Nitrapyrin,terrazole, atrazine and simazine influence on denitrification and corn growth     

Zana C. Somda  S.C. Phatak  H.A. Mills 《Journal of plant nutrition》2013,36(9):1195-1208

In modern agriculture, long‐term soil fertility and crop productivity are maintained by a combination of inorganic fertilizers and pesticide inputs which, in turn, create environmental and health concerns. Therefore, studies were initiated to evaluate two commonly used herbicides (atrazine and simazine) and two biological nitrification inhibitors (nitrapyrin and terrazole) applied with NO₃‐N source fertilizer for their effects on denitrification and on corn (Zea mays L.) growth and yields. Each chemical applied at the rate of 10, 50, or 100 mg a.i. L^‐1 suppressed denitrification of NO₃ ^‐ in a liquid medium inoculated with a Tifton loamy sand in a laboratory study. Nitrapyrin and terrazole selectively suppressed NO₃ ^‐ or NO₂ ^‐ or both reduction while atrazine and simazine suppressed NO₂ ^‐ or N₂O or both reduction. In greenhouse pot culture studies, chemical application resulted in higher percent N recovery relative to the control. When atrazine or simazine was part of the chemical treatment, concentrations of NO₃ ^‐ and NO₂ ^‐ in corn (Zea mays L.) plants increased, and plant growth was restricted due to NO₂ ^‐ toxicity. During two consecutive years of field studies using split‐banded applications of N fertilization with nitrapyrin and terrazole, corn ear yields increased 78% and 25% in the first and second year, respectively. With atrazine and simazine, however, yields increased significantly in the first season only. Mixing either herbicide with nitrapyrin or terrazole had no effect on yields during both seasons.

Chemical Names: atrazine = [2‐chloro‐4‐ethylamino‐6‐isopropylamino‐s‐triazine]; simazine = [2‐chloro‐4,6‐bis(ethylamino)‐s‐triazine]; nitrapyrin = [2‐chloro‐6‐(trichloromethyl)pyridine]; terrazole = [ethoxy‐3‐trichloromethyl‐1,2,4‐thiadiazole].  相似文献   

Nutrient uptake and yield of sweet pepper as affected by stage of development and N form     

Hector R. Marti  Harry A. Mills 《Journal of plant nutrition》2013,36(11):1165-1175

Uptake of NO₃ ^‐, NH₄ ⁺, P, K⁺⁺, Ca⁺⁺ and Mg⁺⁺, as influenced by the stage of plant development and three NO₃ ^‐: NH₄ ⁺ ratios (1: 0, 1: 1, and 0: 1), was determined for sweet pepper (Capsicum annuum L. cv. ‘California Wonder'). Uptake was highest during fruit development and immediately after fruit harvest, indicating that fruit removal promotes nutrient uptake. When NO₃ ^‐ and NH₄ ⁺ were supplied in equal concentrations, NO₃ ^‐ was absorbed more readily. Each increment in NH₄ ⁺ decreased the uptake of K⁺, Ca⁺⁺, and Mg⁺⁺ by fruit tissue, while no significant effect on the N and P content of the fruit was observed. Ammonium nutrition reduced plant dry weight and fruit yield in comparison to NO₃ ^‐. Results from this study suggest that NO₃ ^‐ is the preferred N form, and that fertilizer application should be scheduled according to specific physiological stages to maximize nutrient uptake. Nutrient content of vegetative tissue was not indicative of potential yield.  相似文献   

Calcium uptake and concentration in bell pepper plants as influenced by nitrogen form and stages of development     

Hector R. Marti  Harry A. Mills 《Journal of plant nutrition》2013,36(11):1177-1185

Calcium uptake by bell pepper (Capsicum annuum L. cv. ‘California Wonder') varied by stage of plant development and N form supplied (NO₃ ^‐NH₄ ⁺ ratios: 1:0, 3:1, 1:1, 1:3, and 0:1) in a hydroponic study. Uptake of Ca⁺⁺ was highest at bloom and during fruit expansion, making the fruit development stage the highest demand period. Calcium uptake declined with each increasing increment of NH₄ ⁺ relative to NO₃ ^‐ supplied, although fruit yield was not significantly reduced until the ratio of NH₄ ⁺ to NO₃ ^‐ exceeded 50%. Tissue Ca⁺⁺ levels in the blossom‐end of the fruit were reduced whenever NH₄ ⁺ was included with N supplied. Vegetative yield of plants followed the same trend as that observed for total fruit dry weights. Our results indicate that pepper yields are higher when NO₃ ^‐ is the predominant form of N. Also, these results strongly suggest that Ca⁺⁺ fertilizer applications should precede the bloom period and continue during fruit development to ensure adequate Ca⁺⁺ availability for fruit development.  相似文献   

