Micro determination of Nitrogen in Plant Tissues

Mitchell, H. L.

doi:10.1093/jaoac/55.1.1

Cited by 21 publications

(18 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For the proximate analysis, moisture was determined using the method described by Lovell (1974); crude protein by the semi-micro kjeldahl digestion and distillation (Mitchell 1972); crude fat by the soxhlet ether extraction method (Maynard 1970); crude fibre by successive digestion with dilute acid and alkali (Association of Official Agricultural Chemists 1945); ash by using an ashing furnace (Maynard 1970); and calcium and phosphorus as described by Lovell (1974); nitrogen free extract (NFE) was computed by taking the sum of values for crude protein, crude fat, ash and crude fibre and subtracting this from 100 (Maynard et al 1979).…”

Section: Experimental Designsupporting

confidence: 87%

The effects of supplemental feeds containing different protein: energy ratios on the growth and survival of Oreochromis niloticus (L.) in brackish water ponds

Fineman-Kalio

Camacho

1987

Aquaculture Res

View full text Add to dashboard Cite

Abstract. A trial was conducted in 30 earthen ponds of approximately 100 m2 to evaluate the effects of nine supplemental feeds containing different protein: energy ratios on the growth and survival of Oreochromis niloticus (L.) in brackish water ponds. The formulated feeds had protein levels of 20%, 25% and 30% each at three energy levels of 3000 kcal, 3500 kcal and 4000 kcal. There was a control (diet 0) with no feeding and mean weight gain, growth rate, feed conversion rate and survival rate were determined. Fingerlings were acclimated from 0 to 29 ppt salinity before the trial and 20% of fish in each treatment were sampled every 30 days to monitor growth changes and adjust the feed. Mean weight gain was significantly different as follows: 30%:4000 kcal (102·21 g); 30% :3000 kcal (93·24g); 25%:3000 kcal (89·79g); 30%:3500 kcal (83·42g); 25%:4000 kcal (78·80g); 25%:3500 kcal (78·13g); 20%:3000 kcal (76·50g); 20%:4000 kcal (71·05g); 20%:3500 kcal (69·68 g) and control (59·11 g). Growth rates were significantly different (P < 0·05) and increased with increasing energy level at the 30% protein feeds but decreased at high energy levels in the 20% and 25% protein feeds. Feed conversion was significantly different due to interaction between protein and energy levels in the feeds, and was better at the 30%:3500 kcal feed, with a feed conversion of 1·55. Survival rates were not significantly different (P > 0·05).

show abstract

Section: Experimental Designsupporting

confidence: 87%

The effects of supplemental feeds containing different protein: energy ratios on the growth and survival of Oreochromis niloticus (L.) in brackish water ponds

Fineman-Kalio

Camacho

1987

Aquaculture Res

View full text Add to dashboard Cite

show abstract

“…For analysis of nitrogen, phosphorus, potassium, and sulfur, the samples were dried in a forced air oven at 60 °C (140.0 ºF) and ground through a 40-mesh screen before wet digestion. The digestion for nitrogen analysis was as described by Mitchell (1972). A nitric acid digestion method was used to prepare the leaf samples for potassium, phosphorus, and sulfur analysis (Perkin-Elmer, 1982).…”

Section: Research Reportsmentioning

confidence: 99%

“…A nitric acid digestion method was used to prepare the leaf samples for potassium, phosphorus, and sulfur analysis (Perkin-Elmer, 1982). Nitrogen, phosphorus, and sulfur were analyzed colorimetrically (Mitchell, 1972;Jackson, 1958); and potassium was determined using atomic absorption spectrometry at 766.5 nm (model 3100; Perkin-Elmer Analytical Instruments, Shelton, Conn.).…”

