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Дослі-джено морфологічні особливості та онтогенетичний розвиток Cenchrus longispinus. Виділено чотири її життєві періоди. Визначено ознаки, за якими діагностується цей карантинний бу-р'ян та розроблено методику ранньої діагностики засміченості угідь цією рослиною. Дано рекомендації по боротьбі з карантинною рослиною C. longispinus.

During the study of flora of ecotopes of the railway tracks of the Dniester embankment, 14 localities of the North American species Cenchrus longispinus were identified. On the sand the plants are better developed, have more lateral shoots. On crushed stone substrate, especially in the interrail space of the railway, plants are low – 7 (10) cm high. In addition, Cenchrus longispinus on the Dniester embankment was found in areas where no radical transformation of the ecotope (beach) is detected. Problem. The adventive species Cenchrus longispinus (Hack.) Fernald in Ukraine is at the expansion stage. It poses significant potential threat to the environment due to stress tolerance, wide ecological amplitude, high degree of naturalization, significant coenotic activity and so on. Much attention is now being paid to the study of the conditions for the emergence and naturalization of new adventitious species, especially quarantine ones. Cenchrus longispinus originates from North America and is distributed with grain bulks. The species has spread to many countries - it has been found in South Africa, India, Moldova, Russia, in a number of European countries. Навести яких. In Ukraine, the species was first detected in the southern regions. It is a kenophyte, agrio-epecophyte and belongs to the quarantine organisms that are partially distributed in Ukraine (A-2). In the ecological sense, the species prefers arid soil conditions. It is a heliophyte, in ecological and coenotic terms - a psammophyte. Most of its populations are concentrated in anthropogenic ecotopes. Methods. In the summer of 2021, anthropogenically transformed areas of the Dniester embankment were surveyed by a route method. The flora of the railway tracks between the railway stations Karolinа-Bugas and Sonyachna was studied. Results. 14 localities of Cenchrus longispinus were identified. Their coordinates are given in the publication. Plants are mostly localized in areas of unauthorized or organised pedestrian crossings over railway tracks. The substrate is crushed stone of railway tracks or adjacent sandy soil. Conclusions. On sand plants, by sight, are better developed, have more lateral shoots, are higher. On the crushed stone substrate of railway tracks, especially in the interrail space, the plants are low - 7 (10) cm high. Specimens on both types of substrate, even those that undergo moderate and severe mechanical damage by pedestrians, possess a significant number of grown additional shoots. Almost all shoots have developed fruit. Cenchrus longispinus on the Dniester embankment is represented not only in areas with strong anthropogenic impact, but also where human influence is moderate or apparently nonexistent. However, all surveyed areas are visited by pedestrians or vacationers., Резюме Мета. Адвентивний вид Cenchrus longispinus (Hack.) Fernald на території України знаходиться у стадії експансії. Суттєву потенційну небезпеку для довкілля становить завдяки стрес-толерантності, широкій екологічній амплітуді, високому ступеню натуралізації, значній ценотичній активності тощо. Вивченню умов появи та натуралізації нових адвентивних видів, особливо карантинних – нині приділяється значна увага. Cenchrus longispinus, походить в Північної Америки та поширюється із зерновими вантажами. Вид розповсюдився на території багатьох країн – його виявлено у Південній Африці, Індії, Молдові, Росії, низці європейських держав. В Україні вид вперше зафіксовано у південних регіонах. Він є кенофітом, агріо-епекофітом та відноситься до карантинних організмів, що обмежено поширені в Україні (А-2). В екологічному відношенні вид тяжіє до посушливих ґрунтових умов. Є геліофітом, в еколого-ценотичному відношенні – псамофітом. Більшість його популяцій зосереджена на антропогенних екотопах. Методи. Влітку 2021 року, маршрутним методом обстежено антропогенно перетворені ділянки Дністровського пересипу. Вивчали флору залізничних колій між залізничними станціями Кароліна-Бугаз та Сонячна. Результати. Виявлено 14 локалітетів Cenchrus longispinus. В публікації наведено їх координати. Рослини, здебільшого, локалізовані на ділянках самовільних або обладнаних пішохідних переходів через залізничні колії. Субстратом є щебінь колій або прилеглий піщанистий ґрунт. Висновки На піску рослини, візуально, – краще розвинені, мають більшу кількість бічних пагонів, більш високі. На щебенистому субстраті залізничних колій, особливо у міжколійному просторі, рослини низькі – 7(10) см. Екземпляри на обох типах субстрату, навіть при наявності помірного та сильного механічного пошкодження пішоходами – мають значну кількість відрослих додаткових пагонів. Практично всі пагони – з плодами. Cenchrus longispinus на Дністровському пересипі представлений не лише на ділянках із сильним антропогенним навантаженням, але й там, де плив людини помірний, або практично відсутній. Проте, практично всі обстежені ділянки відвідують пішоходи або відпочиваючі.