Effect of N‐form on growth and nutrient content of creeping bentgrass 1     

James N. McCrimmon  Harry A. Mills  Keith J. Karnok 《Journal of plant nutrition》2013,36(8):1235-1252

Abstract

The primary nitrogen forms utilized by plants are ammonium and nitrate. Although the importance of nutrients other than nitrogen for proper turfgrass growth is well established, the amounts of these nutrients in the plant tissue in relation to the use of different N‐forms has not been clearly documented. This study was conducted under greenhouse conditions to determine the effect of N‐form and cutting regime on growth, macronutrient, and micronutrient content of creeping bentgrass (Agrostis palustris Huds. ‘Penncross'). Treatments consisted of 100% NO3^? (calcium nitrate), 100% NH₄ ⁺ (ammonium sulfate), and a 50:50 ratio of NH₄ ⁺:NO₃ ^?. Half the turfgrass plants were maintained at a height of 1 cm (cut), while the other half of the plants were not cut until the end of the study (uncut). The uncut 50:50 treatment yielded the highest shoot, verdure, and total plant dry matter, while the uncut NO₃ ^? treatment produced the highest root dry matter. The uncut NH₄ ⁺ treatment yielded the least shoot, root, and total plant dry matter. Plants of the uncut NO₃ ^? treatment had greater accumulation of macronutrients in the shoot and root tissue compared to plants of the NH₄ ⁺ treatment. The uncut NO₃ ^? and 50:50 treatments had higher total accumulation of micronutrients compared to the uncut NH₄ ⁺‐treated plants. The cut NO₃ ^? treatment resulted in the highest macronutrient and micronutrient contents in the root tissue in comparison to other cut treatments. The cut treatments had the highest percentage accumulation of nutrients in the verdure tissue, while the uncut treatments had the highest percentage accumulation of nutrients in the shoot tissue.  相似文献   

Injury of leatherleaf fern and tomato from volatilized ammonia after fertilizer application     

A. W. Schumann  H.A. Mills 《Journal of plant nutrition》2013,36(3-4):573-593

Abstract

A commercially blended 7–2–11 fertilizer containing 27 g ? kg^‐1 soluble ammoniacal nitrogen (NH₄‐N) was evaluated for ammonia (NH₃) volatilization and injury to leatherleaf fern (Rumohra adiantiformis) and an indicator plant, tomato (Lycopersicon esculentum). Closed system laboratory incubation studies on pH‐buffered sand medium indicated a very highly significant response (p≤0.001) of NH₃ volatilization to sand pH. The greatest risk from NH₃ emissions at pH 8.6 and 32°C appeared to be in the 5 to 70 hour period after fertilizer application. Gypsum (CaSO₄) did not affect NH₃ volatilization. Ammonium nitrate (NH₄NO₃) was identified as the main source of NH₃ volatilization from this fertilizer formulation, while on an equal mass basis, ammonium sulphate [(NH₄)₂SO₄] was more important. Both tomato and immature leatherleaf fern fronds were highly sensitive to volatilized NH₃ from the fertilizer. A critical phytotoxic NH₃(aq) concentration in sand solution of 0.14 mM was estimated for immature fern fronds. Mature fern fronds were significantly more tolerant of NH₃ emissions, which may explain their observed resistance to NH₃ injury in the field. Assessment of selected soil and irrigation water pH's from a leatherleaf fern growing area in Florida indicated a strong likelihood that volatilized NH₃ injury to foliage can occur under field conditions.  相似文献   

Effect of nitrogen form during the flowering period on zucchini squash growth and nutrient element uptake     

William O. Chance III  Zana C. Somda  Harry A. Mills 《Journal of plant nutrition》2013,36(3):597-607

Zucchini squash (Cucurbita pepo L. cv. Green Magic) plants were grown hydroponically with nitrate (NO₃):ammonium (NH₄) ratio of 3:1 until the onset of flowering when the plants were assigned to four NO₃:NH₄ ratio (1:0, 1:1, 1:3, or 3:1) treatments. Changing the original nitrogen (N) form ratio significantly affected plant growth, fruit yield, nutrient element, and water uptake. Growth of plants was better when NO₃‐N (1:0) was the sole form of N than when NH₄‐N was part of the N treatment. Fruit yields for plants fertilized with 1:0 or 1:3 N‐form ratio were double those of plants grown continuously with 3:1 N ratio. The largest leaf area and plant water use were obtained with 1:0 N ratio treatment Total uptake of calcium (Ca), magnesium (Mg), and potassium (K) decreased with increasing NH₄‐N proportion in the nutrient solution which suggest NH₄‐N was competing with these cations for uptake. The results also demonstrated that growers may increase fruit yield by using a predominantly NO₃‐N source fertilizer through the vegetative growth stage and by shifting the NO₃:NH₄ ratio during the reproductive phase.  相似文献   

