Hairy Nightshade (Solanum sarrachoides) Competition with Two Potato Varieties

Weed Science ◽  
2011 ◽  
Vol 59 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Pamela J. S. Hutchinson ◽  
Brent R. Beutler ◽  
JaNan Farr

Greenhouse and field trials were conducted at the Aberdeen Research and Extension Center to determine the effect of hairy nightshade competition on two potato varieties with different growth habits. Greenhouse replacement trials included treatments of three plants total in each pot with potato : hairy nightshade ratios of 3 : 0, 2 : 1, 1 : 2, or 0 : 3. Varieties tested were ‘Russet Burbank’ and ‘Russet Norkotah’. Greenhouse-grown hairy nightshade (cotyledon to one-leaf stage) were transplanted into pots earlier than or at the same time as potato plant emergence. As the number of Russet Burbank plants per pot decreased, potato plant biomass dry weight (average per plant) increased, regardless of hairy nightshade number or transplant time. When hairy nightshade were transplanted before Russet Norkotah emergence, potato plant biomass dry weight per plant was similar, regardless of potato : nightshade ratio. Field trials were conducted with Russet Burbank and Russet Norkotah in 2004 and 2005. At potato emergence, greenhouse-grown hairy nightshade plants (one- to two-leaf) were transplanted in between potato rows at densities of 0, 1, 2, or 3 plants m−1row, and solid-seeded at approximately 100 plants m−1row. Hairy nightshade biomass, stem and berry number, and seeds per berry were reduced by competition from Russet Burbank due to the amount and duration of shading, as compared with Russet Norkotah. Russet Burbank U.S. No. 1 and total tuber yields in plots with 1 hairy nightshade plant m−1row were similar to weed-free control yields, whereas yields in plots with 2, 3, or 100 m−1row were reduced in comparison. In contrast, Russet Norkotah yields were reduced when only 1 hairy nightshade plant m−1row was present. Overall, Russet Norkotah were less competitive with hairy nightshade than Russet Burbank in both the greenhouse replacement and field trials.

Plant Disease ◽  
2017 ◽  
Vol 101 (10) ◽  
pp. 1812-1818 ◽  
Author(s):  
Shaonpius Mondal ◽  
Erik J. Wenninger ◽  
Pamela J.S. Hutchinson ◽  
Jonathan L. Whitworth ◽  
Deepak Shrestha ◽  
...  

Potato leaf roll virus (PLRV) can reduce tuber yield and quality in potato. Green peach aphid (Myzus persicae [Sulzer]) and potato aphid (Macrosiphum euphorbiae [Thomas]) are the two most important potato-colonizing PLRV vectors in the Pacific Northwest. We compared My. persicae and Ma. euphorbiae densities and PLRV incidences among potato varieties in the field to clarify the relationships between aphid abundance and PLRV incidence in plants. Aphids were sampled weekly over three years in the potato varieties Russet Burbank, Ranger Russet, and Russet Norkotah in a replicated field trial. In all years, My. persicae was more abundant than Ma. euphorbiae, representing at least 97% of samples. My. persicae densities did not differ among potato varieties across years; very low numbers of Ma. euphorbiae precluded such statistical comparisons for this species. PLRV infection did not differ significantly among potato varieties, although the percent of PLRV-infected plants differed among years when all varieties were combined (46% in 2013, 29% in 2011, 13% in 2012). For Ranger Russet and Russet Norkotah, PLRV incidence was positively correlated with aphid abundance as well as proportion of PLRV-positive aphids. In Russet Burbank, only aphid abundance was positively correlated with PLRV infection. Our results suggest that the three most commonly grown potato varieties in our region do not differ in their susceptibility to PLRV infection, and that aphid density was a consistent indicator of the risk of infection by this virus across varieties. Both of these findings can be used to hone PLRV monitoring and modeling efforts.


2006 ◽  
Vol 20 (4) ◽  
pp. 1023-1029 ◽  
Author(s):  
Pamela J.S. Hutchinson ◽  
Brent R. Beutler ◽  
Daniel M. Hancock

Sulfentrazone was applied POST at 13, 26, or 53 g ai/ha alone or in combination with metribuzin at 280 or 420 g ai/ha in field trials conducted with ‘Russet Burbank’ potatoes in 2002 to 2004. Sulfentrazone alone provided less than 84% redroot pigweed, common lambsquarters, and kochia control, although control usually improved to 90% or greater when metribuzin was included. Hairy nightshade control reached 90% only when the highest rates of both herbicides were applied in combination. Sulfentrazone alone did not provide any volunteer oat control, whereas control was 85% when the highest metribuzin rate was included. Potato crop injury, consisting of chlorosis, interveinal blackening of the leaves, eventual necrosis, leaf malformation, and plant stunting, increased as the sulfentrazone rate increased. In contrast, injury decreased as metribuzin rate increased from 0 to 420 g/ha, when averaged across sulfentrazone rates. Reduction in injury levels and increased weed control translated to improved tuber yields as metribuzin rate increased. However, when sulfentrazone was combined with the highest metribuzin rate, potato injury was still relatively high at 26 and 18% at 1 and 4 wk after treatment, and acceptance of sulfentrazone applied POST with metribuzin by potato growers is unlikely.


