THE EFFECT OF ETHEPHON ON ANNUAL BLUEGRASS AND CREEPING BENTGRASS GROWTH

1989 ◽  
Vol 69 (4) ◽  
pp. 1353-1357 ◽  
Author(s):  
J. L. EGGENS ◽  
C. P. M. WRIGHT ◽  
D. P. MURR ◽  
K. CAREY

Under pot culture and field conditions, ethephon at rates up to 8 kg ha−1 was more injurious to annual bluegrass than to Penncross creeping bentgrass. Ethephon significantly decreased the quality, spreading ability and shoot weight of annual bluegrass, whereas sward quality of the creeping bentgrass grown in pot culture was increased, spreading ability was unaffected and shoot dry weight decreased. Increasing the number of applications at all concentrations increased injury to annual bluegrass and a single application at 1 kg ha−1 reduced annual bluegrass seedhead production.Key words: Poa annua, Agrostis palustris, ethephon, sward quality

1989 ◽  
Vol 69 (1) ◽  
pp. 297-304
Author(s):  
C. P. M. WRIGHT ◽  
J. L. EGGENS ◽  
K. CAREY ◽  
R. J. HINES

The objective of this study was to determine if total plant leaf numbers in a large data set could be predicted from individual plant shoot dry weight measurements using regression equations derived from a subset of the data. The species used were annual bluegrass (Poa annua L.) and creeping bentgrass (Agrostis palustris Huds. ’Penncross’). There was significant correlation between leaf number and shoot dry weight measurements in data subsets. Leaf numbers for the total data set were estimated by the regression equation derived from a subset consisting of pooled data from one, two or three replicates. This procedure was assessed by comparing predictions from regression equations with actual values, using a number of different sets of replicates to generate the regression equation. On the basis of the results we suggest that, for annual bluegrass and creeping bentgrass in greenhouse pot culture, this procedure can be used to accurately estimate leaf number data for remaining replicates within an experimental design, once regression coefficients are established from pooled data from two replicates.Key words: Leaf number estimation, shoot dry weight, annual bluegrass, creeping bentgrass


HortScience ◽  
2001 ◽  
Vol 36 (2) ◽  
pp. 371-373 ◽  
Author(s):  
Xia Xu ◽  
Charles F. Mancino

Many biotypes of annual bluegrass (Poa annua L.) are found on golf course putting greens. Although normally considered an invasive weed, annual bluegrass can provide as good a putting surface as creeping bentgrass (Agrostis palustris Huds.). The most desirable biotypes of annual bluegrass are primarily vegetative and have a low flowering frequency. Whether the nutritional requirements of annual bluegrass biotypes differ from one another or from creeping bentgrass is unknown. The response of three flowering (FAB, high seedhead production) and three vegetative (VAB, low seedhead production) biotypes of annual bluegrass (AB), and the three parents of `Penncross' creeping bentgrass (CB) to varying levels of iron (Fe) in greenhouse sand culture was investigated. After establishment, clones were grown for 3 weeks and irrigated with a half-strength Hoagland's solution containing 0, 2, 4, 6, and 8 mg·L-1 Fe in citrate-Fe. Shoot and root responses to Fe were similar for the VAB and FAB biotypes. However, VAB had higher color ratings (darker green leaf color) with Fe treatment level at 4 mg·L-1 than did FAB or CB, which required 6 mg·L-1 Fe for acceptable color. Growth of creeping bentgrass was greater than that of annual bluegrass at every Fe level tested. Shoot dry weights of CB increased significantly with Fe treatment level up to 6 mg·L-1. Shoot dry weight of AB increased up to 4 mg·L-1 Fe and then declined at ≥6 mg·L-1. Root growth of CB increased up to 6 mg·L-1 Fe, but then decreased significantly at 8 mg·L-1 Fe. Root growth of AB increased slightly up to 4 mg·L-1 Fe and then declined at 6 and 8 mg·L-1. Shoot tissue concentrations of Fe were similar for AB and CB at each Fe rate tested except at 8 mg·L-1 Fe, where Fe levels in CB were significantly lower. Based on this work, creeping bentgrass and annual bluegrass respond differently to Fe nutrition, but different biotypes of annual bluegrass appear to respond similarly.


Author(s):  
Aline das Graças Souza ◽  
Oscar josé Smiderle

The Brazil nut (Bertholletia excelsa H.B.K.) is fast-growing, and can be used in reforestation. However, the use of the species in reforestation is still uncommon, mainly due to production costs, with substrate and fertiliser being the most-costly components. Based on the above, the aim of this study was to evaluate growth and quality in seedlings of the Brazil nut both with and without nutrient solution. The experimental design was completely randomised in a 2 x 10 factorial scheme: treatments with and without the addition of nutrient solution and 10 evaluations at intervals of 45 days. The variables to be analysed were height, stem diameter, dry shoot weight, root dry weight, total dry weight and the Dickson quality index. When analysing shoot dry weight (SDW), a gain of 85% was found from adding the nutrient solution, compared to the absence of nutrient solution, whereas for the variable, root-system dry weight, (RDW) the gain was 43%. The addition of nutrient solution is suggested for accelerating the growth and development of high-quality seedlings of Bertholletia excelsa for commercial use.


