Sprout inhibition of table stock potatoes with CIPC-treated paper bags     

R. E. Nylund  L. C. Ayres 《American Journal of Potato Research》1964,41(11):341-348

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The influence of mist irrigation on the potato: II. Growth and development     

D. C. Sanders  R. E. Nylund 《American Journal of Potato Research》1972,49(5):187-195

The influence of irrigation method on potato growth and development was assessed during three years. Low volume “mist” irrigation (M), furrow irrigation (F), mist plus furrow (MF) and no irrigation (NI) were compared. During a high and moderate stress season misting maintained the haulm later into the season and increased the proportion of small and medium size tubers. Further during the high stress season misted plots (M and MF) yielded more than NI plots.  相似文献   

The influence of mist irrigatioin on the potato: III. Nutrient content of leaves     

D. C. Sanders  R. E. Nylund  E. C. Quisumbing 《American Journal of Potato Research》1972,49(6):218-226

The influence of irrigation method on nutrient content of potato leaves throughout the season was assessed during three years. Low gallonage “mist” irrigation (M), furrow irrigation (F), mist plus furrow (MF), and no irrigation (NI) were compared. Leaf blades and petioles from Kennebec (1967, 1968, 1969) and Irish Cobbler (1968, 1969) plants were analyzed for P, K, Ca, Mg, Fe, Zn, Mo, Mn, Cu, B and N. Levels of Mo, Mn, Cu and B did not differ either between treatments or during the season. Leaves from different irrigation methods did not differ consistently in levels of N, K, Mg, Ca or Fe. However, during the latter part of two seasons NI plants contained less P and K and more Fe than M or MF plants. F plants were similar to NI plants in nutrient content except that P was lower in the latter. No matter what the irrigation method, N declined as plants matured. Irrigation treatment did not influence the K or Fe levels of petioles consistently. On several sampling dates MF plants were intermediate. Leaves and petioles of M and MF plants consistently contained more Zn throughout all three seasons than non-irrigated or furrow irrigated plants and, in conctrast to the latter, Zn content did not decline as plants matured.  相似文献   

Chemical weed control in potatoes     

R. E. Nylund  D. C. Sanders  E. Quisumbing 《American Journal of Potato Research》1971,48(6):214-221

Nine herbicide treatments were applied to potatoes grown at three locations in each of 3 years. The locations were characterized by widely different soil types—silty clay loam, sandy loam, and muck—and by differences in rainfall and temperatures during the growing season. None of the herbicide treatments applied pre-emergence gave adequate weed control at all locations and/or in all years. EPTC at 6 lb per acre (6.72 kg/ha) gave excellent weed control on both mineral soils but not on muck. Metabromuron at 4 lb per acre (4.48 kg/ha gave excellent weed control only on the low organic matter sandy loam. Propachlor at 6 lb. (6.72 kg/ha) and 2 lb amiben plus 3 lb propachlor (2.24 plus 3.36 kg/ha) gave variable control. Four herbicides: 1 lb paraquat (1.12 kg/ha), 2 lb linuron (2.24 kg/ha), 6 lb dinoseb (6.72 kg/ha) and 6 lb dinoseb plus 2.25 dalapon (6.72 plus 2.52 kg/ha) applied at potato plant emergence, when weeds were in the 2–6 leaf stage, also gave variable control but as a group generally gave better control than the pre-emergence herbicides, particularly on muck soil. The effectiveness of herbicides applied at potato plant emergence was less affected by soil type than those applied pre-emergence but was affected by the degree of weed emergence. On muck soil, weeds generally emerged well before “at emergence” herbicide treatments were applied. Tuber yields were not directly affected by the herbicides, but were reduced where weed control was inadequate. Tuber specific gravity and chip color were unaffected by the herbicides.  相似文献   

The influence of mist irrigation on the potato I. Micro-environment and leaf water relations     

