scholarly journals Effect of Shade on the Growth of Four Turfgrasses

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 649d-649
Author(s):  
Guofan Liu ◽  
Kent D. Kobayashi

Four turfgrasses (Z-3, Seashore Paspalum, Common Bermuda, and Tif dwarf Bermuda) were grown outdoors in pots under different shade conditions (0%, 30%, and 50% shade) from August to December 1995. Dry weight of clippings taken every two weeks was determined. Turfgrass growth in the three shade treatments were significantly different, and the growth of the turfgrasses were highly significantly different. In the 0% and 30% shade treatments, Common Bermuda and Seashore Paspalum grew similarly, and their dry weights were significantly greater than those of Z-3 and Tif dwarf Bermuda. However, under 50% shade, only Seashore Paspalum grew significantly greater than the others. Comparing growth among the shade treatments for each turfgrass, we found no significantly differences. Only Common Bermuda grew significantly less under 50% shade than under 0% and 30% shade. Common Bermuda is good for golf courses because of its fast growth and attractiveness. Seashore Paspalum can be used for home lawns because of its vigorous growth and shade tolerance. Z-3 turfgrass, an attractive new variety for home lawns, despite its slow growth, is tolerant of different shade conditions.

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 444C-444
Author(s):  
Guofan Liu ◽  
Kent D. Kobayashi

Turfgrass is grown under a wide range of environmental conditions, especially light conditions. In residential and commercial applications, selecting the appropriate turfgrass depends, in part, upon its performance under differing light conditions. This study was conducted to determine the growth habits of four turfgrasses under different shade treatments. `Common Bermuda', `Tif dwarf Bermuda', `Seashore Paspalum', and `Z-3' were grown outdoors in pots. `Z-3' is an attractive new variety of turfgrass for residential lawns. Benches were covered with shade cloth to provide different shade conditions (0%, 30%, and 50% shading). Clippings were taken every 2 weeks and dried to determine growth. Turfgrass growth under the three shade treatments were significantly different. In the 0% and 30% shade treatments, `Common Bermuda' and `Seashore Paspalum' had similar growth with their dry weights being greater than that of `Tif dwarf Bermuda' and `Z-3'. Under 50% shade, `Seashore Paspalum' grew significantly greater than the other turfgrasses. `Common Bermuda' grew significantly less under 50% shade than under 0% and 30% shade. `Common Bermuda' does well on golf courses because of its fast growth and attractiveness. With its vigorous growth and shade tolerance, `Seashore Paspalum' can be used for residential lawns. `Z-3' turfgrass, a relatively new variety for residential lawns, shows slow growth but is desirable because of its tolerance to different shade conditions.


Plant Disease ◽  
2004 ◽  
Vol 88 (6) ◽  
pp. 680-680 ◽  
Author(s):  
A. C. Hixson ◽  
W. T. Crow

