SELENIUM ENRICHMENT OF CROPS THROUGH FOLIAR APPLICATIONS

1988 ◽  
Vol 68 (3) ◽  
pp. 519-526 ◽  
Author(s):  
UMESH C. GUPTA ◽  
K. A. WINTER ◽  
K. B. McRAE

A field study was conducted, at two locations on Prince Edward Island, over a 5-yr period to determine the effects of foliar applications of sodium selenite on the Se concentration in barley (Hordeum vulgare L.) grain and in alfalfa (Medicago sativa L.) and timothy (Phleum pratense L.) foliage. Applications of 10–20 g Se ha−1 resulted in barley kernels and forage plant Se levels that would be adequate to prevent Se deficiency in most livestock. The highest rate of Se, at 80 g ha−1, resulted in plant Se concentrations of 706 μg kg−1 in timothy. The measured plant Se concentrations, to the same applications, varied from year to year but the responses to applied Se levels were generally in the same proportions. For similar application rates Se concentrations were lower in barley grain than in the forages. Tissue Se levels in the second cuts of alfalfa and timothy were lower than in the first cut. High levels of foliar-applied Se did not result in a carryover effect the following crop year. Annual foliar applications of Se would be required to raise the Se levels in crops into the sufficiency range for livestock feeds. Key words: Selenium content, foliar spray, cereals, forages, Podzol soils

1984 ◽  
Vol 64 (3) ◽  
pp. 403-409 ◽  
Author(s):  
UMESH C. GUPTA ◽  
J. A. MacLEOD

Field experiments were conducted at three locations in Prince Edward Island to determine the effects of various sources of S (Agri-Sul, gypsum, and Urea-Sul) on S concentration of tissue and yields of forages and cereals. Gypsum was effective in increasing the S concentration in plant tissues. Agri-Sul at 10–80 kg S∙ha−1 was generally ineffective in increasing the S concentration of forages and cereals. In the absence of added S (check treatments), the plant tissue S concentrations in alfalfa (Medicago sativa L.) and timothy (Phleum pratense L.) ranged from 0.18 to 0.39 and from 0.14 to 0.27%, respectively. In wheat (Triticum aestivum L.) and barley (Hordeum distichon L.), the S concentrations varied from 0.12 to 0.26 and from 0.13 to 0.20% in the boot stage tissue and grain, respectively, in the check treatments. In general, the S concentration was higher in the boot stage tissue than in the grain. Pea (Pisum sativum L.) seeds and vegetative material from the check treatments contained 0.19–0.24% and 0.17–0.36% S, respectively. Gypsum or Urea-Sul did not increase the yields of forages or cereals. In one instance Agri-Sul slightly increased the alfalfa yield (5–8.5%), but this was not associated with tissue S increases. Plant tissue S levels as low as 0.12–0.18% appeared to be adequate for barley, wheat, timothy, peas, and alfalfa. Key words: Sources of sulfur, tissue S, yields, cereals, forages


2004 ◽  
Vol 84 (1) ◽  
pp. 217-221 ◽  
Author(s):  
D. Spaner and A. G. Todd

Oats (Avena sativa L.) or barley (Hordeum vulgare L.) sown at increasing seeding rates of 23, 45 and 68 kg ha-1 with a timothy (Phleum pratense L.)-alfalfa (Medicago sativa L.) mixture (harvested at cereal soft dough) resulted in increasing forage yields containing decreasing alfalfa, crude protein, P and Ca percentage in the planting year. Barley out-yielded oats by 11% in the planting year. Oats or barley sown at seeding rates up to 68 kg ha-1 do not impede underseeded forage establishment or forage production in the subsequent year in central Newfoundland. The implications of farmer-directed on-farm experimentation are discussed. Key words: Hordeum vulgare L., Avena sativa L., Phleum pratense L, Medicago sativa L., underseeding


1982 ◽  
Vol 62 (1) ◽  
pp. 145-154 ◽  
Author(s):  
UMESH C. GUPTA ◽  
K. A. WINTER ◽  
K. B. McRAE

Two separate field experiments were conducted on several crops to determine the effect of selenium (Se) applied to soils with pH levels between 5.7 and 6.6. Tissue Se levels after a single application of Se and lime, were monitored for up to six cropping years or until the tissue Se fell below 0.1 ppm, the level considered to be necessary for animal nutrition. For applications of 1.12 and 2.24 kg Se/ha, the minimal tissue Se concentration (> 0.1 ppm) was maintained in barley (Hordeum vulgare L.) for two cropping years, but with a very sharp decrease for the first 3 yr. In the case of timothy (Phleum pratense L.), tissue levels greater than 0.1 ppm were maintained for 3 yr at the higher rate of Se without lime and up to 5 yr at high soil pH levels. At the applied rates of 0.28 and 0.56 kg Se/ha, the tissue Se levels above 0.1 ppm in timothy, red clover (Trifolium pratense L.), and alfalfa (Medicago sativa L.) were maintained for one and two cropping years, respectively. In spite of the sharp decrease in plant tissue Se levels, little decrease in total soil Se was noted at rates of 1.12 and 2.24 kg Se/ha after successive croppings of barley and timothy. Although not always significant, liming, in general, increased the plant Se concentration. The Se concentration (log ppm) for tissues (or depletion of Se availability) in the Se-applied plots decreased linearly for at least the first three cropping seasons.


