Progress 01/01/05 to 12/31/05
Outputs
Rye cover crop mulch suppressed both eastern black nightshade and tomato growth and berry production. It also increased soil bulk density, decreased soil temperatures, and increased soil moisture content. All three soil characteristics have been linked to reduced and delayed yields in both tomatoes and other commercial crops. In the rye cover crop mulch, staking increased light interception only in the middle of the tomato canopy, and canopy density studies found staking to decrease total overhead canopy. Staking concentrates tomato and nightshade canopy on a vertical plane, elevating both the tomato and nightshade off of the ground, but offers no consistent advantage for tomato plants to access light. Overall, staking is inconsistent for elevating tomatoes over competing nightshade plants, and inconsistent in giving tomatoes an advantage in obtaining light. Rye cover crop mulch severely inhibited tomato yield, tomato and nightshade free-standing height, tomato and
nightshade vine length, and tomato and nightshade dry leaf biomass. Although the rye increased the percentage of marketable (USDA Grade A) tomatoes, the reduction in tomato growth and yield is a disadvantage for using rye cover cropping with heavy soils.
Impacts
If problems with alternative methods, cereal rye cover crop mulch and staking can be overcome then the need for herbicides, tillage, and hand-weeding will be reduced. Reductions in current weed management practices will save vegetable farmers a large input cost (hand-weeding), reduce soil erosion, and lessen surface and ground water pollution.
Publications
- Bicksler, A. 2005. The biology of weedy nightshade species. MS Thesis, University of Illinois at Urbana-Champaign.
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Progress 09/15/01 to 09/14/05
Outputs
Solanaceous plants such as eastern black nightshade are problem weeds. Our research objectives were to understand the interrelationships between nightshades and to develop strategies for managing the weeds. Eastern black nightshade, black nightshade, and American black nightshade were more genetically similar to each other than to other solanaceous species while bitter nightshade and groundcherry were distinct from other species. Accessions of black nightshade, American black nightshade, horsenettle, hairy nightshade, and bitter nightshade each separated into distinct clusters. All but three of the twenty-five accessions of eastern black nightshade were in a single cluster. Apple of Peru and eastern black nightshade were taller than clammy groundcherry, smooth groundcherry, and horsenettle. The days to flowering of Apple of Peru and was reduced in the 10/14 hr photoperiod while horsenettle, smooth and clammy nightshade did not flower. The plants were larger in the
14/10 than 10/14 hr photoperiod. Seed viability increased with berry size and with length of establishment or removal time. The critical weed-free period to avoid viable nightshade seed production was 3 to 6 weeks after planting. Tomato yield decreased with early weed establishment or with delayed time of weed removal. The critical weed-free period to avoid greater than 20% loss for premium fruit grades was 28 to 50 d. The value of the sum of large, extra large, and jumbo grades was reduced by 1 eastern black nightshade plant per hole. Tomatoes did not consistently overtop nightshade and staking did not improve tomato competition for light. In 2003, nightshade interference and rye cover crop mulch decreased total tomato yield. In 2004, nightshade interference did not affect tomato yield, but rye cover crop decreased total yield. In 2004, rye treatments increased soil bulk density, decreased soil temperatures, and increased soil moisture content. Eastern black nightshade was more
tolerant to metribuzin and halosulfuron than hairy nightshade, horsenettle, clammy groundcherry, and smooth groundcherry. Hairy nightshade was more susceptible and clammy nightshade was more tolerant to sulfentrazone than other solanaceous species. Horsenettle was the most susceptible species to sulfosulfuron. Pydridate controlled all solanaceous species tested except smooth groundcherry. The Ingham2 eastern black nightshade accession was more tolerant to sulfentrazone, metribuzin, and halosulfuron while Macomb3 was more susceptible to halosulfuron than other eastern black nightshade accessions. The Oceana1 eastern black nightshade accession was more tolerant to sulfosulfuron while Monroe4 was less tolerant to metribuzin than other accessions. Bay2 and Macomb1 hairy nightshade accessions were more tolerant to halosulfuron than other accessions. Our research indicates that eastern black nightshade accessions are closely related. One eastern black nightshade per crop hole reduces tomato
yield. Rye cover crop mulch is nonselective reducing both nightshade and tomato growth and reproduction. Herbicide effectiveness varies depending on solanaceous species and accession.
