Response of some tropical grasses to molybdenum application

1978 ◽  
Vol 18 (94) ◽  
pp. 732 ◽  
Author(s):  
C Johansen

The response to Mo application of Panicum maximum var. trichoglume cv. Gatton (panic), Cenchrus ciliaris cv. Biloela (buffel) and Setaria sphacelata cv. Nandi (setaria) was studied at three rates of NO3 supply in pots containing soil that was severely Mo deficient for tropical legumes. There were no growth responses of these grasses to Mo, except for a marginally significant effect in panic at the highest NO3 treatment at the first harvest. These results are compared with Mo responses of legume/grass mixtures in the field and published data showing large growth responses of some temperate grasses to Mo. Application of Mo had no effect on total N concentrations of grass tops but markedly decreased NO3-N concentrations in buffel. Setaria had a greater ability to take up Mo than the other grasses and this was associated with the lower NO3 levels in this species. Critical Mo concentrations for growth of all grasses were below 0.02 p.p.m.

Ecotoxicology ◽  
2019 ◽  
Vol 28 (8) ◽  
pp. 853-868 ◽  
Author(s):  
Tsetan Dolker ◽  
Arideep Mukherjee ◽  
Shashi Bhushan Agrawal ◽  
Madhoolika Agrawal

1973 ◽  
Vol 21 (1) ◽  
pp. 3-11
Author(s):  
J.G. Boonman

Setaria sphacelata cv. Nandi I and Nandi III, Chloris gayana cv. Mbarara, Masaba and Pokot, and Panicum coloratum cv. Solai were grown for seed and harvested on a range of dates beginning 3-4 weeks after initial head emergence (defined as 5-10 heads/m2). Harvesting date was not very critical, and harvesting could normally be spread over 1-2 weeks. The interval between initial heading and optimum harvest date was normally 6-7 weeks. In most crops considerable shedding of spikelets (up to 30-50% in P. coloratum, rather less in the other 2 species) could be tolerated before yield of pure germinating seed fell with delay in harvesting. It was suggested that most of the spikelets which were shed early were empty. Cultivars which headed early produced nearly twice as much seed as those which headed late. (Abstract retrieved from CAB Abstracts by CABI’s permission)


1975 ◽  
Vol 15 (74) ◽  
pp. 383 ◽  
Author(s):  
FW Smith

The possibility of using phosphorus concentrations in different parts of pasture grasses for diagnosing their phosphorus status was studied. Critical phosphorus concentrations using youngest expanded leaves of green panic (Panicum maximum var. trichoglume cv. Petrie), buffel grass (Cenchrus ciliaris cv. Biloela), or setaria (Setaria sphacelata cv. Nandi) were found to be almost identical to those assessed from the whole tops. Critical phosphorus concentrations in green panic and setaria decreased with age of plant, and for whole tops of green panic were : 0.55 per cent in plants with three to four leaves on the primary shoot, 0.32 per cent in plants with four to five leaves on the primary shoot and 0.1 5 per cent in plants with six to seven leaves on the primary shoot. Values in the whole tops of setaria were: 0.46 per cent (four leaves), 0.36 per cent (five leaves), 0.24 per cent (six leaves) and 0.14 per cent (seven leaves). A similar decline with stage of growth was observed when youngest expanded leaves were used to estimate critical phosohorus concentrations in setaria


1993 ◽  
Vol 33 (3) ◽  
pp. 337 ◽  
Author(s):  
RD Armstrong ◽  
KR Helyar

The influence of phosphorus (P) applied to mulga topsoil on the growth of Aristida amata, Cenclirus ciliaris, Digitaria ammophila, and Thyridolepis mitchelliana was examined in2 glasshouse trials, to test the hypothesis that the invasion of A. amata into mulga shrublands may result from a superior ability to exploit and utilise soil P compared to the other grasses.Growth of all grasses was poor without added P, and all grasses produced large growth responses to added P. In contrast to the other native grasses, A. armata required as much added P as the exotic C. ciliaris to achieve maximum growth. The ability of the grasses to grow without added P was related more to an ability to absorb P than to differences in internal requirements. With no P added, T. mitchelliana had the highest P absorption rate (�g P/g root.day), followed by A. amata, C. ciliaris, and D. ammophila. Adding P reversed this order. Cenchrus ciliaris and D. ammophila had the highest relative growth rates of shoots during early growth stages, especially with P added. Although A amata had a greater ability than C. ciliaris to access and utilise soil P at low P concentrations, there was no evidence that it was superior to the other native grasses.