Seashore paspalum (Paspalum vaginatum Swartz) is a warm-season grass capable of growing in the saline environments present in coastal areas of Florida (2). A major limitation of cultivating turfgrasses in the sandy soils of Florida is the destruction of roots by plant-parasitic nematodes (3). A survey was performed to determine the plant-parasitic nematodes associated with seashore paspalum. Sampling locations ranged from Daytona Beach to Miami Beach on the eastern coast and from Tampa to Naples on the western coast. Soil samples were taken during the spring and summer months of 2002 and 2003 from different golf courses and home lawns. In 2002, soil samples were taken from five golf courses (37 samples) and seven home lawns (17 samples). In the next year, three golf courses (23 samples) and 13 home lawns (34 samples) were sampled. Nematodes were extracted from 100 cm3 soil samples using a modified centrifugal-sugar flotation technique (1). Ten genera of plant-parasitic nematodes were present from the samples obtained from golf courses. In addition, two more plant-parasitic nematode genera were present in samples from home lawns. The genera most frequently detected were Hoplolaimus, Mesocriconema, Hemicriconemoides, and Helicotylenchus, which were found at 100, 100, 88, and 88% of the golf courses surveyed and at 75, 95, 70, and 85% of the home lawns sampled, respectively. Genera Xiphinema, Pratylenchus, and Tylenchorhynchus, were found in less than 30% of the golf courses and less than 45% of the home lawns sampled. Genera Peltamigratus and Hemicycliophora were associated with a low percentage of the home lawns. A moderately high frequency of the genus Belonolaimus present in soil samples from golf courses (50%) and home lawns (40%) was consistent for other grasses grown in sandy soils associated with coastal areas in Florida (4). Populations of the genera Belonolaimus, Hoplolaimus, Helicotylenchus, Trichodorus, Hemicriconemoides, and Mesocriconema were above the action threshold levels for bermudagrass used by the University of Florida Nematode Assay Laboratory. Genera Hoplolaimus, Belonolaimus, and Trichodorus were associated with irregular-shaped yellowing and declining turfgrass areas sampled in this survey. Large populations of Helicotylenchus spp. (>500 nematodes per 100 cm3 of soil) were often found associated with seashore paspalum. To our knowledge, this is the first report of plant-parasitic nematodes associated with seashore paspalum in Florida. References: (1) W. R. Jenkins. Plant Dis. Rep. 48:692, 1964. (2) J. Morton. Proc. Fla. State Hortic. Soc. 86:482, 1973. (3) V. G. Perry and H. Rhoades. Pages 144–149 in: Nematology in the Southern Region of the United States. Southern Cooperative Series Bull. 276, University of Arkansas Agric. Pub., Fayetteville, 1982. (4) R. T. Robbins and K. R. Barker. J. Nematol. 6:1, 1974.


2003 ◽  
Vol 13 (1) ◽  
pp. 74-76 ◽  
Author(s):  
J.W. Boyd ◽  
M.D. Richardson ◽  
J.H. McCalla

Zoysiagass (Zoysia japonica) use continues to expand on golf courses, home lawns, and sports fields in the transition zone. Unfortunately, the slow growth rate of the species and long establishment period have limited its use to those sites that can afford zoysiagrass sod. The development of sprig-planting techniques that can produce a zoysiagrass turf in a single season would considerably increase the use of this desirable species. A study was conducted over 2 years at two different regions in Arkansas to evaluate the efficacy of a new zoysiagrass net-planting technique (ZNET) on establishment of zoysiagrass from vegetative sprigs. The technique involves rolling the sprigs onto the site in cotton netting and top-dressing the sprigs with 1.0 cm (0.4 inch) of native soil. This technique was compared to a standard sprig-planting technique and a standard sprig planting that was also top-dressed with 1.0 cm of native soil. The standard treatments were planted according to established methods using freshly-harvested sprigs applied at a rate of 70.0 m3·ha-1 [800 bushels (1000 ft3) per acre]. Rate of turfgrass cover was monitored throughout the growing season. The ZNET planting technique significantly improved establishment over the traditional sprigging technique and the turf reached about 85% cover by the end of the growing season (120 days). Top-dressing a traditionally sprigged area with native soil also improvedestablishment compared to traditional sprigging and was comparable to the ZNET technique. It was concluded that the ZNET technique did improve establishment rates of zoysiagrass, but the same results could be attained by top-dressing sprigs that were planted with a standard planter.