Impacts
Most eastern black nightshade plants are gentically similar but still differ in susceptibility to herbicides. Nightshade competitiveness with tomato is similar throughout the eastern U.S. Improved eastern black nightshade management will depend on understanding susceptibility of accessions to new environmentally-friendly herbicides and overcoming the limitations of alternative systems. Better nightshade management systems will save farmers inputs (hand-weeding, tillage, and high-use rate herbicides), reduce soil erosion, and lessen soil and ground water pollution. Improved nightshade management in tomato will allow farmers to provide a quality and economical tomato crop to meet consumer demand for locally-grown produce.
Publications
- Buckelew, J.K. and Monks, D.W. 2006. Effect of astern black nightshade (Solanum ptycanthum) on transplanted plasticulture tomato grade and yield. Weed Sci. 54:504508.
- Buckelew, J.K., Monks, D.W., Jennings, K.M., Hoyt G.D. and Walls, Jr., R.F. 2006. Eastern black nightshade (Solanum ptycanthum) reproduction and interference in transplanted plasticulture tomato. Weed Sci. 54:490-495.
- Kamboj, A., Doohan D. and Felix, J. 2006. Differential effects of photoperiod on development of solanaceous weed species. North Central Weed Science Society Proceedings 61:84.
- Pandian, V. 2005. Evaluation of nightshade (Solanum spp.) and groundcherry species (Physalis spp.) response to herbicides. MS. Thesis. Michigan State University. East Lansing, MI. 146 p.
- Pandian, V. and Zandstra, B.H. 2004. Difference in herbicide response among nightshade and groundcherry species in Michigan. North Central Weed Science Society Proceedings 59:50.
- Pandian, V. and Zandstra, B. H. 2004. Difference in herbicide response among eastern black nightshade and hairy nightshade populations in Michigan. North Central Weed Science Society Proceedings 59:91.
- Sharkhuu, A., Goldsbrough, P.B. and Weller, S.C. 2004. RAPD analysis on genetic diversity of nightshade species in the North Central Region. North Central Weed Science Society Proceedings 59:58.
- Uhlig, R.E. and Zandstra, B.H. 2006. Stimulation of germination of eastern black nightshade, smooth groundcherry, and clammy groundcherry seeds with sulfonylurea herbicides. North Central Weed Science Society Proceedings 61:174.
- Bicksler, A. 2005. Effects of rye cover crop and staking on eastern black nightshade interference in processing tomatoes. M.S. Thesis. University of Illinois. Urbana, IL.
- Bicksler, A.J. and Masiunas, J.B. 2004. The effects of cultural practices on nightshade competition with processing tomatoes. North Central Weed Science Society Proceedings 59:96.
- Bucklew, J. 2005. Eastern black nightshade management in plasticulture tomatoes. M.S. Thesis. Department of Horticulture. North Carolina State University. Raleigh, NC.