Section: Research Reportsmentioning

confidence: 99%

Managing Orchard Floor Vegetation in Flood-irrigated Citrus Groves

Wright

McCloskey

Taylor³

2003

horttech

View full text Add to dashboard Cite

Several orchard floor management strategies were evaluated beginning in Fall 1993 in a `Limoneira 8A Lisbon' lemon (Citrus limon) grove on the Yuma Mesa in Yuma, Ariz. and in a `Valencia' orange (Citrus sinensis) grove at the University of Arizona Citrus Agricultural Center, Waddell, Ariz. At Yuma, disking provided acceptable weed control except underneath the tree canopies where bermudagrass (Cynodon dactylon), purple nutsedge (Cyperus rotundus), and other weed species survived. Mowing the orchard floor suppressed broadleaf weed species allowing the spread of grasses, primarily bermudagrass. Preemergence (norflurazon and oryzalin) and postemergence (glyphosate and sethoxydim) herbicides were used to control weeds in the clean culture treatment in Yuma. After three harvest seasons (1994-95 through 1996-97), the cumulative yield of the clean culture treatment was 385 kg (848.8 lb) per tree, which was significantly greater than the 332 kg (731.9 lb) and 320 kg (705.5 lb) per tree harvested in the disking and mowing treatments, respectively. In addition, the clean culture treatment had a significantly greater percentage of fruit in the 115 and larger size category at the first harvest of the 1995-96 season than either the disk or mow treatments. At Waddell, the management strategies compared were clean culture (at this location only postemergence herbicides were used), mowing of resident weeds with a vegetation-free strip in the tree row, and a `Salina' strawberry clover (Trifolium fragiferum) cover crop with a vegetation-free strip. The cumulative 3-year yield (1994-95 through 1996-97) of the clean culture treatment was 131 kg (288.8 lb) per tree, which was significantly greater then the 110 kg (242.5 lb) per tree yield of the mowed resident weed treatment. The yield of the strawberry clover treatment, 115 kg (253.5 lb) of oranges per tree, was not significantly different from the other two treatments. The presence of cover crops or weeds on the orchard floor was found to have beneficial effects on soil nitrogen and soil organic matter content, but no effect on orange leaf nutrient content. The decrease in yield in the disked or mowed resident weed treatments compared to the clean culture treatment in both locations was attributed to competition for water.

show abstract

“…Ethylene pro-duction was then measured using a Hewlett Packard 5890 Series II gas chromatograph. A second method for assessing symbiotic effectiveness involved measurement of shoot nitrogen content for plants inoculated with different bacterial isolates using the method of Mitchell (1972). Finally, biomass gain by inoculated plants relative to uninoculated control plants was measured.…”

Section: Symbiotic Effectivenessmentioning

confidence: 99%

NONRANDOM GENOTYPIC ASSOCIATIONS IN A LEGUME— BRADYRHIZOBIUM MUTUALISM

1996

View full text Add to dashboard Cite

Abstract.-Genetically divergent lineages often coexist within populations of the annual legume Amphicarpaea braeteata. At one site dominated by two such lineages (termed biotypes "C" and "S"), isolates of root-nodule bacteria (Bradyrhizobium sp.) were sampled from both hosts and analyzed by enzyme electrophoresis. Symbiont populations on the two plant biotypes were highly distinct. Out of 15 bacterial multilocus genotypes detected (among 51 isolates analyzed), only one was shared in common by the two plant biotypes. Cluster analysis revealed three bacterial lineages (designated I, II, and III), with lineage I found exclusively on biotype C plants, and the two other lineages almost completely restricted to biotype S hosts. Laboratory inoculation tests indicated that lineage I bacteria were strictly specialized on biotype C hosts, forming few or no nodules on plants of the other host biotype. Bacterial lineages II and III were capable of forming nodules on both kinds of plants, but nodule numbers were often significantly higher on biotype S hosts. The nonrandom association between plant and bacterial lineages at this site implies that genetic diversity of hosts is an important factor in the maintenance of polymorphism within the symbiont population.Key words.-Bacteria, Bradyrhizobium, coevolution, legumes, linkage disequilibrium, mutualism, nitrogen fixation, polymorphism, symbiosis.Received April 12, 1994. Accepted September 21, 1994 Although it is widely accepted that host-parasite interactions should generate genetic polymorphism (Haldane 1949;Clarke 1976;Hamilton 1982), the situation is much less clear in mutualistic interactions among species. In host-parasite interactions, parasite specialization on hosts with a particular defense mechanism can result in frequency-dependent disease impact on hosts, leading to stable or cyclic polymorphisms in both species (Lewis 1981;Seger 1988). Law (1985) argued that quite different evolutionary processes should occur in mutualisms. Selection on each species in a mutualism will favor adaptation to the most prevalent phenotype in the other species, because individuals adapted only to rare phenotypes will receive fewer mutualistic benefits given their smaller chance of encountering a suitable partner. As a result, Law suggested that the evolutionary trend toward genotypic specialization thought to typify host-parasite coevolution should generally be lacking in mutualisms. Because polymorphism due to frequency-dependent disease impact requires parasite specialization (Lewis 1981;Seger 1988; Parker 1992a), the absence of such specialization in mutualisms would also imply the absence of any inherent tendency toward genetic polymorphism.However, this argument ignores the fact that different mutualist partners may vary widely in the fitness benefits that they can provide, with the optimal partner unlikely to be identical for all conspecific individuals. Thus, selection in mutualisms may favor intrapopulation specialization, if mechanisms exist to exclude incompatible partners and...

show abstract

Micro determination of Nitrogen in Plant Tissues

Cited by 21 publications

References 0 publications

The effects of supplemental feeds containing different protein: energy ratios on the growth and survival of Oreochromis niloticus (L.) in brackish water ponds

The effects of supplemental feeds containing different protein: energy ratios on the growth and survival of Oreochromis niloticus (L.) in brackish water ponds

Managing Orchard Floor Vegetation in Flood-irrigated Citrus Groves

NONRANDOM GENOTYPIC ASSOCIATIONS IN A LEGUME— BRADYRHIZOBIUM MUTUALISM

Contact Info

Product

Resources

About