HortScience ◽  
2014 ◽  
Vol 49 (11) ◽  
pp. 1444-1448 ◽  
Author(s):  
Kenton W. Peterson ◽  
Jack D. Fry ◽  
Dale J. Bremer

‘Meyer’ zoysiagrass (Zoysia japonica Steudel) is commonly planted on home lawns and golf courses in the transition zone; however, poor shade tolerance limits its widespread use. This study was conducted to determine changes and differences in growth among selected Zoysia cultivars and progeny under a natural shade environment over a 3-year period in the transition zone. The study was initiated in June 2010 at the Rocky Ford Turfgrass Research Center in Manhattan, KS. Soil type was a Chase silt loam (fine, montmorillonitic, mesic, Aquic, Argiudoll). Zoysia genotypes were sodded in 0.37-m2 plots and arranged in a randomized complete block with five replications under silver maple (Acer saccharinum L.) shade that resulted in a 91% reduction in photosynthetically active radiation (PAR). Genotypes included ‘Zorro’ [Z. matrella (L.) Merrill], ‘Emerald’ [Z. japonica × Z. pacifica (Goudswaard) Hotta & Kuroki], ‘Meyer’, Chinese Common (Z. japonica), and experimental progeny Exp1 (Z. matrella × Z. japonica), and Exp2 and Exp3 [(Z. japonica × Z. pacifica) × Z. japonica]. ‘Zorro’ and ‘Emerald’ experienced winter injury, which negatively affected their performance. Tiller numbers decreased 47% in ‘Meyer’ from June 2010 to June 2012, but declines in [(Z. japonica × Z. pacifica) × Z. japonica] progeny were only 1% for Exp2 and 27% for Exp3, and both Exp2 and Exp3 maintained high percent green cover throughout the study. In general, by the third year of evaluation, progeny of [(Z. japonica × Z. pacifica) × Z. japonica] had higher quality ratings and higher tiller numbers than ‘Meyer’ and may provide more shade-tolerant cultivar choices for transition zone turf managers.


2001 ◽  
Vol 31 (11) ◽  
pp. 2049-2057 ◽  
Author(s):  
Tongli Wang ◽  
Sally N Aitken

Variation in xylem anatomy among selected populations of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) was examined using digital image analysis based on an annual growth ring (age 10) per tree. Four subpopulations were selected using the following criteria for height growth and wood density: (i) fast growth and high density; (ii) slow growth and high density; (iii) fast growth and low density; and (iv) slow growth and low density. Significant differences were found among subpopulations for several anatomical parameters including tracheid density, lumen size, and cell wall thickness that may affect the economic value and utilization of wood. Principal component analysis indicate that the first four principal components (PCs) were associated with (i) ring area (PC1), (ii) earlywood density (PC2), (iii) latewood density (PC3), and (iv) lumen shape in earlywood (PC4), suggesting that these aspects of wood properties and growth are controlled by different sets of genes. Relative contributions of total number of tracheids, tracheid lumen size, and cell wall thickness to ring area and correlations between cell wall area proportion and X-ray density are discussed.


1979 ◽  
Vol 36 (12) ◽  
pp. 1497-1502 ◽  
Author(s):  
L. J. Buckley

The protein, DNA, and RNA content of larvae maintained at 1.0 plankter/mL increased at the rates of 9.3, 9.9, and 9.8% per day, respectively, for the 5 wk after hatching. Protein reserves of larvae held at 0 or 0.2 plankters/mL were depleted by 45 and 35%, respectively, prior to death 12–13 d after hatching. Starved larvae had similar protein concentrations (percent of dry weight), lower RNA concentrations, and higher DNA concentrations than fed larvae. Larvae held at higher plankton densities had higher RNA–DNA ratios and faster growth rates than larvae held at lower plankton densities. The RNA–DNA ratio was significantly correlated (P < 0.01) with the protein growth rate. The RNA–DNA ratio appears to be a useful index of nutritional status in larval Atlantic cod (Gadus morhua) and may be useful for determining if cod larvae were in a period of rapid or slow growth at the time of capture. Key words: RNA–DNA ratio, starvation, protein, nucleic acids, growth, larval fish, Atlantic cod


INDIAN DRUGS ◽  
2018 ◽  
Vol 55 (07) ◽  
pp. 20-27
Author(s):  
Tamrat Balcha ◽  
◽  
Nisha Mary Joseph ◽  
Anteneh Belete