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Progress 01/01/04 to 12/31/04
Outputs
Studies continued at Illinois, Michigan, Indiana, Ohio, and North Carolina. There were no differences in tomato yield caused by having 1-5 nightshade per planting hole, except for weight of jumbo (premium) grade fruit which decreased above one nightshade per hole with asymptotic yield loss reaching 84%. Large eastern nightshade berries, >9 mm diameter, showed 100% viability, 6.3 - 9 showed 49%, 5 - 6.3 showed 9%, and 3 - 5 showed 0.4%. Eastern black nightshade seedlings established before 2 weeks after transplanting or removed after 6 weeks after transplanting resulted in the majority of viable seed production. Eastern black nightshade, S. ptycanthum, germination was increased by treatments of potassium nitrate and gibberellic acid. In 2003, rye cover cropping reduced nightshade growth and tomato yield. In 2004, nightshade did not affect tomato yield, but rye decreased total yield. Grade A tomatoes were greatest and culls were lowest in the rye cover crop. In both
years, staking increased tomato height, but did not consistently elevate tomato plants above nightshade plants. The Ingham2 eastern black nightshade population had more tolerance than other populations to sulfentrazone, metribuzin and halosulfuron. The Macomb3 population had more susceptibility to halosulfuron (GR50= 0.01 kg/ha) than other populations. The Oceana1 population had a higher tolerance to sulfosulfuron than the other populations. A wide range of tolerance to metribuzin was observed with the Monroe4 population, the least tolerant (GR50=0.28 kg/ha). There was a wide range of variation to halosulfuron among five populations of hairy nightshade with Bay2 and Macomb1 more tolerant than others. Research was conducted to study the genetic diversity of eastern black nightshade compared to horsenettle, American black nightshade and bitter nightshade, clammy groundcherry and smooth groundcherry using Random Amplification of Polymorphic DNA analysis. The group of eastern black
nightshade plants was divided into 11 subgroups by cluster analysis. All accessions within a species had a similarity coefficient >0.75. The genetic relationships developed indicated that eastern black nightshade, black nightshade and American black nightshade species were more genetically similar to each other than to other solanaceous species while bitter nightshade and ground cherry species were distinct. Among the eastern black nightshade accessions studied, all but three were in the same cluster. Accessions of black nightshade, American black nightshade, horsenettle, hairy nightshade and bitter nightshade species were each separated into distinct clusters except for two accessions that through RAPD analysis were identified as American black nightshade and eastern black nightshade.
Impacts
Nightshade variation in appearance makes identification and control more difficult. An improved understanding of this variation will help in targeting mananagement practices. Staking and low-risk herbicides will provide environmentally-friendly control methods.
Publications
- No publications reported this period
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Progress 01/01/03 to 12/31/03
Outputs
The black nightshade complex (Solanum Sect. Solanum) includes troublesome weeds in horticultural crops. The black nightshade complex is difficult to classify because of extensive morphologic variation. Seeds of more than two hundred samples belonging to six nightshade and three groundcherry species were collected throughout the Midwestern U.S. In eastern black nightshade we found variation in life cycle, plant size, growth habit, flower size, berry color at maturity, growth rate, and berry production. RAPD molecular marker analysis determined the degree of genetic variation occurring within and between these species. The genetic relationships indicate: black nightshade and American nightshade are more genetically similar to each other than to other nightshade species; eastern black nightshade separated into 2 closely related groups as did hairy nightshade; horsenettle separated into 3 distinct groups; and bitter nightshade and groundcherry groupings were distinct from
each other and from all nightshade species. Temperature and photoperiod influence plant development. All plants were smallest in a 10/14 hour light/dark regime; with horsenettle and clammy groundcherry not flowering even after 120 days. Under a 10/14 hour regime, apple of Peru initiated flower buds 15 days after emergence (DAE) and eastern black nightshade initiated flower buds 17 DAE. When exposed to 14/10 and 16/8 hours, apple of Peru and eastern black nightshade flowered 31 DAE compared to 60 days for the groundcherries. Horsenettle flowered 97 DAE under 14/10 and 16/8 hour regimes. Results suggest that apple of Peru and eastern black nightshade germinating in late summer or in crop-shaded canopies can produce seeds. Cropping practices may increase tomato competitiveness with nightshade. We evaluated a rye cover crop and staking as techniques to increase the competitiveness of tomatoes with nightshade. The rye cover crop inhibited tomato and nightshade growth. The growth and yield
inhibition was due to soil compaction. Staking raised the tomato canopy over the nightshade and made the tomatoes more competitive for light. Two studies were conducted to determine the critical weed-free period and critical density for eastern black nightshade in a tomato plasticulture system. Densities of 1, 2 or 3 nightshade plants per crop plant reduced yield compared to the weed free check. Eastern black nightshade regrew from roots of plants that were clipped at the ground or from overwintering root systems. Shoots re-established after clipping. Low risk herbicides were evaluated to control eastern black nightshade in tomatoes. In pre-transplant applications, oxyfluorfen (0.28 kg/ha), sulfentrazone (0.34 kg/ha), and flumioxazin (0.05 kg/ha) gave at least 95% control of nightshade, with no crop injury. In post-transplant applications, dimethenamid (1.1. kg/ha) and s-metolachlor (1.8 kg/ha) gave 100% nightshade control with no crop injury. In postemergence applications,
sulfentrazone controlled nightshade 60 to 93% but caused 30% reduction in tomato yields. Sulfosulfuron, rimsulfuron, and halosulfuron did not control nightshade. Carfentrazone substantially injured tomatoes.