Fisa descriere si cheie de identificare pentru specia Cenchrus longispinus, Managementul adecvat al speciilor invazive din România, în conformitate cu Regulamentul UE 1143/2014 referitor la prevenirea și gestionarea introducerii și răspândirii speciilor alogene invazive, POIM 2014+ 120008, 2018-2022. http://invazive.ccmesi.ro/

Experiments were conducted to determine the efficacy, absorption, and translocation of nicosulfuron, rimsulfuron, and nicosulfuron + rimsulfuron on barnyardgrass, green foxtail, longspine sandbur, and large crabgrass. In the greenhouse, nicosulfuron, rimsulfuron, and nicosulfuron + rimsulfuron were applied at 0.0625, 0.125, 0.25, 0.5, 0.75, 1, and 2 times their label rates of 35, 13, and 26 + 13 g ai ha−1, respectively, on 5- to 10-cm plants. Three weeks after treatment (WAT), barnyardgrass was the most susceptible species to all three herbicides, and large crabgrass was the least susceptible. The nicosulfuron, rimsulfuron, or nicosulfuron + rimsulfuron rates causing 50% visible injury (GR50) for barnyardgrass were 10.9, 4.8, and 6 + 3 g ai ha−1, respectively. Similarly, the GR50for large crabgrass were 25.6, 9.9, and 14.3 + 7.2 g ai ha−1, respectively, 3 WAT. Absorption of nicosulfuron, rimsulfuron, and nicosulfuron + rimsulfuron was greater in barnyardgrass than in large crabgrass. Absorption of nicosulfuron + rimsulfuron in barnyardgrass and large crabgrass was 74% and 57%, respectively, 7 d after treatment (DAT). In addition, translocation of nicosulfuron, rimsulfuron, and nicosulfuron + rimsulfuron out of the treated leaf was 14, 12, and 14% higher, respectively, in barnyardgrass than in large crabgrass. The differential response of these weed species to nicosulfuron, rimsulfuron, and nicosulfuron + rimsulfuron might be due to differences in herbicide absorption and translocation.

Long-spine sandbur is an annual grass that infests many fields in southwestern Ontario, especially those with sandy soils. Eight field experiments were conducted over a 2-yr period (2007, 2008) in Ontario to determine the efficacy of various preemergence (PRE) and postemergence (POST) herbicides for control of long-spine sandbur in corn. Generally, the POST applied herbicides controlled long-spine sandbur better than PRE herbicides evaluated in this study. PRE application of dimethenamid-p (1250 g a.i. ha-1), S-metolachlor (1600 g a.i. ha-1), flufenacet (1040 g a.i. ha-1), pendimethalin (1680 g a.i. ha-1), pyroxasulfone (250 g a.i. ha-1), or isoxaflutole plus atrazine (105 + 1063 g a.i. ha-1) controlled long-spine sandbur 0-79%. POST application mesotrione + atrazine (140 + 280 g a.i. ha-1) or topramezone + atrazine (18.75 + 500 g a.i. ha-1) provided 24-82% control, foramsulfuron (35 g a.i. ha-1) or primisulfuron/dicamba (26 +140 g a.i. ha-1) provided 54-87% control, and rimsulfuron (15 g a.i. ha-1), nicosulfuron (25 g a.i. ha-1) or nicosulfuron/rimsulfuron (25 g a.i. ha-1) provided 68-95% control of long-spine sandbur in corn. Similar reduction in sandbur density and shoot dry weight were observed. PRE applied isoxaflutole + atrazine and POST applied rimsulfuron, nicosulfuron, nicosulfuron/rimsulfuron, foramsulfuron, primisulfuron/dicamba, and topramezone + atrazine all provided yield comparable with the weed-free control. Among the herbicides evaluated rimsulfuron, nicosulfuron, and nicosulfuron/rimsulfuron provide the most consistent long-spine sandbur control in corn.Key words: Weed control, preemergence herbicide, postemergence herbicide, rimsulfuron, nicosulfuron, foramsulfuron, primisulfuron, dicamba, topramezone, atrazine

