean injury, table 10. Acceptable control, however, was obtained only when balloonvine seed were not found in the harvested soybeans. During 1978 (Post Test IV), when favorable weather conditions existed for postemergence applied herbicide activity, two acifluorfen applications at 1 pound per acre provided complete control. Results were less favorable in 1980 (Post Test VII) under the droughty conditions which also depressed soybean yields. Soybean yields were only occasionally adversely affected by acifluorfen. Herbicide Systems Visual evaluations and balloonvine seed counts showed that vernolate and metribuzin were the most effective preemergence applied treatments for both years, with 1979 results generally better than 1980. However, all these herbicides failed to provide complete control, tables 11 and 12. Control was markedly increased when postemergence applied treatments were included with the preemergence herbicides. Complete balloonvine control was accomplished with the following herbicide systems and should be considered by producers: TABLE 10. EFFECTS OF MULTIPLE ACIFLUORFEN APPLICATIONS ON BALLOONVINE CONTROL, SOYBEAN YIELD, AND BALLOONVINE SEED CONTAMINATION, E. V. SMITH RESEARCH CENTER, 1978-19801 Treatment Times Weedy check .. Hand-hoed check 74................ 7................ Ratesisua active 3 Balloonvine control 1978 1979 1980 Lb/lacre........... Pct........... Oi' Oe Og lO10a 94ahc lOOa 0.25 lOhi 90a-d 7lde 0.5 45c-g h 8c 85cd 9ab G5ef II- -nasonvin -D,-l I -- - Soybean injury 1978 1979 1980 ......... Pet............. 0 Oc Oh 0 3bc Oh 0 3bc 9ab 03c 0 3bc Bb 5ab seed count 1979 1980 ...... No/acre ......... 74,291a 28,826a 526b Oc 2,146b 5,lS2hc 5,8b,5e 4,818b 15,061b 0.5 29d-i 90a-d 90abc 0 Oc 20a 2,955b 1,012c 14................ 28d-i 90a-d 93abc 0 3bc liab 1,053b 3,7G5hc 14................ 0.75 3bc Oh 526b 1,336e 14................ 1.0 35d-h 95abc 93abc 0 3hc 8ab 7,490b 9,lO9hc 28................ 0.5 l3ghi 79d 55f 0 28 ............... . 1.0 1Sf-i 91a-d 78h-e 0 Oc 6ab 1,741b 12,348bc 7; 11............. 0.25 75abc 87a-d 86a-d 0 Oc 8ab Oh 5,506hc 7; 15............. 0.25 33d-i S6bcd 9labc 0 Oc l~ah 2,389h 2,470he 14; 18............. 0.25 S0c-f 88a-d 88a-d 0 5abc 5ah 1,336b 4,l3Ohc 0.25 23e-i 85c-d 81h-e 0 3hc Oh 3,482b 6,032hc 14; 22............. 14;18............. 0.5 95a 98ah 93ahc 0 9ab Oh 2,713hc 14; 22............. 0.5 7labc 92a-d 87a-d 0 3bc l5ab Sl0b 810c 14; 26............. 0.5 T6ahc 95abc 95ah 0 Oc i~ab 1,862b 1,053c 14; 30............. 0.5 GObcd 96ahc lO0a 0 4abc l0ab 1,053b Oc 14;18............. 1.0 lO0a 99a lO0a 0 5abc l9ab Oh Oc 14; 22............. 1.0 93a 98ab 9lahc 0 9ab 3ah Oh 283c 14; 26............. 1.0 88ah 98ab 93abc 0 5abc i~ab Oh 1,053c 14; 30............. 1.0 93a 99a 99a 0 3bc i~ab Oh 65c 7; 11; 15.......... 0.25 9Oab 94abc 76cde 0 5abc Gab 3,07Th 9,757bc 14; 18; 22......... 0.25 70ahc 91a-d 87a-d 0 3bc l4ah Oh 2,Sl0hc 14; 18; 2G......... 0.25 S0c-f 91a-d lOOa 0 9ab i~ab 1,33Gb Oc 14; 22; 2G......... 0.25 S4cde 95a-c 90ahc 0 5abc 4ah 1,053b 4,858bc 'Plots were not cultivated. 'Evaluations made at soybean nmaturity just before harvest. 