| Title |
Investigators | Department | Objectives | Approach Keywords | Progress Reports | Impact Statements | Publications | |
Project * COL00710 | |
| Title | Improved potato yield and quality through disease suppression and optimum certified seed potato production techniques |
| Investigator(s) | Davidson, RD; |
| Department | Horticulture and Landscape Architecture |
| Objectives | 1) To develop a better understanding of various potato diseases under Colorado conditions and to develop and implement disease suppression control strategies through a best management practices approach. 2) To improve certified seed potato production techniques and certification detection methods to control diseases and improve yield and quality of certified seed stocks produced in Colorado. 3) To support the development of potato cultivars for Colorado by evaluation of new germplasm for specific disease reactions to several pathogens. |
| Approach | 1) Chemical control agents, cultural practices, soil amendments, crop rotation and cultivar resistance will be evaluated. Season long foliar fungicide programs for control of early blight will be conducted annually. Other chemistries will be evaluated against a variety of pathogens/disease complexes including: powdery scab, pink rot, Rhizoctonia, silver scurf, Fusarium spp., Erwinia spp., and early blight tuber decay. 2) Projects, both small plot and grower controlled large plot designs, will be utilized to examine various production techniques related to certified seed production with the express purpose of managing and eliminating, if possible, certain disease issues. Diseases include potato leafroll virus, PVY, PVX, PVS, blackleg and bacterial ring rot. Improved yields and quality of certified seed produced in Colorado is the ultimate goal. 3) Disease evaluations for the new germplasm developed by the Cultivar Development Program will continue. Advanced selections will be screened both in the field and in the greenhouse for resistance and symptom expression with the ultimate goal of providing needed information to the growers via cultivar management profiles. |
| Keywords | potato, potato diseases, cultivar development |
| Progress Reports | |
| 2000 | Reaction of advanced clones from the Colorado Cultivar Development Program to specific diseases is one of the primary objectives of this research. In 2000, seven advanced clones were evaluated for their response to potato leafroll and twenty seven clones and/or cultivars for their response to bacterial ring rot. This project has been ongoing for several years and check or control cultivars are used as comparisons in these evaluations. All of the advanced selections checked for leafroll had adequate symptom expression to the disease. In addition, in-field spread of the virus was consistent and high among the clones, ranging from 58 to 94% as compared with the check cultivars in the range of 0 to 85%. All of the advanced selections fit into the high category for leafroll spread. They also all demonstrated symptoms to potato virus Y infection, another virus which the clones will be evaluated against in the future. Each of the twenty seven clones and/or cultivars screened for bacterial ring rot symptom expression did demonstrate ring rot in the plots. Most of the material screened had adequate symptom expression and the timing of the expression was well within the parameters set by the Certification Program for identifying bacterial ring rot in the field. However, two clones and two cultivars, CO92059-8, TC1675-1, Crispin and Huckleberry did express few or no symptoms and the symptoms expressed were mild. Each of these clones needs further evaluation prior to acceptance and release to the growers. |
| 2001 | Specific disease reactions of advanced potato clones from the Colorado Cultivar Development Program must be obtained before release of any clones to the potato industry. In 2001, sixteen advanced clones were evaluated for their reaction to potato leafroll virus, twenty five for their reaction to bacterial ring rot and thirty five for their reaction to the storage rots; Fusarium spp., Erwinia carotovora, and Alternaria solani. All but two advanced selections demonstrated adequate symptom development to leafroll. Natural in-field spread of leafroll was low to medium this year with only one clone demonstrating high levels of leafroll compared to the check cultivars. Bacterial ring rot expression was good for all but three clones. Two of the clones, NDC5281-2R and TC1675-1RU, have been tested for three years and still show very low symptom expression. Less than 15% of the plants demonstrated bacterial ring rot within 100 days after planting. While this is low, the clones do express good disease symptoms well within the 90 days after planting time frame and thus, should be released to growers with a caution about disease reaction. Finally, several advanced selections with resistance to storage rots have been screened for two years. Five of these selections show high levels of resistance to both Fusarium spp. and Erwinia carotovora and will be used as parents in further breeding as well as having their horticultural characteristics evaluated. |