D. C. Sanders  R. E. Nylund 《American Journal of Potato Research》1972,49(4):123-137

The influence of low gallonage “mist” irrigation on the following parameters were measured: leaf, air and soil temperature; and soil moisture, relative turgor and stomatal aperature. Misted canopies had lower leaf, air and soil temperature and higher soil moisture than the non-irrigated plants. Stomata of misted plants did not close as rapidly as those of non-irrigated plants.  相似文献   

The influence of potassium fertilizer application on tuber yield and mineral element content of potato petioles during the growing season     

D. G. Holm  R. E. Nylund 《American Journal of Potato Research》1978,55(5):265-273

Potassium was applied at rates equivalent to 0, 135, and 250 pounds per acre (0, 151, 180 kg K/ha) to study the effect of soil applied K on tuber yields and concentration of mineral elements in the petioles of potato plants during growth both measured at 14 day intervals. Petioles were analyzed for N, P, K, Ca, Fe, Mg, Zn, Cu, Al, Mn, and B. Seasonal trends in petiolar K content were highly correlated with tuber bulking regardless of rate of K application. Increasing K application rates generally increased petiolar levels of K and Zn (early in the season) and decreased the levels of N, Mg, Ca, Zn (late in the season), Al, Fe, Cu, and B in the petioles. Concentrations of P and Mn were unaffected by K applications. Seasonal trends in the mineral element content of petioles were not influenced by K. Results indicate that a prediction model for tuber yield based upon trends in the K content of petioles is valid under differing soil levels of K.  相似文献   

Characterization of <Emphasis Type="Italic">Dickeya</Emphasis> strains isolated from potato and river water samples in Finland     

Jaana Laurila  Virpi Ahola  Ari Lehtinen  Tiina Joutsjoki  Asko Hannukkala  Anne Rahkonen  Minna Pirhonen 《European journal of plant pathology / European Foundation for Plant Pathology》2008,122(2):213-225

Plant pathogenic enterobacteria in the genera Pectobacterium and Dickeya (formerly classified as Erwinia) were isolated from diseased potato stems and tubers. The isolated bacteria were identified as P. atrosepticum, P. carotovorum and pathogens in the genus Dickeya with PCR tests. Furthermore, Dickeya strains were isolated from river water samples throughout the country. Phylogenetic analysis with 16S-23S rDNA intergenic spacer sequences suggested that the Dickeya strains could be divided into three groups, two of which were isolated from potato samples. Phylogenetic analysis with 16S rDNA sequences and growth at 39°C suggested that one of the groups corresponds to D. dianthicola, a quarantine pathogen in greenhouse cultivation of ornamentals, while two of the groups did not clearly resemble any of the previously characterised Dickeya species. Field trials with the strains indicated that D. dianthicola-like strains isolated from river samples caused the highest incidence of rotting and necrosis of potato stems, but some of the Dickeya strains isolated from potato samples also caused symptoms. The results showed that although P. atrosepticum is still the major cause of blackleg in Finland, virulent Dickeya strains were commonly present in potato stocks and rivers. This is the first report suggesting that Dickeya, originally known as a pathogen in tropical and warm climates, may cause diseases in potato in northern Europe.  相似文献   

Carrot Pathogen ‘<Emphasis Type="Italic">Candidatus</Emphasis> Liberibacter solanacearum’ Haplotype C Detected in Symptomless Potato Plants in Finland     

Minna Haapalainen  Satu Latvala  Marika Rastas  Jinhui Wang  Asko Hannukkala  Minna Pirhonen  Anne I. Nissinen 《Potato Research》2018,61(1):31-50