'Rates used for each treatment. 4 Days after balloonvine emergence. 'Means within a column followed by the same letter are not significantly different at the .05 probability level (DMRT). lha Soybbean yield 1979 1980 Bulacre .. . .... 11 25a-dI 7e 32a 12a-d 22d lla-d 2a- ,d 12a-d 23hc14........02 1 lla-d 29a-d 1 9b-e 27a-d ha-d l0a-d 28a-c l0a-d 25a-d I 26a-d 3 lla-d 24a-dI 12a-d 8 2 a-d1 l10a-d 3Oah4 oc l3ah 3Oah' oc 14a 29a-d lla-d 28a-d 8de 23cd 8de l3ah 28a-d 25a-dI l2a-d I 12a-d 28a-df 26a-d I 9b-e 24a-dI l0a-d 12a-d 27a-d 26a-d 1 lla-d 3lab l3ah 29a-d 0 0 z z 0 m C) cI cI z C) z I- -a 0 cI cI -a -1 1l1la-d N TABLE 11. BALLOONVINE CONTROL AS AFFECTED BY HERBICIDE SYSTEMS VISUALLY EVALUATED IN OCTOBER, E.V. SMITH RESEARCH CENTER, 1979-1980 Preemergence treatment 1 Postemergence treatment None Vernolate Metribuzin Linuron Oxyfluorfen 1979 1980 1979 1980 1979 1980 1979 1980 1979 ............... .. .............. Pct. ..... . ............................. 2 None .............................................. 93ab Hand-hoed Og 75abc 83abc 64cd 5e . . . . 78a-d 47d 35f 65bcd 38ef Hand-hoed......................................93ab 75abC -- 1980 wt 40d - Acifluorfen Acifluorfen Acifluorfen Acifluorfen Acifluorfen Cultivated (POT (POT (POT (POT (POT ....................................... E) E); E); E); E); .............................. acifluorfen (POT L) ...........metribuzin + 2,4-DB (PDS) ... linuron + 2,4-DB (PDS) .......oxyfluorfen (PDS) .............. ........... 63cd - . . 77abc - 63cd 88abc 99a 99a 100a 100a 100a - - 100a 95a 98a 100a 98a - - 83abc 100a 100a 100a 100a -- - 84abc 92ab 95a 96a 96a - - 71bcd 9lab 84abc 96a 98a 100a 100a 100a 98a 98a - - 86ab 95ab 99a 97a 97a - - 99a 95a_ 100a 99a 99a -C - - 0 Acifluorfen (POT E) Acifluorfen (POT E); acifluorfen (POT L) ........... .97a 86abc 'Plots were not cultivated except for the cultivation treatment. 2Means within a year followed by the same letter are not significantly different at the .05 probability level (DMRT).X SPOT E = over-the-top, early; POT L = over-the-top, late; PDS = post-directed spray. I-" m m m z -i z w z TABLE 12. BALLOONVINE SEED CONTAMINATING HARVESTED SOYBEANS AS AFECTED BY HERBICIDE CONTROL SYSTEMS, E. V. SMITH RESEARCH CENTER, 1979-1980 Postemergence treatment None Vernolate Preemergence treatment' Metrihuzin Linuron Oxyfluorfen m 0 0 C) 1979 1980 1979 1980 1979 1980 1979 1980 ............................................ No.lacre ................................... None ..................... Hand-hoed ................ Cultivated................. 1979 - 1980 - 84,494a2 3,441de 17,652de 16,154ab Ob 1,972ab 6,356de - 13,239ab - 8,785de - 2,105b - 73,563ab - 2,591b - 50,972bc5,506b Oh 526b 397h Oh 891h - z C) 7,287de 931b 4,089de 15,10lde 397b Oe Ob Acifluorfen (POT E)3 ...... Acifluorfen (POT E); 2,065e Oh Oh 4,737de Ob Oe Oe acifluorfen (POT L) ....... Acifluorfen (POT E); metribuzin + Oe Oe 26,640a Oh Oh Oe Oe 2,4-DB (PDS)............. Acifluorfen (POT E); Oh Oe 344h Oe Oh Oe Oe linuron + 2,4-DB (PDS) Acifluorfen (POT E); Oe Oh Oe Oe Oh Oh Oe oxyfluorfen (PDS).... 