An experiment was conducted in 2005 and 2006 in southwestern Ontario to examine the efficacy of imazethapyr application timing on the control of long-spined sandbur in soybean (Glycine max L. Merr.). Imazethapyr (100 g a.i. ha-1) was applied early and delayed preemergence (PRE), and postemergence (POST) at the spike to five-leaf stage of the weed. Soybean was not injured by any treatment. Imazethapyr applied PRE did not control long-spined sandbur; POST treatments resulted in up to 72, 66, 78, 91, 78, and 71% weed control when applied at the spike, one-, two-, three-, four-, and five-leaf stage, respectively, and crop yield increased 44, 28, 39, 24, 38, and 20%, respectively. Therefore, imazethapyr should be applied at the three-leaf stage of the weed to optimize control and crop yield. Key words: Weed control, soybean, preemergence herbicide, postemergence herbicide

Longspine sandbur is a troublesome weed infesting corn in the Great Plains. However, herbicides are now available to control this species. This study characterized longspine sandbur ecology in irrigated corn to aid producers in integrating herbicides into their production systems. Longspine sandbur began emerging May 25, and by June 15, 84% of the seasonal emergence had occurred. Plant development was related to cumulative growing degree days. Seeds were viable early in longspine sandbur's development, with 20% of seeds viable by heading. Producers can minimize seed production of longspine sandbur in field borders by mowing plants at the boot stage. Bur production per plant was related to time of emergence, with seedlings emerging in late May producing 1,120 burs per plant. Seedlings emerging 4 wk later produced 84% fewer burs. Controlling longspine sandbur before 4 wk of interference prevented loss of corn grain yield.

Fall-planted longspine sandbur began to emerge in April, peaked in late April or May, and continued at low levels through October. During the first year after seeding, 98% of the total seedlings emerged prior to June. Fall-planted puncturevine began to emerge in late April or May and continued through October. Puncturevine emergence was multipeaked and 75% of each season's total emerged prior to mid-July. A similar number of puncturevine seedlings emerged the second and third years after planting as in the first. The emergence pattern for a species was similar each year regardless of how long the seed had lain in the soil. Longspine sandbur required 7 to 13 weeks from emergence to heading and produced approximately 2600, 1300, 180, and 3 spikes per plant when planted in May, June, July, and August, respective- ly. Puncturevine flowered within 3 to 4 weeks after emergence when temperatures were favorable and pro- duced an average of 5600, 5200, 3600, and 200 burs per plant when planted in May, June, July, and August, respectively. Nomenclature: Longspine sandbur, Cenchrus longispinus (Hack.) Fern. #3 CCHPA; puncturevine, Tribulus terrestris L. # TRBTE. Additional index words. Planting date, seedling emergence, CCHPA, TRBTE.