Nutrient accumulation in leaf tissue of rapid‐cycling brassuca oleracea responds to increasing sodium selenate concentrations     

Dean A. Kopsell  William M. Randle  Harry A. Mills 《Journal of plant nutrition》2013,36(7):927-935

Brassica oleracea L. are important economic vegetables, and are capable of selenium (Se) enrichment to enhance human nutrition and health. Because Se enrichment may influence the nutrient balance of this crop, a study was done to test the effects of selenate‐Se on plant nutrients. Plants of a rapid‐cycling B. oleracea population were grown in nutrient solutions amended with Na₂SeO₄at 0.0, 3.0, 6.0, and 9.0 mg L^‐1. Leaf tissue was then analyzed for nutrient content. Boron (B) (P=0.01), iron (Fe) (P=0.01), and phosphorus (P) (P=0.01) content decreased, while Se (P=0.01), sulfur (S) (P=0.01), and potassium (K) content (P=0.01) increased with increasing selenate‐Se treatments. Significant quadratic responses were found for magnesium (P=0.01) and molybdenum (P=0.01). No significant differences in leaf fresh or dry weight were detected. Changes in plant nutrient content can be expected when Brassicas are enhanced for delivery of beneficial organic Se.  相似文献   

Analysis of BioOne Journal Collections: Their Quality,Indexing Coverage,and Scholarly Content     

Lutishoor Salisbury  Carolyn Mills 《Journal Of Agricultural & Food Information》2013,14(2):113-123

This study examined the 130 current full-text titles in the BioOne.1 and BioOne.2 collections to determine whether they are peer-reviewed, contain book reviews, and are supplied by document delivery vendors. We identified indexing coverage in 11 major databases in agriculture and life sciences: Aquatic Sciences and Fisheries Abstracts (ASFA), AGRICOLA, Biological Abstracts, BIOSIS Previews, CAB Abstracts, Current Contents, Environmental Sciences and Pollution Abstracts, GeoRef, Scopus, ISI Web of Science, and Zoological Record. We concluded that the majority of the titles in BioOne collections are refereed and scholarly, indexed in several of the major indexing and abstracting journals in the field of agriculture and life sciences, and available via several major document delivery vendors. We find both BioOne collections to be valuable, useful, cost-effective journal aggregations.  相似文献   

Report of the late blight investigations committee     

M. E. Gallegly  K. M. Graham  W. R. Mills  J. S. Niederhauser  J. R. Wallin  Carl J. Eide 《American Journal of Potato Research》1960,37(11):399-400

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Parameters for specific detection ofClavibacter michiganensis subsp.sepedonicus in potato stems and tubers by multiplexed PCR-ELISA     

Dallice Mills  Brian W. Russell 《American Journal of Potato Research》2003,80(4):223-233

A multiplex PCR-ELISA protocol for detection ofClavibacter michiganensis subsp.sepedonicus (Cms) was developed that is based on primers for amplification of three single-copy, unique DNA sequences, Cms50, Cms72, and Cms85. The three sequences were simultaneously amplified from the genomes of all 42 strains of Cms that were tested including variant mucoid forms, but not from strains representing five related subspecies, andRathayibacter rathayi andRhodococcus faciens. The lowest limit of detection by gel electrophoresis was estimated to be approximately 300 CFU per mL when cells were spiked into potato core fluid, but sensitivity increases approximately 10-fold using PCR-ELISA. Inclusion of a sea anemone DNA fragment engineered so it could be amplified from the Cms72 primer set provided the simultaneous signal that the system functioned properly when any sample was free of the pathogen. The addition of hydrolyzed casein to the reaction mix was demonstrated to markedly reduce or eliminate inhibition of PCR by plant cell components or contaminants. Multiplex PCR-ELISA detection of Cms was determined to be verifiable for analysis of both stems and tubers based on the amplification of multiple sites in its genome, it provides absolute specificity, and it was more sensitive than detection based on gel electrophoresis of PCR products and serological approaches.  相似文献