526h 16,721de Acifiuorfen (PUT E)......... Acifluorfen (POT E); 3,603h Oe acifluorfen (POT L)... 'Plots were not cultivated except for the cultivation treatment. 'Means within a year followed hy the same letter are not significantly different at the .05 prohahility level (DMRT). 'POT E= over-the-top, early; POT L = over-the-top, late; PDS= post-directed spray. z -I 0 r- 24 ALABAMA AGRICULTURAL EXPERIMENT STATION System 1: vernolate-preplant incorporated; acifluorfenpostemergence over-the-top early; acifluorfen postemergence over-the-top 2 to 3 weeks after the first application; System 2: same as System 1 except for a second postemergence application of metribuzin + 2,4-DB post-directed; System 3: same as System 1 except for a second postemergence application of linuron + 2,4-DB post-directed; System 4: same as System 1 except for a second postemergence application of oxyfluorfen + 2,4-DB post-directed; System 5: metribuzin-preemergence; acifluorfen-postemergence over-the-top early; acifluorfen-postemergence over-the-top 2 to 3 weeks after the first application; System 6: same as System 5 except for a second postemergence application of metribuzin + 2,4-DB post-directed; System 7: same as System 5 except for a second postemergence application of linuron + 2,4-DB post-directed; System 8: same as System 5 except for a second postemergence application of oxyfluorfen + 2,4-DB post-directed. The choice of one of the above systems will depend on cost, application capabilities, and soil type. Vernolate will generally be a better choice for coarse textured soils, while metribuzin will fit more on medium to fine textured soils. Over-the-top broadcast applications are easier and faster, but more costly. Post-directed applications are generally cheaper but more time consuming. The chemical intensity of these systems may be reduced with the addition of cultivation. Cultivation alone reduced balloonvine contamination by 79 percent in 1979 and 34 percent in 1980 when compared to the untreated check, table 12. Soybean injury ratings showed little differences among herbicide systems, with crop injury of 31 percent or less, table 13. Injury of 30 percent or less is only slight injury. Soybean yields in both years generally were not different from the hand-hoed treatment. Also, yields generally were not different from the untreated check. This again points out that balloonvine is not highly competitive with soybeans. Yields for 1980 were low because of dry weather, table 14. 0 z TABLE 13. SOYBEAN INJURY TO HERBICIDE CONTROL SYSTEMS VISUALLY EVALUATED IN OCTOBER, E. V. SMITH RESEARCH CENTER, z I-" IO 1979-1980 Postemergence treatment None 1979 1980 ......................................... 2 Ob Oe 3ab Ob Vernolate 1979 1980 14ab - None ..................... Hand-hoed Cultivated Preemergence treatment' Metribuzin Linuron 1979 1980 1979 1980 ..... Pct.............. ......... ..... 4cde 20ab 4cde Ob 5cde - Oxyfluorfen 1979 1980 ....... ....... 4ab 8cde - 0 z ............... ................ 