‘Candidatus Liberibacter solanacearum’ (CLso) haplotype C, a bacterial pathogen transmitted by the carrot psyllid Trioza apicalis, causes yield losses in carrot production. Due to concerns that this pathogen might also threaten potato (Solanum tuberosum) production, the occurrence of CLso in cultivated and volunteer potatoes in Tavastia Proper and Satakunta regions of Finland was studied. Volunteer potato plants were found in 13 of the 27 inspected carrot fields. Of the 148 potato samples tested by PCR, eight volunteer potato plants and one cultivated potato grown at the edge of a carrot field were found to be CLso positive. The PCR products obtained from these potatoes with primers OA2/OI2c, LpFrag4-1611F/LpFrag4-480R and CL514F/CL514R all showed 100% sequence identity to CLso haplotype C. This is the first observation of CLso haplotype C in field-grown potatoes. In addition, transmission experiments were performed. Attempts to transmit CLso into potato with carrot psyllids were not successful; however, CLso haplotype C was transmitted from infected carrots to potato plants by leaf grafting and by phloem connection formed by dodder, a parasitic plant, and found to survive in the potato plants for several weeks after transmission. However, the bacterial colonisation progressed slowly in the potato phloem and the amount of bacteria detected was low. The plants produced from the daughter tubers of the CLso-positive potato plants were all CLso negative, suggesting that CLso haplotype C was not able to pass to the daughter plants. None of the CLso-positive potatoes inoculated in greenhouse or collected from fields showed symptoms characteristic of zebra chip disease, associated with CLso haplotypes A and B.  相似文献   

Genotyping of Tenacibaculum maritimum isolates from farmed Atlantic salmon in Western Canada          下载免费PDF全文

K Frisch  S B Småge  Ø J Brevik  H Duesund  A Nylund 《Journal of fish diseases》2018,41(1):131-137

Mouthrot infections (bacterial stomatitis) have a significant impact on the Atlantic salmon aquaculture industry in Western Canada due to economic losses and fish welfare. Bacteria isolated from lesions in the field have been identified as Tenacibaculum maritimum. Mouthrot is different to classical tenacibaculosis, which is most commonly associated with ulcerative lesions, frayed fins and tail rot. The marine fish pathogen T. maritimum is found worldwide; however, in Western Canada, the knowledge of the genetic profile of T. maritimum is limited. This study looked at increasing this knowledge by genotyping T. maritimum isolates collected from Atlantic salmon from farms in Western Canada. These genotypes were compared to other species of the genus Tenacibaculum, as well as other known sequence types within the species. The Western Canadian isolates belong to two new sequence types within the T. maritimum species. Phylogenetic analysis shows that the isolates form a distinct branch together with T. maritimum NCIMB 2154^T separate from other Tenacibaculum type strains, and they are most closely related to strains from Norway and Chile.  相似文献   

Experimental induction of mouthrot in Atlantic salmon smolts using Tenacibaculum maritimum from Western Canada          下载免费PDF全文

K Frisch  S B Småge  C Vallestad  H Duesund  Ø J Brevik  A Klevan  R H Olsen  S T Sjaatil  D Gauthier  B Brudeseth  A Nylund 《Journal of fish diseases》2018,41(8):1247-1258

Mouthrot, or bacterial stomatitis, is a disease which mainly affects farmed Atlantic salmon, (Salmo salar, L.), smolts recently transferred into salt water in both British Columbia (BC), Canada, and Washington State, USA. It is a significant fish welfare issue which results in economic losses due to mortality and antibiotic treatments. The associated pathogen is Tenacibaculum maritimum, a bacterium which causes significant losses in many species of farmed fish worldwide. This bacterium has not been proven to be the causative agent of mouthrot in BC despite being isolated from affected Atlantic salmon. In this study, challenge experiments were performed to determine whether mouthrot could be induced with T. maritimum isolates collected from outbreaks in Western Canada and to attempt to develop a bath challenge model. A secondary objective was to use this model to test inactivated whole‐cell vaccines for T. maritimum in Atlantic salmon smolts. This study shows that T. maritimum is the causative agent of mouthrot and that the bacteria can readily transfer horizontally within the population. Although the whole‐cell oil‐adjuvanted vaccines produced an antibody response that was partially cross‐reactive with several of the T. maritimum isolates, the vaccines did not protect the fish under the study's conditions.  相似文献