2006 ◽  
Vol 20 (4) ◽  
pp. 1015-1022 ◽  
Author(s):  
Darren W. Lycan ◽  
Stephen E. Hart

Response of creeping bentgrass, annual bluegrass, and Kentucky bluegrass to foliar, soil, or foliar plus soil applications of bispyribac-sodium was evaluated in greenhouse studies. Soil-alone and foliar plus soil applications of bispyribac-sodium at 148 or 296 g ai/ha resulted in greater injury and shoot dry weight reduction of all species 28 d after treatment (DAT) compared to foliar-alone treatments. Creeping bentgrass was less injured than annual or Kentucky bluegrass regardless of application placement. Further studies evaluated foliar and root absorption and translocation of14C-bispyribac-sodium in creeping bentgrass, annual bluegrass, Kentucky bluegrass, and roughtstalk bluegrass. Foliar absorption into creeping bentgrass was less than that of other species at most harvest timings from 4 to 72 h after treatment. Annual and roughstalk bluegrass translocated greater amounts of foliar-absorbed14C to the crown and shoots compared to creeping bentgrass. Annual and roughstalk bluegrass accumulated approximately 47% more14C per dry weight of plant tissue than creeping bentgrass and 74% more than Kentucky bluegrass after 72 h in nutrient solution containing14C-bispyribac-sodium. Annual and roughstalk bluegrass translocated approximately 80% of root-absorbed14C to shoots, whereas creeping bentgrass and Kentucky bluegrass translocated slightly less (66% of absorbed for both species). These studies suggest that bispyribac-sodium is readily absorbed by roots and translocated to shoots which may contribute to its total activity within a plant. In addition, creeping bentgrass displayed lower amounts of foliar and root absorption and subsequent translocation than annual and roughstalk bluegrass which may contribute to greater bispyribac-sodium tolerance displayed by creeping bentgrass.


HortScience ◽  
2001 ◽  
Vol 36 (4) ◽  
pp. 784-786 ◽  
Author(s):  
Xia Xu ◽  
Charles F. Mancino

Annual bluegrass (Poa annua L.) is becoming an important component of golf course putting greens. A greenhouse sand culture experiment was conducted to study the zinc (Zn) requirements of three genotypes of flowering annual bluegrass (FAB) and three genotypes of vegetative annual bluegrass (VAB), which were compared with the three parents of `Penncross' creeping bentgrass [Agrostis stolonifera L. (CB)]. Clonally propagated plants were grown in sand culture without Zn for 6 weeks prior to the initiation of the Zn treatments. The plants were then irrigated for 3 weeks with half-strength Hoagland's nutrient solution containing 0, 2.5, 5.0, or 40 mg·L-1 Zn from ZnSO4. Color was the only parameter affected by genotype; each genotype showed a significant quadratic response to increasing levels of Zn, with highest color ratings occurring at 2.5 mg·L-1. No genotypic differences were observed among CB, VAB, and FAB for shoot fresh and dry weight, root dry weight, or shoot tissue Zn concentrations. Shoot dry weight of all genotypes increased quadratically with Zn levels. Root dry weights of both VAB and FAB increased, while that of CB remained unchanged, as Zn level increased. Zinc concentrations in shoot tissue increased linearly as Zn level increased. Shoot Zn concentrations were higher in both VAB and FAB than in CB at each Zn level, but differences between VAB and FAB were insignificant. Maintaining shoot Zn concentrations below 109 mg·kg-1 in CB and 200 mg·kg-1 in VAB or FAB prevented Zn phytotoxicity from occurring.


2017 ◽  
Vol 27 (4) ◽  
pp. 472-481 ◽  
Author(s):  
Nicholas J. Flax ◽  
Christopher J. Currey ◽  
James A. Schrader ◽  
David Grewell ◽  
William R. Graves

Our objectives were to quantify the growth and quality of herbaceous annuals grown in different types of bioplastic-based biocontainers in commercial greenhouses and quantify producer interest in using these types of biocontainers in their production systems. Seedlings of ‘Serena White’ angelonia (Angelonia angustifolia) and ‘Maverick Red’ zonal geranium (Pelargonium ×hortorum) that had been transplanted into nine different (4.5-inch diameter) container types [eight bioplastic-based biocontainers and a petroleum-based plastic (PP) (control)] were grown at six commercial greenhouses in the upper midwestern United States. Plants were grown alongside other bedding annuals in each commercial greenhouse, and producers employed their standard crop culture practices. Data were collected to characterize growth when most plants were flowering. Questionnaires to quantify producer perceptions and interest in using bioplastic-based biocontainers, interest in different container attributes, and satisfaction were administered at select times during the experiment. Container type interacted with greenhouse to affect angelonia growth index (GI) and shoot dry weight (SDW), as well as shoot, root, and container ratings. Container type or greenhouse affected geranium GI and shoot rating, and their interaction affected SDW, and root and container ratings. These results indicate that commercial producers can grow herbaceous annuals in a range of bioplastic-based biocontainers with few or no changes to their crop culture practices.