| 2002 | Nineteen advanced clones were evaluated for their reaction to potato leafroll virus and PVY, fifty eight for their reaction to bacterial ring rot, thirty two for their reaction to powdery scab, and forty for their reaction to storage rots caused by Fusarium spp., Erwinia carotovora , and Alternaria solani. Results varied dramatically by clone and disease screened. Regarding leafroll, CO94019-1R did not show any visible plant symptoms after inoculation for the second year in a row. An additional clone, VC1015-1R/Y also did not demonstrate symptoms. These two will be tested for one more year. Natural-in-field spread of leafroll was overall quite high in the plots in 2002 with most clones exhibiting high to very high spread rates. All clones tested demonstrated typical symptoms to PVY with one clone, CO95077-3R, having very high spread of PVY within the plots. Bacterial ring rot testing showed that all but six clones developed in Colorado had adequate symptoms within an appropriate time frame to the disease. The six clones, CO95051-7W, VC1009-1W/Y, VC1015-1R/Y, VC0967-5R/Y, VC1002-3W/Y and CO93037-6R, ranged from low or late symptom development to no symptom development and will be tested again in 2003. Results from the powdery scab trials indicated that were some clones exhibited good resistance to scab lesions. However, often this did not translate into a low level of root galling from the organism. Finally, many clones with potential resistance to the storage rots are still demonstrating adequate control. One clone, CO96197-3RU, has good resistance to both Fusarium and Erwinia, but does show an elevated risk of early blight tuber decay. Full assessments for each clone tested will be collated and distributed to the leader of the cultivar development program and the grower cooperators. |
| 2003 | Evaluation of advanced clones being developed by the Colorado cultivar development program for specific disease reactions is critical for grower acceptance and production management. In 2003 eighteen advanced clones were evaluated for their reaction to potato leafroll virus and PVY, sixty nine for their reaction to bacterial ring rot, thirty one for their reaction to powdery scab, and twenty three for their reaction to various storage rots. As usual, results varied by clone and disease screened. Results from the leafroll and PVY evaluations are pending. Bacterial ring rot testing demonstrated that most clones developed adequate visual symptoms to the disease within an appropriate time frame. Two clones, CO93037-6R and CO94019-1R did not demonstrate any symptoms. CO93037-6R has been dropped from further consideration or release because of this lack of expression. CO94019-1R will be tested an additional year. Powdery scab trials indicated several test clones with good resistance to the disease. One clone, CO89097-2R has shown excellent yields with little or no powdery scab symptoms. Growers are finding similar results and partially based upon data from this project have decided to ask Colorado State University to release, name and protect (under Federal Plant Variety Protection) this clone. Clones with potential resistance to storage rots are still demonstrating adequate control. One clone, VC0967-2R/Y has consistently shown good resistance to Fusarium and Erwinia spp. Colorado producers will be allowed to grow this clone as seed under the experimental category for the first time in 2004. Two other clones, VC0967-5R/Y and VC1002-3W/Y are also scheduled for initial release to the growers this coming year. Finally, a rating system has been put in place for each of the diseases examined to assist in making appropriate decisions regarding whether the various clones will be released. The rating system ranges from 1-5 with 1 being poor symptom expression and 5 being excellent expression. Full assessments for each clone tested are collated, ratings developed, and results distributed to the leader of the Colorado cultivar developement program and grower cooperators. |
| 2004 | In 2004, twenty advanced clones were evaluated for their disease reaction to potato leafroll virus and PVY, forty four for their reaction to bacterial ring rot, twenty two for their reaction to powdery scab, and thirty plus for their reaction to various storage rots. Results varied by clone and disease screened with some clones demonstrating high levels of either tolerance or resistance to certain diseases. Further work will be needed to evaluate these lines. During this progress report, however, it is appropriate to discuss the release of two cultivars which have come through the full disease screening profile, AC89536-5RU (Rio Grande Russet) and CO89097-2R (Colorado Rose). Federal PVP has recently been applied for with each cultivar. Both cultivars demonstrate excellent mid level resistance to the virus problems potato leafroll and PVY. In addition, Rio Grande Russet has overall good storage characteristics accompanied by high yield while Colorado Rose shows moderate susceptibility to powdery scab, an improvement over the current red cultivars being grown. Recent post harvest results from the certified seed acreage grown in Colorado have shown very favorable readings for each of these cultivars. It is expected that these cultivars will continue to climb in acreage and prominence within their respective categories. These two clones indicate that the Cultivar Development Program as well as the growers in Colorado are using the disease profile information generated to make better decisions about which cultivars will be developed and planted on the existing acreage. |