13b-e 13b-e - - Acifluorfen (POT E)3 ....... -10ab Acifluorfen (POT E); acifluorfen (POT L) Acifluorfen (POT E); metribuzin + 2,4-DB (PDS) ........... Acifluorfen (POT E); linuron + 2,4-DB (PDS) . Acifluorfen (POT E); oxyfluorfen (PDS) ....... Acifluorfen (POT E) ........ 5ab 8ab 0 z 0 Oe - 5ab 14ab 16ab 9ab 15ab - 3de 18a-e 26abc 3lab 14b-e - 3ab 13ab 9ab Ob Ob - 6cde 13b-e 39a 26abc 9b-e - 5ab 25a 16ab 19ab 15ab 21a-e 9b-e 19a-e 14b-e llb-e - 14ab 19ab 1lab 3ab - 9b-e 23a-e 15b-e 3de - 24abc lObed Acifluorfen (POT E); acifluorfen (POT L) ..... 'Plots were not cultivated except for the cultivation treatment. 2 Means within a year followed by the same letter are not significantly different at the .05 probability level (DMRT). 3 POT E = over-the-top, early; POT L = over-the-top, late; PDS = post-directed spray. Cu TABLE 14. SOYBEAN YIELD RESPONSE TO HERBICIDE CONTROL SYSTEMS, E. V. SMITH RESEARCH CENTER, 1979-1980 Vernolate 1979 1980 1979 1980 ................................................ None...................... 27ab' 6c 26ab l2ab 29ab 14a Rand-hoed................ ...... 31a l3ab Cultivat d ......... 4 35a 15a Acifluorl n (POT E) Acifluorfen (POT E); 18b l3ab acifluorfen (POT L) ..... Acifluorfen (POT E); metribuzin + 25ab l3ab 2,4-DB (PDS).............-Acifluorfen (POT E); -30ab l4ab linuron + 2,4-DB (PDS) Acifluorfen (POT E); 26ab 15a oxyfluorfen (PDS)......... ilab Acifluorfen (POT E)........ 28ab Acifluorfen (POT E); 27ab l2ab acifluorfen (POT L)... Postemergence treatment None' Preemergence treatment' Metribuzin Linuron 1979 1980 1979 1980 Bulacre......................................... 25ab l3ab 32a l3ab - Oxyfluorfen 1979 1980 31a - l4ab - 28ab 25ab 30ab 26ab 3Oab - l3ab l2ab ilab ilab l2ab - 35a 23ab 31a 32a 32a - l2ab l2ab 9bC l0ab l4ab - 33a 23ab 29ab 34a 26ab - l3ab 15a l2ab liab l3ab - 0 c r- ''Yieldswere expressed at 11except formoisture. Plots are not cultivated percent the cultivation treatment. x M m z -I I Co) 'Means within a year followed by the same letter are not significantly different at the .05 probability level (DMRT). 4 POT E = over-the-top, early; POT L = over-the-top, late; PDS = post-directed spray. 0 z BALLOON VINE-BIOLOGY AND CONTROL 27 SUMMARY Balloonvine biology and control experiments were conducted from 1977 to 1980 to identify germination, growth, and reproductive characteristics; determine competitive effects with soybeans; and evaluate methods of control in soybeans. Balloonvine seed, considered to be 100 percent hard seeded, needed 3 hours of harsh scarification with concentrated sulfuric acid to germinate. Also, adequate levels of moisture and oxygen were needed in the immediate environment for germination. All of these factors lead to the conclusion that persistence of balloonvine once introduced into a field is very likely. Balloonvine was able to grow well under conditions favorable for soybean production. However, soybeans can obtain a competitive edge over balloonvine because of their rapid emergence. Balloonvine was not found tobe competitive with soybeans even at densities of 40 plants per 33 feet of row. Balloonvine was found to be sensitive to the