1983 ◽  
Vol 63 (3) ◽  
pp. 455-459 ◽  
Author(s):  
UMESH C. GUPTA ◽  
H. T. KUNELIUS ◽  
K. A. WINTER

In a field study, the residual effects of 1, 2, and 4 kg Se/ha applied as a foliar spray and of 1 kg Se/ha applied to the soil were measured for up to five cropping seasons on yields and Se concentration of alfalfa (Medicago sativa L.), timothy (Phleum pratense L. and barley (Hordeum vulgare L.). Selenium applied as foliar spray reduced yields by 16–37% for the three species in the first year but had no effect in the second and subsequent years. Foliar applications of Se at 1–4 kg/ha in the first year produced alfalfa and timothy containing 27–142 ppm Se, which, when fed to livestock, would cause Se toxicity. Barley grain at these rates contained 4.3–8.4 ppm Se. The tissue Se concentrations of the three species did not exceed 0.6 ppm in the second and subsequent years. The residual effect of 1 kg Se/ha applied to the soil lasted longer on the three species than 1 kg Se/ha applied as foliar spray. Selenium applied to soil or as a foliar spray at 1 kg/ha resulted in tissue concentrations greater than 0.1 ppm Se in forages for two to four cropping seasons, and in barley grain for one to two cropping seasons. At 2 and 4 kg Se/ha, applied as a foliar spray, the tissue Se levels greater than 0.1 ppm were maintained for two to four cropping seasons in barley, alfalfa, and timothy. Tissue Se concentrations were generally higher in timothy than in alfalfa and barley grain. Key words: Forages, barley, selenium, yields, foliar application, podzol soil


1985 ◽  
Vol 65 (3) ◽  
pp. 787-791
Author(s):  
H. A. BURITY ◽  
B. E. COULMAN ◽  
M. A. FARIS

A greenhouse experiment has shown that total nitrogenase activity of alfalfa (Medicago sativa L.) is not significantly affected when grown in association with timothy (Phleum pratense L.), smooth bromegrass (Bromus inermis Leyss) or orchardgrass (Dactylis glomerata L.) except after initial harvest when decreased alfalfa activity was associated with smooth bromegrass or orchardgrass. It was concluded that mixed cultures of alfalfa with timothy, smooth bromegrass or orchardgrass have no effect on alfalfa N2 fixation. The results also suggest the occurrence of N transference from alfalfa to associated grasses. It is speculated that this transfer is not primarily due to the death of roots and nodule tissue (after harvest), but involves some degree of N excretion during the period before initial harvest.Key words: Alfalfa-grass mixtures, N2-fixation, nodule activity, N-transference


Plants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 46
Author(s):  
Noriyuki Ida ◽  
Arihiro Iwasaki ◽  
Toshiaki Teruya ◽  
Kiyotake Suenaga ◽  
Hisashi Kato-Noguchi

Cyatheaceae (tree ferns) appeared during the Jurassic period and some of the species still remain. Those species may have some morphological and/or physiological characteristics for survival. A tree fern was observed to suppress the growth of other ligneous plants in a tropical forest. It was assumed that the fern may release toxic substances into the forest floor, but those toxic substances have not yet been identified. Therefore, we investigated the phytotoxicity and phytotoxic substances of Cyathea lepifera (J. Sm. ex Hook.) Copel. An aqueous methanol extract of C. lepifera fronds inhibited the growth of roots and shoots of dicotyledonous garden cress (Lepidum sativum L.), lettuce (Lactuca sativa L.), and alfalfa (Medicago sativa L.), and monocotyledonous ryegrass (Lolium multiflorum Lam.), timothy (Phleum pratense L.), and barnyardgrass (Echinochloa crus-galli (L.) P. Beauv.). The results suggest that C. lepifera fronds may have phytotoxicity and contain some phytotoxic substances. The extract was purified through several chromatographic steps during which inhibitory activity was monitored, and p-coumaric acid and (-)-3-hydroxy-β-ionone were isolated. Those compounds showed phytotoxic activity and may contribute to the phytotoxic effects caused by the C. lepifera fronds. The fronds fall and accumulate on the forest floor through defoliation, and the compounds may be released into the forest soils through the decomposition process of the fronds. The phytotoxic activities of the compounds may be partly responsible for the fern’s survival.