Plant Disease ◽  
1999 ◽  
Vol 83 (6) ◽  
pp. 516-520 ◽  
Author(s):  
Yan Feng ◽  
Peter H. Dernoeden

Putting green samples (n = 109) were inspected for the presence of Pythium oospores in roots of plants from golf courses (n = 39) in Maryland and adjacent states. Twenty-eight Pythium isolates were recovered from creeping bentgrass (Agrostis palustris) (n = 25) and annual bluegrass (Poa annua) (n = 3) plants. Most isolates associated with Pythium-induced root dysfunction were from greens less than 3 years of age and were obtained primarily between March and June, 1995 to 1997. Eight Pythium species (P. aristosporum, P. aphanidermatum, P. catenulatum, P. graminicola, P. torulosum, P. vanterpoolii, P. volutum, and P. ultimum var. ultimum) were isolated from creeping bentgrass and two species (P. graminicola and P. torulosum) were from annual bluegrass. All species, except P. catenulatum, were pathogenic to ‘Crenshaw’ creeping bentgrass seedlings in postemergence pathogenicity tests. P. aristosporum (n = 3) and P. aphanidermatum (n = 1) were highly aggressive at a low (18°C) and a high temperature (28°C). P. graminicola (n = 1) was low to moderately aggressive. P. torulosum (n = 12) was the most frequently isolated species, but most isolates were either nonpathogenic or caused very little disease. P. aristosporum (n = 3) and P. aphanidermatum (n = 1) were highly aggressive and were associated with rapid growth at 18 and 28°C on cornmeal agar. P. volutum (n = 1) was highly aggressive at 18°C, but was one of slowest growing isolates. Infected roots were generally symptomless, and the number of oospores observed in roots was not always a good indicator of disease or of the aggressiveness of an isolate. Large numbers of oospores of low or even nonpathogenic species may cause dysfunction of creeping bentgrass roots.


1991 ◽  
Vol 71 (2) ◽  
pp. 595-599 ◽  
Author(s):  
D. J. Cattani ◽  
M. H. Entz ◽  
K. C. Bamford

Tiller production and dry matter accumulation were monitored in six creeping bentgrass (Agrostis palustris Hud.) genotypes maintained as a putting green. Core samples for tiller density and aboveground biomass determinations were collected at intervals between October 1987 and October 1989. Two experimental lines, UM84-01 and UM86-01, produced more (P < 0.05) tillers and higher (P < 0.05) aboveground biomass than the commercial cultivars Penneagle, National, Emerald and Seaside. Both tiller density and aboveground biomass rankings among genotypes were consistent over the study period. Although lower tillering genotypes had a significantly higher aboveground biomass per tiller, total aboveground biomass was influenced more by tiller density than by biomass per tiller. The relationship between tiller density and tiller dry weight was expressed mathematically to determine potential wear stress resistance among genotypes. Key words: Creeping bentgrass, tillering, biomass accumulation


1992 ◽  
Vol 70 (11) ◽  
pp. 2193-2197 ◽  
Author(s):  
Clinton F. Hodges

Studies were initiated to determine the pathogenicity of Pythium torulosum to Agrostis palustris roots growing in sand with subsurface black layer produced by the interaction of cyanobacteria and the sulfate-reducing bacterium Desulfovibrio desulfuricans. The interaction of P. torulosum with cyanobacteria and D. desulfuricans was also evaluated. Pythium torulosum decreased the dry weight of roots and shoots of A. palustris to 41 and 35%, respectively, of the control plants in the absence of black layer and the organisms responsible for its formation. The combination of P. torulosum and D. desulfuricans, in the absence of black layer, induced the most severe decrease in root (20% of controls) and shoot (25% of controls) dry weights. Damage to roots induced by P. torulosum in combination with various isolates of cyanobacteria, in the absence of black layer, was equal to that of P. torulosum alone; shoot dry weight loss was less than that caused by P. torulosum alone. Pathogenicity of P. torulosum to roots when combined with cyanobacteria and D. desulfuricans in the presence of black layer was the same as that with P. torulosum alone and in combination with cyanobacteria; shoot dry weight did not differ from that of P. torulosum combined with cyanobacteria. The presence of cyanobacteria with P. torulosum and D. desulfuricans in black-layered sand decreased root and shoot dry weight loss induced by the two latter organisms. Key words: anaerobic, black plug layer, golf greens, sulfate reduction.


1994 ◽  
Vol 12 (3) ◽  
pp. 167-169
Author(s):  
G.J. Keever ◽  
C.H. Gilliam ◽  
D.J. Eakes

Abstract Ilex x meserveae ‘China Girl’ plants were sprayed with a single application of different rates of Cutless (flurprimidol) during container production. Growth index, shoot length and shoot dry weight decreased with increasing rates of Cutless. Growth index of plants treated with 500 ppm Cutless was about 17% less than that of control plants 120 days after treatment, but were similar after the spring flush the following year. Growth inhibition persisted for at least two growing seasons when plants were treated with rates of 1500 to 2500 ppm; foliage of these plants was smaller and more cupped than that of control plants. Treated plants were noticeably more compact and uniform, and foliage was darker green than that of control plants.


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