Taro Boloso-I is a new variety of Colocasia esculenta (L. Schott) officially released from Areka Agricultural Research Center, Areka, Ethiopia. Its cultivation out yields a previously reported variety (Godare) by 67%. The study focuses on isolation and characterization of starch from this plant. Isolation of starch was done using saline and sodium hydroxide and characterized for its physicochemical constituents. Its yield on dry weight basis was 83.5 ± 1.6%. The native Taro Boloso-I starch (NTBIS) showed lower amylose to amylopectin ratio (20.7 ± 1.8% to 77.3 ± 2.1%, w/w) and significantly higher onset (68.40˚C), peak (75.46 ˚C) and endset (84.40 ˚C) temperatures of gelatinization than potato starch which has gelatinization range of 62.50–67.53–79.40 ˚C. The shapes of the granules were polyhedral/angular with an A-type polymorphism with a poor flow.The starch is comprised of small particles (mean diameter of 2.45 ± 0.11 μm).Taro Boloso-I starch possesses similarity with cereal starches like the rice starch though it is a tuber starch and moreover, on comparison with the previously reported varieties of Taro, there is difference in its properties.


Microbiome ◽  
2020 ◽  
Vol 8 (1) ◽  
Author(s):  
M. Carla Piazzon ◽  
Fernando Naya-Català ◽  
Erick Perera ◽  
Oswaldo Palenzuela ◽  
Ariadna Sitjà-Bobadilla ◽  
...  

Abstract Background The key effects of intestinal microbiota in animal health have led to an increasing interest in manipulating these bacterial populations to improve animal welfare. The aquaculture sector is no exception and in the last years, many studies have described these populations in different fish species. However, this is not an easy task, as intestinal microbiota is composed of very dynamic populations that are influenced by different factors, such as diet, environment, host age, and genetics. In the current study, we aimed to determine whether the genetic background of gilthead sea bream (Sparus aurata) influences the intestinal microbial composition, how these bacterial populations are modulated by dietary changes, and the effect of selection by growth on intestinal disease resistance. To that aim, three different groups of five families of gilthead sea bream that were selected during two generations for fast, intermediate, or slow growth (F3 generation) were kept together in the same open-flow tanks and fed a control or a well-balanced plant-based diet during 9 months. Six animals per family and dietary treatment were sacrificed and the adherent bacteria from the anterior intestinal portion were sequenced. In parallel, fish of the fast- and slow-growth groups were infected with the intestinal parasite Enteromyxum leei and the disease signs, prevalence, intensity, and parasite abundance were evaluated. Results No differences were detected in alpha diversity indexes among families, and the core bacterial architecture was the prototypical composition of gilthead sea bream intestinal microbiota, indicating no dysbiosis in any of the groups. The plant-based diet significantly changed the microbiota in the intermediate- and slow-growth families, with a much lower effect on the fast-growth group. Interestingly, the smaller changes detected in the fast-growth families potentially accounted for more changes at the metabolic level when compared with the other families. Upon parasitic infection, the fast-growth group showed significantly lower disease signs and parasite intensity and abundance than the slow-growth animals. Conclusions These results show a clear genome-metagenome interaction indicating that the fast-growth families harbor a microbiota that is more flexible upon dietary changes. These animals also showed a better ability to cope with intestinal infections.


Weed Science ◽  
1993 ◽  
Vol 41 (4) ◽  
pp. 541-547 ◽  
Author(s):  
Emilie E. Regnier ◽  
S. Kent Harrison