2014 ◽  
Vol 28 (3) ◽  
pp. 543-551 ◽  
Author(s):  
Pamela J. S. Hutchinson

Field research trials were conducted in Idaho at the Aberdeen Research and Extension Center in 2006 and 2007 to determine the critical interference period of hairy nightshade in potatoes. ‘Russet Norkotah’ variety was planted both years in plots three rows wide by 12 m long. When the potatoes had emerged, one- to two-leaf hairy nightshade plants that had been germinated and grown in the greenhouse were transplanted at a 2 m−1row density and allowed to grow for 10, 20, 30, or 40 d after emergence (DAE) before removal, or the potatoes were maintained weed-free for 0, 10, 20, 30, or 40 DAE before transplanting. Potatoes were harvested from the center row at the end of each growing season and yield and grade was determined. Russet Norkotah is a small-canopied potato variety and often does not completely close canopy in Idaho. Russet Norkotah U.S. No. 1 and total tuber yield were similar to weed-free yield when hairy nightshade transplanting was delayed up to 22 or 24 DAE, respectively, or planted at emergence and allowed to remain for only 6 or 11 d, respectively. Otherwise, yield decrease was 5% or greater. Therefore, the critical weed-free period for Russet Norkotah potato U.S. No. 1 or total tuber yields was 6 to 22 or 11 to 24 DAE, respectively.


2019 ◽  
pp. 61-67

Recognition of high yielding and nitrogen (N) fixing groundnut genotypes and desegregating them in the cereal-based cropping systems common in savannah regions will enhance food security and reduce the need for high N fertilizers hence, minimize the high cost and associated environmental consequences. Field trials were conducted during the 2015 growing season at the Research Farms of Bayero University Kano (BUK) and Institute for Agricultural Research (IAR), Ahmadu Bello University, Samaru-Zaria to assess the yield potential and Biolog- ical N fixation in 15 groundnut genotypes (ICG 4729, ICGV-IS 07823, ICGV-IS 07893, ICGV-IS 07908, ICGV- SM 07539, ICGV- SM 07599, ICGV-IS 09926, ICGV-IS 09932, ICGV-IS 09992, ICGV-IS 09994, SAMNUT-21, SAMNUT-22, SAMNUT-25, KAMPALA and KWANKWAS). The groundnut genotypes and reference Maize crop (SAMMAZ 29) were planted in a randomized complete block design in three replications. N difference method was used to estimate the amount of N fixed. The parameters determined were the number of nodules, nod- ule dry weight, shoot and root dry weights, pod, and haulm yield as well as N fixation. The nodule dry weight, BNF, haulm, and pod yield were statistically significant (P<0.01) concerning genotype and location. Similarly, their interac- tion effect was also highly significant. ICGV-IS 09926 recorded the highest nod- ule dry weight of 2.07mg /plant across the locations while ICGV-IS 09932 had the highest BNF value of 140.27Kg/ha. Additionally, KAMPALA had the high- est haulm yield, while ICGV-IS 07893 had the highest pod yield across the loca- tions with a significant interaction effect. The result shows that ICGV-IS 07893 and ICGV-IS 09932, as well as ICGV-IS 09994 and SAMNUT – 22, were the best genotypes concerning BNF, haulm and pod yield in the Northern Guinea and Sudan Savannahs of Nigeria respectively with the potential for a corresponding beneficial effect.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 485b-485
Author(s):  
Lisa M. Barry ◽  
Michael N. Dana

Nurse crops are often recommended in prairie restoration planting. This work investigated several alternative nurse crops to determine their utility in prairie planting. Nurse crops were composed of increasing densities (900, 1800, or 2700 seeds/m2) of partridge pea, spring oats, spring barley, Canada wild rye, or equal mixtures of partridge pea and one of the grasses. The experimental design was a randomized complete-block set in two sites with three blocks per site and 48 treatments per block. Each 3 × 3-m plot contained 1 m2 planted in Dec. 1995 or Mar. 1996 with an equal mix of seven prairie species. The nurse crops were sown over each nine square meter area in April 1996. Plots lacking nurse crops served as controls. Evaluated data consisted of weed pressure rankings and weed and prairie plant dry weight. Nurse crop treatments had a significant effect on weed pressure in both sites. Barley (1800 and 2700 seeds/m2) as well as partridge pea + barley (2700 seeds/m2) were most effective at reducing weed pressure. When weed and prairie plant biomass values were compared, a significant difference was observed for site quality and planting season. Prairie plant establishment was significantly greater in the poorly drained, less-fertile site and spring-sown plots in both sites had significantly higher prairie biomass values. Overall, after two seasons, there was no advantage in using nurse crops over the control. Among nurse crop treatments, oats were most effective in reducing weed competition and enhancing prairie plant growth.