2020 ◽  
Vol 54 (2) ◽  
pp. 299-311
Author(s):  
A. G. Desnitskiy

More than ten new species of colonial volvocine algae were described in world literature during recent years. In present review, the published data on taxonomy, geographical distribution and the species problem in this group of algae, mainly from the genera Gonium, Pandorina, Eudorina, and Volvox, are critically discussed. There are both cosmopolitan volvocalean species and species with local or disjunct distribution. On the other hand, the description of new cryptic taxa in some genera of the colonial family Volvocaceae, such as Pandorina and Volvox, complicates the preparation of a comprehensive review on their geography.


1973 ◽  
Vol 8 (1) ◽  
pp. 110-121
Author(s):  
A. Netzer ◽  
J.D. Norman

Abstract The merits of activated carbon for removal of organic compounds from wastewater have been well documented in the literature. On the other hand there is a lack of published data on the use of activated carbon for the removal of trace metals from wastewater. Experiments were designed to assess the possibility that activated carbon treatment would remove aluminum, cadmium, chromium, cobalt, copper, iron, lead, manganese, mercury, nickel, silver and zinc from wastewater. All metals studied were tested over the pH range 3-11. Greater than 99.5% removal was achieved by pH adjustment and activated carbon treatment for most of the metals tested.


Author(s):  
D J Worthington ◽  
E M Hammond ◽  
B B Eldeeb ◽  
A Green ◽  
G M Addison ◽  
...  

The overproduction of catecholamines and their metabolites is a well recognised feature of neuroblastoma. Published data are scarce for their urinary excretion in children with neuroblastoma and in ill children in whom this diagnosis may be considered. We have determined a graphical upper reference limit for total catecholamines, total metadrenalines and HMMA in urine, expressed as a ratio to the creatinine concentration, for a group of 174 children with neuroblastoma and 704 hospitalised children with other disorders. This graph has been determined by examining the overlap region between the results for the two groups of children and avoids the irregularities caused by statistical outliers. The sensitivity and specificity of the individual tests indicate that total catecholamines is marginally the best single test to perform when trying to diagnose neuroblastoma, with the best clinical sensitivity being achieved by examining both total catecholamines and HMMA. Only two of the 174 children with neuroblastoma would not have been detected using these two tests. Total metadrenalines did not appear to add any further information and could be dropped from the repertoire in favour of the other two measurements.


2016 ◽  
Vol 38 (3) ◽  
pp. 363 ◽  
Author(s):  
Frank Akiyoshi Kuwahara ◽  
Gustavo Maia Souza ◽  
Kezia Aparecida Guidorizi ◽  
Ciniro Costa ◽  
Paulo Roberto de Lima Meirelles

Water deficiency during the dry seasons influences the relationship between water and gas exchange in tropical grasses, reducing their productive potential. In addition, the phosphorus (P) deficiency Brazilian soils adds to the set of factors limiting crop production. In this context, the objective of this study was to evaluate the responses of different tropical forage species to phosphorus supplementation as mitigating the damage caused by water stress. Seeds of Urochloa brizantha cv. MG-4, Urochloa decumbens cv. Basilisk, Panicum maximum cv. Áries, Panicum maximum cv. Tanzânia and Paspalum atratum cv. Pojuca were germinated in pots containing 10 liters of red-yellow Acrisol type soil. Experiments were conducted by combining levels of phosphorus, 8,0 and 100,0 mg of P dm-3, with two irrigation regimes, 100 and 40% replacement of transpired water. The biometric parameters, photosynthetic capacity, leaf water potential and soil chemical characteristics were evaluated, and the data was submitted to analysis of variance (ANOVA, p < 0.05), and subsequently the means were compared using a Tukey test (p < 0.05). The results showed for tropical grasses grown under water stress, there is a clear mitigating effect of phosphorus supplementation, especially on the maintenance of biomass growth. 


2019 ◽  
Author(s):  
Madison Leigh Pesowski ◽  
Ori Friedman

From ancient objects in museums to souvenirs obtained on vacation, we often value objects for their distinctive histories. The present experiments investigate the developmental origins of people’s feelings that objects with distinctive histories are special. In each of four experiments, 4- to 7-year-olds (total N = 400) saw pairs of identical-looking objects in which one object was new and the other had a history that was either distinctive or mundane. In the first experiment, the histories did not involve people; in the remaining experiments, the histories were personal and related the objects to particular people. Distinctive histories affected children’s valuations of regular objects (all experiments), but not their valuations of stuffed animals. Both older and younger children viewed regular objects with distinctive histories as more special than those with mundane histories. Older children mostly viewed objects with distinctive histories as more special than new objects, and younger children showed similar judgments when judging which object a person cared about more. Together, the findings reveal a novel way that information about the past influences children’s judgments about the present and suggest that young children’s valuations of objects depend on objects’ histories.


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