Lower leaves of greenhouse-grown common cocklebur and velvetleaf were shaded to 5% of full light over a 12-d period while upper leaves remained exposed to full light to determine weed foliar and branching responses to partial shading similar to that encountered in soybean crops. Shading increased lower leaf senescence and specific leaf area, and decreased branch length and number of second-order leaves in both species compared to unshaded controls. Common cocklebur branched more extensively along the lower portion of its stem than velvetleaf under both shaded and unshaded conditions. Upper leaves of partially shaded velvetleaf were held in a more perpendicular position to the light source beginning 3 days after treatment (DAT) compared to upper leaves of unshaded plants. Shading of lower leaves caused an increase in upper (unshaded) leaf area beginning 3 and 6 DAT in velvetleaf and common cocklebur, respectively. Petiole length of upper leaves also increased in response to shading in both species. Total plant dry weight at 12 DAT was unaffected by shading in velvetleaf but was reduced 10% by shading in common cocklebur. While common cocklebur maintained greater lower shoot growth in the presence of shade than velvetleaf, there was a greater change in upper leaf angle by velvetleaf in response to shading than by common cocklebur. These results support previous field observations of apparent greater shade tolerance of common cocklebur compared to velvetleaf and indicate that both species have the ability to compensate for shading of lower leaves by altering upper shoot growth.


2009 ◽  
Vol 49 (6) ◽  
pp. 504 ◽  
Author(s):  
B. L. McIntyre ◽  
G. D. Tudor ◽  
D. Read ◽  
W. Smart ◽  
T. J. Della Bosca ◽  
...  

Growth, carcass characteristics and meat quality of the steer and heifer progeny of autumn (AC: March–April) and winter (WC: June–July) calving cows following weaning in January in each of 3 years (2003–05) were measured. The cows were mated to sires with a high estimated breeding value for either retail beef yield (RBY), intramuscular fat (IMF) or both RBY and IMF. After weaning, the progeny entered one of three growth paths until slaughter at an average steer liveweight of 500 kg: (i) fast – fast growth from weaning on a high concentrate feedlot diet; (ii) slow – slow growth from weaning (~0.6 kg/day) to 400 kg liveweight followed by growth at over 1 kg/day on high quality pasture; or (iii) comp. – 10% weaning weight loss, immediately after weaning followed by compensatory or rapid growth of over 1 kg/day on high quality pasture. Steers on the fast growth path had higher (P < 0.001) P8 fat thickness than those on the slow or comp. growth paths whereas heifers on the fast growth path only had higher (P < 0.001) P8 fat thickness than those on the slow growth path. Animals on the fast growth treatment had higher (P < 0.001) levels of IMF% than the slow animals which were higher (P < 0.001) than the comp. growth treatment. AUS-MEAT and US marbling scores were not different among growth paths. Animals finished on the fast growth path had a lower (P < 0.001) RBY% than those on either the slow or comp. growth paths. The RBY-sired progeny had higher (P < 0.001) finishing liveweight and hot standard carcass weight than either RBY and IMF or IMF-sired animals. IMF-sired progeny had higher (P < 0.01) rib fat thickness than either RBY or RBY- and IMF-sired animals. There was also a similar trend for P8 fat thickness but the effects were not significant. The RBY-sired animals had lower AUS-MEAT marbling scores (P < 0.01), US marbling scores (P < 0.001) and levels of IMF% (P < 0.01) than either of the other two sire treatments. RBY-sired animals also had higher (P < 0.001) estimated RBY% than those from the IMF sires while those by RBY and IMF sires were intermediate and not significantly different from either. Calving time had little influence on most carcass characteristics. However, WC animals tended to be fatter and have higher marbling scores than AC animals. The IMF% was higher (P < 0.01) in WC animals from RBY and IMF sires than in the corresponding AC animals. Heifers had lighter slaughter liveweight, carcass weight, were fatter and had higher marbling scores than steers. Heifers also had lower (P < 0.001) RBY% than the steers. Ossification scores for heifers were higher (P < 0.001) than for steers by ~30 units in AC calves and by 20 units in WC calves. The results of this experiment confirm the effectiveness of using sires with high estimated breeding value for the required characteristics in producing the desired improvements in the progeny. The absence of any interactions of sire type with growth path indicates that differences between sire types will be similar regardless of environmental conditions. Animals raised on a faster growth path after weaning produce carcasses with more fat and more IMF% than those grown on slower growth paths.


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