soil-applied herbicides vernolate, metribuzin, and linuron, and foliarapplied herbicides acifluorfen, metribuzin, linuron,; and 2,4-DB. Applications of acifluorfen (POT) were most effective when made approximately 2 weeks after balloonvine emergence. Since balloonvine emerge and produce seed through August, emerge from depths to 4/ inches, and potentially have longevity in the soil, systems providing season-long control are needed. This was provided by soil treatments of vernolate or metribuzin followed by acifluorfen (POT) and either metribuzin + 2,4-DB or linuron + 2,4-DB (PDS). A timely cultivation should further lengthen control. 28 ALABAMA AGRICULTURAL EXPERIMENT STATION LITERATURE CITED (1) (2) F. L., R. H. CROWLEY, and L. R. OLIVER. 1981. Soybean Update. Ark. Coop. Ext. Ser. Univ. of Ark. Cir. AGR 11, 3pp. BALDWIN, GOODMAN, GEORGE J. 1974. Proc. Oklahoma Acad. Sci. 54:98-99. HEIT, C. E. 1974. Germination and Hard Seed Studies with C. halicacabum (Balloonvine, Heartseed) in Laboratory Testing. Newsl. Assoc. Off. Seed Anal. 48:35-37. JOHNSTON, S. K., R. H. CROWLEY, AND D. (3) (4) (5) S. MURRAY. 1978. Separating Seed by Species with CaC12 Solutions. Weed Sci. 26:213-215. JOHNSON, S. K., D. S. MURRAY, AND J. C. WILLIAMS. 1979. Germination and Emergence of Balloonvine (Cardiospermumhalicacabum).Weed Sci. 27:73-76. (6) MOHR, C. 1901. Plant Life in Alabama. Contrib. U.S. Nat. Herb. V.II. 608 pp. (7) (8) RADFORD, A. E., H. E. AHLES, AND C. R. BELL. 1968. Manualof the Vascular Flora of the Carolinas. Univ. of N. C. Press, Chapel Hill, p. 691. J. E., D. S. MURRAY, S. K. JOHNSTON, AND R. H. CROWLEY. 1978. Balloonvine Growth and Control with Postemergence Applied Herbicides. Proc. South. Weed Sci. Soc. 23:54-62. STREET, BALLOON VINE-BIOLOGY AND CONTROL 29 2 APPEN DLX APPENDIX TABLE 1. TRADE, COMMON, AND CHEMICAL NAMES OF CHEMICALS MENTIONED IN THIS BULLETIN Trade name Amiben ......... Basagran ........ Blazer 2L ....... Common name chioramben bentazon acifluorfen Chemical name 3-amino-2,5-dichlorobenzoic acid 3 -isdpropyl-JH-2,1,3-henzothiadiazin4(3H)-one 2,2-dioxide 5-[2-chloro-(4-trifluormethyl)phenoxy]2-nitrobenzoic acid 4-(2,4-dichlorophenoxy) hutyric acid 4 N ,N4 -diethyl-a,ar,a-triflluoro-3,5dinitrotoluene-2,4-diamine bromomethane 2-sec-butyl-4,6-dinitrophenol + N=-naphtylphthalamic acid 2,3-dihydro-2,2-dimethyl-7henzofuranylmethyl carbamate 2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4(trifluorom ethyl) benzene Butyrac 200..2,4-DB (amine salt) Cobex..........dinitramine Dowfume ....... Dyanap ......... methyl bromide dinoseb + naptalam Furadan......... carbofuran Goal ............ Lasso ........... Lexone, Sencor Lorox oxyfluorfen alachlor .. metribuzin ........... linuron Paraquat CL..paraquat Premerge3 .. dinoseb Prowl ........... pendimethalin Ronstar.........oxadiazon Sevin ........... carbaryl Surfian .......... oryzalin Tenoran......... chloroxuron Treflan..........trifluralin Vernam ......... vernolate 2-chloro-2',6'-diethyl-N-(methoxymethyl) acetanilide 4-amino-6-tert-butyl-3-(methylthio)-astriazin-5(4H)-one 3-(3,4-dichlorophenyl)-1-methoxy-lmethylurea 