Impacts
Nightshade variation in appearance makes identification and control more difficult. An improved understanding of this variation will help in targeting mananagement practices. Staking and low-risk herbicides will provide environmentally-friendly control methods.
Publications
- Wahle, E.A. and Masiunas, J.B. 2003. Comparison of nitrogen use by two population densities of eastern black nightshade. Weed Science 51:394-401.
- Wahle, E.A. and Masiunas, J.B. 2003. Competition for nitrogen between eastern black nightshade and fresh market tomato. Weed Science 51:725-731.
- Wahle, E.A. and Masiunas, J.B. 2003. Nitrogen fertilizer and population density affect tomato growth and yield. HortScience 37:367-372.
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Progress 01/01/02 to 12/31/02
Outputs
Eastern black nightshade (Solanum ptycanthum) is a problem weed in many vegetable crops, especially tomatoes. Groundcherries are a related genera in the same family, which although occurring throughout eastern North America are not a problem weed. Our objective was to determine the characteristics which make eastern black nigtshade a problem weed and to develop environmentally-friendly strategies to manage nightshade in tomatoes. Eastern black nightshade, horsenettle, clammy and common groundcherry were collected from throughout Michigan, Indiana, Illinois, Ohio, and North Carolina. These accessions are being grow in the greenhouse and their morphology studied. Another study started to determine the genome for each accession. The impact of nitrogen fertilizer on the competitiveness of nightshade in tomato was studied. If differences in nitrogen needs exist, it might be possible to develop fertily programs that favor tomato growth over nightshade growth. Nitrogen
fertilizer increased growth of both nightshade and tomato. Applications of nitrogen fertilizer early in the growing season or directly to the tomatoes will increase its competitiveness with nightshade.
Impacts
An understanding of the factors that make eastern black nightshade a problem in tomatoes will allow us to target management strategies to susceptible stages of the weed's life cycle. The requirement of nightshade for high levels of nitrogen fertilizer will make it possible to favor tomato growth, reducing problems with nightshade and more efficiently using nitrogen fertilizer.
Publications
- Wahle, E. 2001. Competition between tomato and eastern black nightshade for nitrogen. Ph.D. Thesis. University of Illinois, Urbana.
- Wahle, E. A. and Masiunas, J. B. 2003. Comparison of nitrogen use by two population densities of eastern black nightshade. Weed Science 51 (In Press).
- Wahle, E. A. and Masiunas, J. B. 2003. Competition for nitrogen between eastern black nightshade and fresh market tomato. Weed Science 51 (In Press).
- Wahle, E.A. and Masiunas, J.B. 2003. Nitrogen fertilizer and population density affect tomato growth and yield. HortScience 37 (In Press).
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Progress 01/01/01 to 12/31/01
Outputs
Eastern black nightshade is a severe problems in tomatoes grown east of the Rocky Mountains. It can not be controlled by standard preplant herbicides or through tillage. Groundcherries, although found throughout the same range are not a problem weed. Our research aims at understanding why these differences in weediness occur and to use that information to design alternative nightshade management systems for tomatoes. We are currently collecting seed of these weeds from Illinois, Indiana, Michigan, Ohio, and North Carolina. The seed is being isolated from the berries and planted in the greenhouse for seed increase and to study the morphology of the plants.
Impacts
Eastern black nightshade is a severe problems in tomatoes grown east of the Rocky Mountains. It can not be controlled by standard preplant herbicides or through tillage. Groundcherries, although found throughout the same range are not a problem weed. Our research aims at understanding why these differences in weediness occur and to use that information to design alternative nightshade management systems for tomatoes.
Publications
- No publications reported this period
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