1983 ◽  
Vol 63 (1) ◽  
pp. 133-139 ◽  
Author(s):  
KARL A. WINTER ◽  
UMESH C. GUPTA

Timothy (Phleum pratense L.) samples from 107 sites throughout Prince Edward Island were obtained at the early heading stage and analyzed for Ca, P, K, Mg, Cu, Mo, S, Mn, Zn and Fe. The mean tissue contents of these minerals were: Ca, 0.25%; P, 0.24%; K, 2.12%; Mg, 0.10%; Cu, 4.5 ppm; Mo, 0.37 ppm; S, 0.12%; Mn, 31.1 ppm; Zn, 26.8 ppm and Fe, 30.5 ppm. When compared with the requirements of cattle and sheep Ca would be deficient for most age and production categories and the mean timothy Ca content was lower than published values. The Ca: P ratio was low at approximately 1:1. Mean Mg content of timothy was low relative to animals' requirements, which, combined with the low Ca and high K content of a number of samples, indicated there was a risk of grass tetany in grazing animals. Most trace elements were barely adequate or deficient relative to the needs of cattle and sheep. Copper, for example, at 4.5 ppm is deficient for cattle but lack of deficiency problems was attributed to correspondingly low Mo and S levels. The need for adequate Ca and P supplementation and the use of a suitable trace-mineralized salt is recommended in formulating diets for dairy cattle, beef cattle, and sheep. Key words: Timothy, forage, minerals, deficiency, cattle, sheep


1974 ◽  
Vol 54 (1) ◽  
pp. 89-104 ◽  
Author(s):  
R. W. SHEARD

Nitrogen, supplied as NH4NO3 to timothy (Phleum pratense L.) and bromegrass (Bromus inermis L.) or as N derived from alfalfa (Medicago sativa L.) growing in association with timothy, enhanced the utilization of surface applications of pelleted, 32P-labelled calcium phosphate. The proportion of the P in timothy derived from a single application of 60 kg P/ha increased from a range of 16% to 21% without N to a range of 38% to 43% with an application of 60 kg N/ha before spring growth and repeated after the first and second harvests. At the first two harvests, growing timothy in association with alfalfa further increased the proportion. The increase was greater at the second harvest and at the lower rates of N, amounting to an increase of one-third at applications of 15 and 30 kg N/ha. The proportion of P in the first harvest of bromegrass which was derived from a surface application was increased 17% to 26% as the rate of P was increased from 40 to 120 kg P/ha; however, N fertilizer as NH4NO3 increased fertilizer P utilization from 17% to 32% as the rate of N was increased from zero to 120 kg N/ha at the 40 kg P/ha rate, and from 26% to 57% with increasing N at the 120 kg P/ha rate. Similar data were obtained when the rates of N application were repeated for the second and third harvests. A relationship, developed between the N concentration in the grass species and the percent utilization of fertilizer P, would suggest that enhancement in utilization of P was, in part, the result of an increase in the assimilated N in the plant. The experiments illustrate that it is imperative to provide adequate N for efficient utilization of surface-applied P by perennial forage grasses.


2015 ◽  
Vol 95 (5) ◽  
pp. 1047-1048
Author(s):  
Y. A. Papadopoulos ◽  
B. R. Christie ◽  
K. B. McRae ◽  
D. Gehl ◽  
S. A. E. Fillmore

Papadopoulos, Y. A., Christie, B. R., McRae, K. B., Gehl, D. and Fillmore, S. A. E. 2015. Pratt timothy. Can. J. Plant Sci. 95: 1047–1048. Pratt timothy (Phleum pratense L.) is an 11-clone synthetic cultivar developed through progeny testing for general combining ability at Agriculture and Agri-Food Canada, Crops and Livestock Research Centre, Charlottetown, Prince Edward Island. Pratt timothy was selected for winter hardiness, plant vigour, plant height, and intermediate maturity (similar to the check cultivar Climax but later than Champ). In Atlantic Canada, Pratt timothy produced more forage than Champ during 3 production years. This cultivar was superior in persistence and re-growth potential with greater production of second-cut herbage.


1970 ◽  
Vol 50 (2) ◽  
pp. 265-267 ◽  
Author(s):  
F. W. CALDER

Rumen fluid from two sheep was used to determine in vitro dry matter digestibilities of 25 samples each from alfalfa hay (Medicago sativa L.) and barley grain (Hordeum vulgare L.). The sheep were fed either a good quality hay ad libitum and 1 kg rolled barley per day, or only the hay ad libitum, in a switchback design. The in vitro dry matter digestibilities of both alfalfa hay and barley were lower (P < 0.01) when the donor animal was fed hay and barley than when fed only hay.


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