Plant Disease ◽  
2007 ◽  
Vol 91 (10) ◽  
pp. 1305-1309 ◽  
Author(s):  
Khalil I. Al-Mughrabi ◽  
Rick D. Peters ◽  
H. W. (Bud) Platt ◽  
Gilles Moreau ◽  
Appanna Vikram ◽  
...  

The efficacy of metalaxyl-m (Ridomil Gold 480EC) and phosphite (Phostrol) applied at planting in-furrow against pink rot (Phytophthora erythroseptica) of potato (Solanum tuberosum) ‘Shepody’ and ‘Russet Burbank’ was evaluated in field trials conducted in 2005 and 2006 in Florenceville, New Brunswick, Canada. Inoculum made from a metalaxyl-m-sensitive isolate of P. erythroseptica from New Brunswick was applied either in-furrow as a vermiculite slurry at planting or as a zoospore drench in soils adjacent to potato plants in late August. After harvest, the number and weight of tubers showing pink rot symptoms were assessed and expressed as percentages of the total tuber number and total weight of tubers. Metalaxyl-m applied in-furrow was significantly more effective against pink rot than phosphite. The mean percentage of diseased tubers as a percentage of total tuber weight was 1.5% (2005) and 1.2% (2006) for metalaxyl-m-treated plots and 9.6% (2005) and 2.8% (2006) for phosphite-treated plots, a percentage similar to that obtained in inoculated control plots with no fungicide treatment. The mean percentage of diseased tubers expressed as a percentage of the total number of tubers was 1.7% (2005) and 1.3% (2006) for metalaxyl-m-treated plots and 10.1% (2005) and 3.1% (2006) for phosphite-treated plots. Disease incidence was significantly higher using the late-season inoculation technique (respective means in 2005 and 2006 were 9.9 and 3.8% diseased tubers, by weight, and 10.6 and 3.9%, by number) than with the in-furrow inoculation method (respective means in 2005 and 2006 were 3.3 and 0.7% by weight, and 3.7 and 1.3%, by number). The potato cv. Shepody was significantly more susceptible to pink rot (9.9 and 3.3% diseased tubers, by weight, in 2005 and 2006, respectively, and 10.6 and 3.9%, by number) than Russet Burbank (respective means in 2005 and 2006 were 3.4,% and 1.2%, by weight, and 3.7,% and 1.2%, by number). Our findings indicate that metalaxyl applied in-furrow at planting is a viable option for control of pink rot caused by metalaxyl-sensitive strains of P. erythroseptica, whereas phosphite was ineffective.


2020 ◽  
Vol 27 (2) ◽  
pp. 507-523
Author(s):  
Amir Ehsan ◽  
Muhammad Ehsan Safdar1 ◽  
Amjed Ali

ABSTRACT There is little understanding about ecological interference of weeds in direct-seeded rice. To get estimates of economic thresholds of two weeds in direct seeded rice, two-year field trials were conducted at research area of College of Agriculture, University of Sargodha, Punjab-Pakistan. Treatments included 0, 22, 44, 66 and 88 plants m-2 densities of each of Echinochloa colona and Digera arvensis laid out in randomized complete block design. Augmented densities of E. colona (0, 22, 44, 66 and 88 weed plants m-2) enhanced its plant dry biomass up to 348 and 353%; and relative competitive index maximally to 80 and 77% in years 2015 and 2016, respectively. While the corresponding increases in plant dry weight and relative competitive index of D. arvensis were 367 and 360% and 79 and 82%. The enhancement in N (up to 258 & 257 %), P (up to 220 & 232%) and K (up to 293 & 301%) uptake in years 2015 and 2016, respectively were made by E. Colona whereas the corresponding increases in N, P and K assimilation by D. arvensis were as far as 265 & 257%, 238 & 233% and 305 & 298%, respectively. The declines in growth and yield of rice were observed in response to growing number of both the weeds. Rice grain yield losses ranged between 9.8 to 80% and 28 to 80% by E. Colona and D. arvensis. The economic thresholds of false amaranth and jungle rice were estimated to be 1.6-1.4 plants m-2 and 2.2-2.6 plants m-2, respectively.