1,1'-dimethyl-4,4'-hipyridinium ion 2-sec-butyl-4,6-dinitrophenol N-(1-ethylpropyl)-3,4-dimethyl-2,62-tert-butyl-4-(2,4-dichloro-5isoproproxyphenyl)-2-1,3,4oxadiazolin-5-one 1-naphthyl-N-methylcarbamate 3,5-dinitro-N4,N 4 -dipropylsulfanilamide 3-[p-(p-chlorophenoxy)phenyl]-1,1a,a,a-trifluoro-2,6-dinitro-N, N-dipropylp-toluidine S-propyl dipropylthiocarbamate 30 ALABAMA AGRICULTURAL EXPERIMENT STATION APPENDIX TABLE 2. TREATMENT SCHEMES EVALUATED FOR FREQUENCY OF ACIFLUORFEN (POST TESTS IV, VI, VII) AND BENTAZON APPLICATIONS (POST TEST V), 1978-1980 Time-days after balloonvine emergence application 1st 2nd 3rd 7 14 28 - - Rates' Post Tests IV, VI, VII acifluorfen Lb. active/acre 0.0, 0.25, 0.5 0.25, 0.5, 0.75, 1.0 0.5, 1.0 Post Test V bentazon Lb. active/acre 0.5, 1.0 0.5, 0.75, 1.0,1.5 0.75, 1.5 7 7 14 14 14 14 14 14 14 14 14 14 11 15 18 22 18 22 26 30 18 22 26 30 0.25 0.25 0.25 0.25 0.5 0.5 0.5 0.5 1.0 1.0 1.0 1.0 0.5 0.5 0.5 0.5 0.75 0.75 0.75 0.75 1.0 1.0 1.0 1.0 - - 7 11 15 0.25 0.5 22 0.25 0.5 14 18 14 18 26 0.25 0.5 0.5 22 26 0.25 14 'All treatments contained a nonionic spray adjuvant at 0.25 percent v/v. w arAPPENDIX TABLE 3. HERBICIDE CONTROL SYSTEMS EVALUATED FOR BALLOONVINE CONTROL IN SYSTEMS TESTS I AND II 0 0 PPI Vernolate Vernolate .... ........- PRE - Early POT Treatments' Late POT - z Z m 0 0 O- Early PDS Rates Lb. active/acre Acifluorfen Vernolate Vernolate Vernolate Vernolate ........ ........................Metribuzin Acifluorfen Acifluorfen Acifluorfen-Metribuzin Acifluorfer Acifluorfen - - + 2,4-DB Linuron + 2,4-DB Oxyfluorfen - Metribuzin Metribuzin Metribuzin Metribuzin Metribuzin Linuron Acifluorfen Acifluorfen Acifluorfen Acifluorfen Acifluorfen - Acifluorfen - Metribuzin + 2,4-DB Linuron + 2,4-DB Oxyfluorfen - 2.5 2.5; 0.5 2.5; 0.375; 0.375 2.5; 0.5; 0.25 + 0.25 2.5; 0.5; 0.5 + 0.25 2.5; 0.5; 0.25 0.375 0.375; 0.5 0.375; 0.375; 0.375 0.375; 0.5; 0.25 + 0.25 0.375; 0.5; 0.5 + 0.25 0.375; 0.5; 0.25 1.0 C) < 0 Z -I I- 1.0; 0.5 1.0; 0.5; 0.25 + 0.25 Linuron -1.0; 0.5; 0.5 + 0.25 Linuron 1.0; 0.5; 0.25 ...... Oxyfluorfen0.5 ...... Oxyfluorfen Acifluorfen0.5 ...... Oxyfluorfen Acifluorfen Acifluorfen 0.5; 0.375; 0.375 ...... Oxyfluorfen Acifluorfen Metribuzin + 2,4-DB 0.5; 0.5; 0.25 + 0.25 ...... Oxyfluorfen Acifluorfen Linuron + 2,4-DB 0.5; 0.5; 0.5 + 0.25 --...... Oxyfluorfen Acifluorfen Oxyfluorfen 0.5; 0.5; 0.25 - ...... Acifluorfen0.5 ...... Acifluorfen Acifluorfen 0.5; 0.5 'All postemergence applications contained a nonionic spray adjuvant at 0.25 percent vlv; PPI= preplant incorporated; PRE = applied to soil surface immediately after planting; POT= postemergence over-the-top; PDS = postemergence directed. -Linuron ...... ...... - Linuron Linuron Acifluorfen Acifluorfen Acifluorfen Acifluorfen Acifluorfen Acifluorfen Metribuzin + 2,4-DB Linuron + 2,4-DB Oxyfluorfen W' CA) APPENDIX TABLE 4. RESPONSE OF BALLOONVINE AND SOYBEAN TO PLANTING DEPTH AND SOIL-APPLIED HERBICIDES, AUBURN UNIVERSITY AGRONOMY FARM, 1977 AND 1979 Visual rating' arI a Treatment Rate s active Lb.lacre. Alachlor (PRE)................2.0; 4.0 2.0; 4.0 Chloramben (PRE) ............. 