| 2005 | Advanced clones developed by the Colorado Cultivar Development program are evaluated for numerous traits prior to release to producers. Examining and rating these clones for susceptibility and expression to the major potato pathogens and subsequent diseases of concern is critical for grower acceptance. In 2005, 58 advanced clones from the Colorado program and the Western Regional programs were evaluated for their reaction to bacterial ring rot. Additionally, up to 22 clones were evaluated for their reaction to potato leaf roll virus and PVY in the field and for their reaction to Fusarium and Erwinia spp. in the tubers, while 36 clones were examined for susceptibility to powdery scab. Clones varied in their reaction to these diseases with some showing excellent tolerance or resistance to specific diseases. The challenge will be to appropriately report on these reactions so that growers can make proper decisions about whether or not to use certain clones in their own operations. It is of note, that for the last several years, the advanced clones that have been released to the grower community have been widely accepted and have shown few major disease problems. Results from the Colorado certified seed potato program continue to show that the clones and cultivars released since the inception of this research program have continued to demonstrate low levels of disease. Acceptance by the grower is no longer a matter of uncontrollable disease issues, but now one of how well a clone or cultivar fits within any given market niche. Colorado producers are also demanding more disease profile information to help in making good management decisions about which cultivars will be planted on high value land with limited water resources. |
| 2006 | Numerous advanced clones were evaluated for their reaction to potato diseases. These diseases included: potato leafroll virus, PVY, bacterial ring rot, powdery scab, and the storage rots caused by Fusarium, Erwinia carotovora, and Alternaria solani. Clonal information was developed and reported to both the Cultivar Development Program and to the producers of these new clones. Certain clones were dropped from the cultivar program when disease reactions were inadequate and/or latent. During the last five years, six cultivars were released to the growers and are currently undergoing registration under Federal Plant Variety Protection. These clones are: Purple Majesty, Mountain Rose, Rio Grande Russet, Colorado Rose, Canela Russet, and Rio Colorado. Each of these clones has distinct advantages over other's of the same category regarding disease reactions. Specifically, Rio Grande Russet shows little damage from powdery scab even having extremely low root gall ratings. All of these clones have excellent field characteristics and show low levels of virus spread in-field, even under very challenging conditions. This information has been incorporated into the cultivar management profiles for each cultivar. |
| Impact | |
| 2000 | This research is critical to the needs of the Cultivar Development Program in that it aids in choosing the appropriate advanced selections for release into the general certification program. Growers and the Potato Certification Service have found that ignoring reactions to critical diseases can cause significant impact on farms under disease situations and can cripple a clone or cultivar soon after release. This in turn can cause major financial impact to both the growers and the Cultivar Development Program. |
| 2001 | Information generated by this research is used to help determine which advanced clones should be released to the potato industry. Growers and the Colorado Potato Certification Service have found that ignoring a clone's reaction to serious diseases can cause significant impact on farms under pressure from these diseases and can cripple the potato industry's use of a clone or cultivar soon after release. This creates a situation which is both costly and detrimental to the growers and the Colorado Cultivar Development Program. |
| 2002 | Colorado's certified seed potato program recorded a total of 7,884 acres of Colorado developed cultivars grown in 2002 representing 53% of the seed acreage entered into the program. Yields were at an all time high averaging 390 cwt/acre for the overall Colorado potato industry with seed growers averaging approximately 20% more in yield per acre. At an average price of $10/cwt for certified seed and an output of around 200 cwt/acre usable as seed, this represents approximately $15.8 million in sales generated by Colorado developed cultivars. Additionally, protected cultivars generated over $160,000 in royalty revenues to support CSU research programs. |