HortScience ◽  
2017 ◽  
Vol 52 (5) ◽  
pp. 764-769 ◽  
Author(s):  
Qiang Zhu ◽  
Monica Ozores-Hampton ◽  
Yuncong Li ◽  
Kelly Morgan ◽  
Guodong Liu ◽  
...  

Florida produces the most vegetables in the United States during the winter season with favorable weather conditions. However, vegetables grown on calcareous soils in Florida have no potassium (K) fertilizer recommendation. The objective of this study was to evaluate the effects of K rates on leaf tissue K concentration (LTKC), plant biomass, fruit yield, and postharvest quality of tomatoes (Solanum lycopersicum L.) grown on a calcareous soil. The experiment was conducted during the winter seasons of 2014 and 2015 in Homestead, FL. Potassium fertilizers were applied at rates of 0, 56, 93, 149, 186, and 223 kg·ha−1 of K and divided into preplant dry fertilizer and fertigation during the season. No deficiency of LTKC was found at 30 days after transplanting (DAT) in both years. Potassium rates lower than 149 kg·ha−1 resulted in deficient LTKC at 95 DAT in 2014. No significant responses to K rates were observed in plant (leaf, stem, and root combined) dry weight biomass at all the sampling dates in both years. However, at 95 DAT, fruit dry weight biomass increased with increasing K rates to 130 and 147 kg·ha−1, reaching a plateau thereafter indicated by the linear-plateau models in 2014 and 2015, respectively. Predicted from quadratic and linear-plateau models, K rates of 173 and 178 kg·ha−1 were considered as the optimum rates for total season marketable yields in 2014 and 2015, respectively. Postharvest qualities, including fruit firmness, pH, and total soluble solids (TSS) content, were not significantly affected by K rates in both years. Overall, K rate of 178 kg·ha−1 was sufficient to grow tomato during the winter season in calcareous soils with 78 to 82 mg·kg−1 of ammonium bicarbonate-diethylenetriaminepentaacetic acid (AB-DTPA)-extracted K in Florida.


2019 ◽  
Vol 50 (3) ◽  
pp. 155-163 ◽  
Author(s):  
B. Talebi ◽  
M. Heidari ◽  
H. Ghorbani

Abstract The elevation of arsenic (As) content in soils is of considerable concern with respect to its uptake by plant and subsequent entry into wildlife and human food chains. The treatment of sorghum seedlings with As as NaH2As4O. 7H2O at various concentrations (A1 = 0, A2 = 20, A3 = 40 and A4 = 60 mg As kg−1 soil) and salinity at four different levels (S1 = 0, S2 = 3, S3 = 6 and S3 = 9 dS m−1) reduced fresh and dry weights of sorghum plants. The co-application of As and salinity increased the guaiacol peroxidase (GPX) activity in shoot and root tissues. The highest GPX activity in shoot and root tissues was obtained at S2A4 and S3A3 treatments, respectively. The activity of catalase (CAT) in shoot was not changed, but unlike the GPX activity, salinity and As decreased the CAT activity in root tissues. Concerning the photosynthesis pigments, salinity had no effect on the chlorophyll ‘a’, chlorophyll ‘b’ and carotenoid content in leaves, but the As treatment significantly decreased the content of both chlorophyll types. Salinity increased the anthocyanin content in leaves. There were negative correlation between soluble carbohydrates (r2 = −0.78**) and stomata conductance (r2 = −0.45**) and dry weight of the plant biomass in this study. By increasing the salinity and As concentration in root medium, soluble carbohydrate in leaves increased but salinity decreased the leaf stomata conductance.


1991 ◽  
Vol 116 (2) ◽  
pp. 191-200 ◽  
Author(s):  
E. M. White

SUMMARYApplications of nitrogen and a plant growth regulator (mepiquat chloride and ethephon) were used to manipulate stem structure and induce differing degrees of damage due to leaning and lodging in six cultivars of winter barley grown in Belfast, UK, in 1986/87. Weighted incidences of leaning and lodging were combined to give an index indicating damage susceptibility of the cultivars. The index was very high (70) in Pipkin and ranged between 1 and 18 in the other cultivars. Differences between cultivars in number of internodes, plant height and stem weight did not explain their differences in resistance to damage. However, dry weight per unit length ranged from 2·35 and 2·34 mg/mm in the strongest cultivars, Panda and Jennifer, respectively, to 1·75 mg/mm in the weakest cultivar, Pipkin.Nitrogen application increased plant height but did not affect dry weight/main stem, so that dry weight/unit length of stem decreased. The growth regulator treatments reduced plant height and although dry weight/stem did not decrease significantly, dry weight/unit length of stem was similar in treated and untreated plots.Dry weight/unit length has potential as an objective indicator of straw strength in winter barley cultivars and could be used in cultivar evaluation in the absence of damage in field trials.


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