0.375; 0.75 Dinitramine (PPI) .............. Dinoseb + naptalam (PRE) Linuron (PRE) 0.375; 0.75 Metribuizin (PPI) ............... Metribuzin (PRE).............. 0.75; 1.5 Oryzalin (PRE)................ Oxadiazon (PRE) ................. 1.0; ... + 1.5 Soybean planting depth Balloonvine planting depth 1977 1979 1977 1979 3/4 21/3 3/4 21/3 3/4 2 1/3 3/4 2 1/3 in. in. in. in. in in. iii in. ............. Pct. control......................Pct. injury............ 44 30 3 13 51 57 36 35 14 55 55 9 4 6 0 0 96 60 61 63 44 61 74 46 40 75 0 C C--I C I- 3.0; 3.0 + 6.0 69 75 57 67 52 71 79 44 24 34 39 43 30 45 2.0 0.5; 1.0 Pendimethalin (PRE) ........... Trifluralin (PPI)............... 0.5; 1.0 Vernolate (PPI)................ 2.0; 4.0 1.0; ............... 1.0; 7,3 94 55 35 95 85 11 56 89 85 9 83 90 87 19 84 28 10 28 33 8 11 20 54 69 51 52 33 58 23 36 14 2.0 2.0 'Ratings 3 24 40 0 56 68 15 18 53 11 26 60 4 1 10 1 23 43 30 45 37 33 30 24 x -v averaged over both herbicide rates. m z -a 0 z BALLOON VINE-BIOLOGY AND CONTROL APPENDIX TABLE 5. CONTROL OF BALLOONVINE WITH POSTEMERCENCE-APPLIED HERBICIDES, E. V. SMITH RESEARCH CENTER,1978 33 3 Herbicide Rates active Lb/acre Acifluorfen3 .......... 0.5; 1.0 Bentazon ............ 0.5; 1.0 Chloroxnron ......... 1.0; 1.5 2,4-DB .............. 0.1; 0.2 Dinoseb.............0.5; 1.0 Dinoseb + naptalam .0.5 + 1.0; 1.0 + 2.0 Linuron ............. 0.5; 1.0 Metribuzin .......... 0.25; 0.5 Oxyfluorfen .......... 0.25; 0.5 averaged over both herbicide rates. 2 Early applications made to 3-inch and late applications made to 15-inch-tall balloonvine. 3 AI1 herbicide treatments except dinoseb and dinoseb + naptalam received a nonionic spray adjuvant at 0.25 percent v/v. 'Ratings Visual rating' Time of application 2 Early Late Early + Late ........................... Pct. control.......... 95 99 9 18 20 44 28 64 83 60 97 36 28 53 13 23 48 77 51 85 77 46 93 78 43 99 91- APPENDIX TABLE 6. RESPONSE OF BALLOONvINE TO POSTEMERCENCE-APPLIED HERBICIDES IN POST TEST LI AND POST TEST III, E. V. SMITH RESEARCH CENTER, 1978-1979 Visual rating-' Herbicide Rates active Lb/lacre 1.0 1.0 Acifluorfen 2 Bentazon..0.75; . .0.5; Chloroxnron .. 1.0; 1.5 2,4- DB...0.05; 0.1 Dinoseb..0.5; 1.0 Dinoseb ± naptalam ... 0.5 + 1.0; 1.0 + 2.0 2 Balloonvine height at herbicide application 3 in. 7 in. 18 in. 26 in. 1978 1979 1978 1979 1978 1979 1978 1979 ........... ............... control ......... ......... Pct. 96 87 70 75 77 51 48 71 15 19 35 11 5 10 10 16 58 20 68 24 21 26 22 23 34 47 43 35 41 36 18 56 18 39 15 16 18 30 27 46 16 36 24 13 26 20 32 36 A11 herbicide treatments except dinoseb and dinoseb + naptalam contained a nonionic spray adjuvant at 0.25 percent v/v. 'Ratings averaged over both herbicide rates. 34 34 ALABAMA AGRICULTURAL EXPERIMENT STATION APPENDIX TABLE 7. EFFECTS OF MULTIPLE BENTAZON APPLICATIONS ON BALLOONVINE, E. V. SMITH RESEARCH CENTER, 1978 Days after balloonvine emergence Weedy check............................. Hand-hoed check .......................... 