| 2003 | Colorado's certified seed potato program recorded a total of 2800 ha of Colorado developed cultivars or clones representing 47% of the seed acreage accepted in 2003. Yields were excellent with the crop demonstrating relatively low levels of disease. This project assists growers in assessing the risk to their individual operations regarding growth of specific clones or cultivars and sensitivity to diseases. By understanding these risks, seed growers have become more knowledgeable about their crop and have seen profits rise. A large portion of the seed crop is used locally by the commercial industry (21,000 mt/year) helping the overall Colorado potato industry maintain their commercial edge by having access to less expensive seed. Additionally, at an average price of $198/mt for certified seed and an output of 24.7 mt/ha usuable as seed, this represents approximately $13.7 million in sales generated by Colorado developed cultivars. Additionally, protected cultivars generated over $200,000 in royalty revenues to support Colorado State University research programs. |
| 2004 | Colorado's certified seed potato program recorded a total of 2771 ha of Colorado developed cultivars or clones representing 55% of the seed acreage accepted in 2004. Again, yields were excellent with the crop demonstrating relatively low levels of disease. This project assists growers in assessing the risk to their individual operations regarding growth of specific clones or cultivars and sensitivity to diseases. By understanding these risks, seed growers have become more knowledgeable about their crop and have seen profits rise. A large portion of the seed crop is used locally by the commercial industry (22,000+ mt/year) helping the overall Colorado potato industry maintain their commercial edge by having access to less expensive seed. Additionally, at an average price of $198/mt for certified seed and an output of 25.8 mt/ha usuable as seed, this represents approximately $13.7 million in sales generated by Colorado developed cultivars. Additionally, protected cultivars generated over $220,000 in royalty revenues to support Colorado State University research programs. |
| 2005 | Colorado's certified seed potato program accepted a total of 2908 ha of Colorado developed cultivars or clones as certified seed in 2005 representing 56% of the crop. Yields were excellent with the crop demonstrating relatively low levels of disease. Of note is the fact that the releases in the last three years have consistently shown sustainable low levels of disease in an environment where certain diseases like PVY has become increasingly difficult to control. This project has assisted growers in understanding the disease risks involved in producing certain cultivars and demonstrated methods to manage potential problems. Since a very large portion of the seed crop is utilized locally (in excess of 21,000 mt/year), cultivars with reduced disease issues have helped the overall commercial industry in Colorado remain competitive. Overall yields in 2005 in the San Luis Valley exceeded 42 mt/ha. The portion of the commercial crop utilizing direct planting of Colorado certified seed accounted for 350,000 mt of production in the San Luis Valley at an average price of $190/mt or approximately $60 million in gross revenues after accounting for shrink and cullage. A large portion of these revenues were generated by Colorado developed cultivars helping to fuel a successful commercial industry. Additional planting of year out or older seed of Colorado developed cultivars occurs, but is difficult to measure. Cultivars under Federal PVP developed by CSU generated over $190,000 in royalty revenues to support CSU research programs. |
| 2006 | Colorado's certified seed potato industry recorded an average of around 2500 ha of Colorado developed cultivars representing around 50% of the annual production. Yields of the newest Colorado developed cultivars have exceeded the standard cultivars produced in the San Luis Valley by 6 to 11 mt/ha annually. This has resulted in generating more revenue for the producer. CSU derived cultivars account for approximately $10-12 million annually to the seed producers. These cultivars have also helped generate royalties to support the potato research effort in Colorado in excess of $200,000 yearly. |
| Publications | |
| 2001 |
Davidson, R.D. and R.T. Zink. 2001. 2001 Research Report for Extension Potato Disease Control Project. Submitted to the San Luis Valley Research Center Committee. 31 pages. |
| 2002 |
Zink, R.T, R.D. Davidson, and A. Houser. 2002. 2002 Research Report for the Potato Disease Management project. Submitted to the San Luis Valley Research Center Committee. 58 pp. |
| 2003 |
Zink, R.T., Davidson,R. D. and Houser, A. 2003. 2003 Research Report for the Potato Disease Management Project. Submitted to the San Luis Valley Research Center Committee. 60 pp. |
| 2004 |
Zink, R.T., Davidson, R.D. and Houser, A. 2004. 2004 Research Report for the Potato Disease Management Project. Submitted to the San Luis Valley Research Center Committee. 68 pp. (unpub .) |
| 2005 |
Davidson, R.D., Zink, R.T., and Houser, A. 2005. Reports for the CPAC Research Committee; Potato Disease Control Project. 65 pages. Essah, S.Y.C., Holm, D.G., and Davidson, R.D. 2005. Timing vine kill to manipulate yield, tuber size distribution and quality of two red potatoes. In Annual Meetings Abstract. P22. http://www.umaine.edu/paa/ Whitworth, J.L., Nolte, P., McIntosh, C., and Davidson, R. 2005. Effect of Potato Virus Y on yield of three potato cultivars grown under different nitrogen levels. Plant Disease 90:73-76. |
| 2006 |
Davidson, R.D., R.T. Zink and A. Houser. 2005. Comprehensive Potato Research Progress Report for 2005. CPAC Research Subcommittee. 52 pp. |