Longspine sandbur germinated readily after 3 months of storage at 0 to 4 C. Germination was 15 to 82 and 10 to 76% for seed retained by or that passed through a 1.7-mm-mesh screen, respectively, and was greatest in complete darkness near 30 C. Light inhibited seed germination at most of the temperatures tested. Incubating imbibed seed at 40 C and 40/10 C for 3 weeks reduced the viability of seed that did not germinate by more than 50%. Primary seed within the bur germinated 77% and secondary seed germinated 35% during 2 weeks at 35/10 C (16 light/8 dark h). Primary seed placed in polyethylene glycol (PEG) solutions ranging from −0.5 to −1.5 kPa water potential germinated as much or greater than seed placed in water, while secondary seed germination was inhibited by similar osmotic potentials. Seedlings emerged from depths to 11 cm but emerged most readily from 1- to 3-cm depths.

bluffs less than 1 km. distant. A few species, all rare in this part of the Hudson Valley only a few years ago, have recently increased in abundance on sandy soils near the river from Columbia County southward; these include Strophostyles Jhelvola, Cenchrus longispinus, Mirabilis ?hirsuta, Salsola kali var. tenuifolia, and Triplasis purpurea. In summation, the newly established flora consists almost entirely of species whose immigration into denuded areas might have been expected in this part of New York and in this proximity to roadsides, abandoned fields, railroad embankments, and river marshes. The least-expected species was Epipactis helleborine, which in this part of New York is usually a plant of rich woodlands. As a general conclusion, it may be emphasized that succession on the sand-flats has been retarded except in the limited areas shaded by the clumps of cottonwoods which became established soon after 1930. Even in these clumps, the successional series are still in formative stages, dominated by a few woody vines and by Prunus serotina. No general pattern of succession is yet discernible among the herbaceous species, but it seems probable that in another decade, after formation of significant amounts of humus-containing soil, various additional native woodland species will replace many of the semi-weedy species now present. Succession in treeless areas, where by chance no cottonwood seedlings survived after the first formation of the sand-flats, has not established any recognizable pattern except that it may be presumed that the thickets of Robinia will eventually attain tree size and that these and the thickets of Rhus and Salix will presumably increase in extent and in density and ultimately shade out most of the herbaceous species now growing among them. Decrease in extent of unshaded areas is not apparent at this time (Fig. 6); little or no soil is being formed in them, and no significant increase in the cover has been noted since 1935, although the relative importance of certain species has changed.

Summary: Resume: Zusammenfassung Seed dormancy and germination in sand burr (Cenchrus longispinus (Hack,) Fern,) were investigated in laboratory and field studies. The burrs contain two types of seeds which differed in their innate dormancy. Primary seeds formed in the upper spikelet usually germinated within a year. Secondary seeds from lower spikelets germinated slowly and remained dormant for longer periods. Dormancy was enforced at low and high temperatures, and secondary seeds apparently developed an induced dormancy when continuously exposed to high temperatures. More than 94 % of the seedlings established during spring. Light suppressed germination, and secondary seeds also developed an induced dormancy when stored in the light. Burrs sown on the soil surface had an extended period of germination lasting for more than 3 years. However, over 96 % of the seeds sown below the surface of bare soil germinated within 2 years. Deep burial did not enforce dormancy, but germination was suppressed by the presence of live vegetation. It is concluded that treatments which disturb the soil and bury the burrs will stimulate the germination of dormant seeds.

Seeds and seedlings of the annual weed sand burr (Cenchrus longispinus) were introduced into undisturbed vegetation and fallowed soil in north-western Victoria. Survival and growth of the sand burr plants was significantly reduced on areas with a high density of skeleton weed (Chondrilla juncea), and on soils of heavy texture. The results suggest that sand burr will be confined to the margins of sand dunes and other places where the soil surface is sandy and relatively free of skeleton weed. Natural populations of sand burr produced sufficient dormant seeds in the stubble after cereal crops to enable the plant to persist through several years of ley pasture. Harbinger medic (Medicago littoralis) and lucerne (M. sativa) were sown under the cereal at two sites in 1971 to control sand burr seeding. Harbinger medic reduced sand burr density in the stubble at one site, but did not reduce seed production. Lucerne sown at 3.8 kg ha-1 or above reduced the number of dormant seeds formed in the stubble at the two sites. In the second year of pasture, the suppression of sand burr was independent of lucerne sowing rate.