The control of silver scurf and development of thiabendazole resistance inHelminthosporium solani as affected by the rate of fungicide applied to potato seed tubers

1994 ◽  
Vol 37 (4) ◽  
pp. 403-411 ◽  
Author(s):  
Sharon M. Hall ◽  
G. A. Hide
Keyword(s):  
Potato Seed ◽  
Silver Scurf ◽  
Seed Tubers

scholarly journals Evaluation of different fungicides applied as seed tuber treatments for the control of potato silver scurf

2005 ◽  
Vol 82 (2) ◽  
pp. 41-48 ◽  
Author(s):  
V. Hervieux ◽  
R. Chabot ◽  
J. Arul ◽  
R.J. Tweddell
Keyword(s):  
Solanum Tuberosum ◽  
Seed Tuber ◽  
Field Trials ◽  
Potato Seed ◽  
Silver Scurf ◽  
Helminthosporium Solani ◽  
Potato Tubers ◽  
Experimental Conditions ◽  
Soil Inoculum ◽  
Seed Tubers

Silver scurf of potatoes (Solanum tuberosum), caused by the fungus Helminthosporium solani, is an important surface-blemishing disease of potato tubers. The objective of the study was to evaluate the efficacy of different fungicides applied to potato seed tubers for control of silver scurf. Field trials were conducted in Québec province in 1998 and 1999. Potato seed tubers infected with H. solani were treated with either talc, fludioxonil, mancozeb, iprodione, thiabendazole, imazalil or azoxystrobin, and planted at three locations in 1998 and two locations in 1999. The results showed that, under our experimental conditions, the fungicides tested, applied as seed treatments, did not significantly influence total and marketable yields as well as silver scurf severity on daughter tubers at harvest and after different storage periods. In addition, this study showed the influence of the experimental locations on silver scurf development and suggests that soil inoculum plays a role in the epidemiology of the disease.

Transmission of Helminthosporium solani from potato seed tubers and effects of soil conditions, seed inoculum and seed physiology on silver scurf disease

1995 ◽  
Vol 124 (2) ◽  
pp. 219-234 ◽  
Author(s):  
D. M. Firman ◽  
E. J. Allen
Keyword(s):  
Weight Loss ◽  
Field Experiments ◽  
Soil Conditions ◽  
Potato Seed ◽  
Silver Scurf ◽  
Moisture Regime ◽  
Helminthosporium Solani ◽  
Seed Tubers ◽  
Soil Moisture Regime ◽  
One Year

SUMMARYThe transmission of silver scurf (Helminthosporium solani) disease of potatoes was examined in field experiments at Cambridge University Farm in 1988–90. Treatment factors examined were seed size, seed age, seed incubation, soil moisture regime and planting date. A laboratory experiment investigated the viability of conidia of Helminthosporium in soil stored under different conditions.Incubation of seed at high humidity before planting increased sporulation of Helminthosporium on seed tubers after planting and fewer conidia were produced from small seed than from larger seed. Delay in planting caused more rapid growth of Helminthosporium on seed tubers after planting.Early planting and late harvesting increased the severity of silver scurf on progeny tubers. Severity of silver scurf was also increased by ageing seed and by incubating seed. Weight loss of potato tubers during storage tended to be greater from treatments with most severe silver scurf in all years but a significant linear regression of weight loss on silver scurf severity was found in only one year out of three from a late harvest. The viability of conidia added to soil was found to decrease rapidly so that by 10 weeks after addition, < 1% of conidia were apparently viable.

EVALUATION DE L’IMPORTANCE RELATIVE DU SOL ET DE LA SEMENCE COMME SOURCE D’INOCULUM DE LA TACHE ARGENTEE DES POMMES DE TERRE AU MOYEN D’ESSAIS DE REPRESSION

1967 ◽  
Vol 47 (6) ◽  
pp. 695-702 ◽  
Author(s):  
Jacquelin Santerre
Keyword(s):  
Cultural Practices ◽  
Inorganic Mercury ◽  
Health Condition ◽  
Potato Seed ◽  
Silver Scurf ◽  
Seed Potatoes ◽  
Mercury Compounds ◽  
Seed Tubers ◽  
Good Surface ◽  
Disease Free

The disinfection of potato seed tubers with formalin, organic and inorganic mercury compounds is useless against silver scurf of potatoes caused by Helminthosporium atrovirens. Although generally good surface disinfectants, these fungicides cannot reach the mycelium of the fungus growing underneath the skin. When conditions are again favorable, the pathogen will grow conidiophores that will bear conidia, the germination of which is not impaired by the previous treatments.Cultural practices such as fallow, crop rotation as well as soil treatments with Lanstan (soil fungicide) or Vapam (soil fumigant) did not reduce the percentage of infected tubers at harvest when used in conjunction with apparently disease-free potato seed tubers.Besides showing the ineffectiveness of disinfecting potato seed tubers, these results indicate that evaluating the true health condition of seed-potatoes according to whether or not the fungus is present on the skin is not to be relied upon, that sorting out visibly infected tubers does not suffice to free a "seed" from the disease, and that cultural practices and chemical soil treatments are useless if the seed-potatoes are already infected, thereby laying emphasis on the infected potato seed tubers as the main source of inoculum for silver scurf.