7..................................... Rates active Lb/lacre - Balloonvine control' 9/08 10/31 Pct. Of 99a 20c-f 35bcd 3ef Sef Pct. 5def 7 ....................................... 14 ....................................... 14 ....................................... 14 ....................................... 14....................................... 28 ....................................... 28....................................... 7; 11 ................................... 7; 15 ................................... 14; 18 ................................... 14; 22 ................................... 14; 18 ................................... 14; 22 ................................... 14; 26 ................................... 14; 30 ................................... 14; 18 ................................... 14; 22 ................................... 14; 26 ................................... 14; 30 ................................... 7; 11; 15 ................................ 14; 18; 22 ................................ 14; 18; 26 ................................ 0.5 1.0 0.5 0.75 85a 23b-f 30b-f Ob 5def 1.0 1.5 0.75 1.5 0.5 0.5 0.5 0.5 0.75 0.75 0.75 0.75 l3def l3def 20c-f 4lbcd 18c-f 20c-f 40bcd 28b-f 43bcd 30b-e 28b-f 43bcd 18b-f lOc-f 3ef 8def 15c-f 23b-f 13c-f 25b-f 35bcd 13c-f 23b-f 15c-f 1.0 1.0 1.0 1.0 0.5 0.5 28b-f 38bcd 28b-f 40bcd 38bcd 48bc 4Obc 48b 15c-f 23b-f 4Obc 8def 4Obc 33b-e 14; 22; 26............................... 0.5 0.5 28b-f 53b 'Means within a column followed by the same letter are not significantly different at the .05 probability level (DMRT). BALLOONVINE-BIOLOGY AND CONTROL 35 ACKNOWLEDGMENT This research was supported by check-off funds provided by Alabama soybean farmers. AUBURN UNIVERSITY WXith an agricultural research unit in every major soil area, Auburn University serves the needs of field Crop, livestock, forestry, and horticultural producers in each region in Alabama. Every citizen of the State has a stake in this research program, since any advantage from new and more economical ways of producing and handling farm products directly benefits the consuming public. Q o 10 > ( ® 2 1 ® Main Agricultural Experiment Station, Auburn. a E. V. Smith Research Center, Shorter. Tennessee Valley Substation, Belle Mina. Send Mountain Substation, Crossville. Norih Alabama Horticulture Substation, Cullman. Upper Coastal Plain Substation, Winfield. Foresiry Unit, Fayette County. Chilton Area Horticulture Substation, Clanton. Forestry Unii, Goose County. Piedmont Subsiation, Camp Hill. Plant Breeding Unit, Tallassee Forestry Unit, Autauga County. Prattville Experiment Field, Prattville. Black Belt Substation, Marion Junction. The Turnipseed-Ikenberry Place, Union Springs. Lower Coastal Plain Substation, Camden Forestry Unit, Barbour County Monroeville Experiment Field, Monroeville. Wiregrass Substation, Headland. Brewton Experiment Field, Brewion. Solon Dixon Forestry Education Center, Covington end Escambia counties. 20. Ornamental Horticulture Field Station, Spring Hill. 21. Gulf Coast Substation, Fairhope. 1 2. 3 4. 5. 6. 7 8. 9 10 11. 12. 13. 14. 15. 16 17 18. 19.