Age of potato seed-tubers influences protein synthesis during sprouting

1993 ◽  
Vol 89 (2) ◽  
pp. 262-270 ◽  
Author(s):  
G. N. Mohan Kumar ◽  
N. Richard Knowles
Keyword(s):  
Protein Synthesis ◽  
Potato Seed ◽  
Seed Tubers

Determination of optimum tuber planting density in the potato varieties Pentland Squire, Cara, Estima, Maris Piper and King Edward

1992 ◽  
Vol 119 (1) ◽  
pp. 35-44 ◽  
Author(s):  
D. C. E. Wurr ◽  
J. R. Fellows ◽  
E. J. Allen
Keyword(s):  
Complex Analysis ◽  
Seed Tuber ◽  
Tuber Size ◽  
Planting Density ◽  
Potato Seed ◽  
Stem Density ◽  
Seed Tubers ◽  
Net Returns ◽  
Analysis Technique ◽  
The Cost

SummaryThirty-two experiments examining the effects of the weight and within-row spacing of potato seed tubers on graded tuber yields of five varieties were conducted on eight sites from 1980 to 1985. A complex analysis technique was used to combine these data and estimate the optimum tuber planting densities for different ratios of seed cost to small (40–60 mm) and large (60–80 mm) ware value. The same technique could be applied to any other combination of seed cost, ware size and ware value.The optimum tuber planting density decreased with increasing seed-tuber weight. Differences in optimum planting density between varieties were much greater with small (35 g) than with large (105 g) seed tubers and decreased as the cost of seed increased relative to the value of ware. As large ware became worth more than small ware the influence of increasing seed cost on the optimum density was reduced. As the value of large ware increased, net returns increased and the effect of seed cost on net returns was reduced. Mean tuber size decreased with increasing stem density at harvest and at the same stem density was lower in varieties producing more daughter tubers/stem. Changes of mean tuber size (μ) and the spread of yield across size grades (σ) with time were well described by parallel curves in different varieties. It is suggested that in future it may not be necessary to determine optimum tuber planting densities by complex experiments involving several seed-tuber weights and spacings. Instead μ and σ could be estimated from simple experiments and tuber spacings determined by comparison with control varieties.

Effects of Gibberellic Acid (GA3) on Sprouting and Quality of Potato Seed Tubers in Diffused Light and Pit Storage Conditions

2006 ◽  
Vol 6 (4) ◽  
pp. 723-733 ◽  
Author(s):  
Solomon I. Shibairo . ◽  
Paul Demo . ◽  
Jackson N. Kabira . ◽  
Peter Gildemacher . ◽  
Esther Gachango . ◽  
...  
Keyword(s):  
Gibberellic Acid ◽  
Storage Conditions ◽  
Potato Seed ◽  
Seed Tubers ◽  
Diffused Light

Seed Borne Late Blight of Potato

2002 ◽  
Vol 3 (1) ◽  
pp. 14 ◽  
Author(s):  
Mary L. Powelson ◽  
Robin Ludy ◽  
Heather Heather ◽  
Debra A. Inglis ◽  
Babette Gundersen ◽  
...  
Keyword(s):  
Late Blight ◽  
Seed Piece ◽  
Transmission Rate ◽  
Seed Transmission ◽  
Management Program ◽  
Healthy Plant ◽  
Potato Seed ◽  
Stand Establishment ◽  
Seed Tubers ◽  
Healthy Seed

Planting of potato seed pieces infected with Phytophthora infestans can lead to the introduction of late blight within a planting. When infected seed pieces are planted, there are three resulting scenarios: (i) a healthy plant emerges, (ii) no plant emerges because of the rapid decay of the seed piece, or (iii) a symptomatic plant emerges. A major factor favoring stand establishment and seed transmission is the severity of seed piece infection. When infection is severe, stand is compromised and transmission rate is low. When infection is mild, the plant emerges before the seed piece decays and, in some instances, the pathogen makes its way from the seed piece to the plant where a stem lesion is formed. Diseased seed tubers are the principle source of late blight inoculum for infection of healthy seed pieces. Treatment of infected or blighted seed tubers with a seed dressing with activity against P. infestans is not a viable tactic because the products are ineffective against established infections. Conversely, treatment of healthy seed pieces provides a high level of protection against late blight spores that are spread during the seed handling and planting operations. Optimum effectiveness is achieved when products are applied immediately following cutting, as none are effective against established infections. Seed treatment reduces the risk of seed transmission of late blight and enhances stand establishment and plant vigor. This tactic should be an important component of an integrated late blight management program. Accepted for publication 16 January 2002. Published 29 January 2002.

scholarly journals Yield Performance of Potato Seed Tubers After Storage in a Diffuse Light Store (DLS)

2013 ◽  
Vol 6 (1) ◽  
Author(s):  
Jane Muthoni ◽  
J. N. Kabira ◽  
D. Kipkoech ◽  
G. O. Abong ◽  
J. H. Nderitu
Keyword(s):  
Potato Seed ◽  
Diffuse Light ◽  
Yield Performance ◽  
Seed Tubers
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