scholarly journals Sphaeropsis sapinea and Water Stress in a Red Pine Plantation in Central Wisconsin

1997 ◽  
Vol 87 (4) ◽  
pp. 429-434 ◽  
Author(s):  
J. T. Blodgett ◽  
E. L. Kruger ◽  
G. R. Stanosz
Keyword(s):  
Water Stress ◽  
Severe Disease ◽  
Red Pine ◽  
Disease Development ◽  
Competing Vegetation ◽  
Inoculation Site ◽  
Lateral Shoots ◽  
Sphaeropsis Sapinea ◽  
Individual Trees ◽  
Water Treatments

A study was conducted to determine the effects of water stress resulting from competing vegetation on disease development of Sphaeropsis sapinea in red pine plantations. A 9-year-old plantation was selected in 1992 and experiments were conducted for three consecutive years. Four treatments were assigned at random to individual trees: no treatment, herbicide to kill surrounding weeds, supplemental water, and both herbicide and supplemental water. Two isolates of each S. sapinea morphotype (A and B) were used to inoculate wounded lateral shoots. Disease development was measured as the maximum distance below the inoculation site at which necrotic needles were observed. Nonwatered trees with competing vegetation (nontreated condition) had significantly lower predawn needle water potentials (more water stress) and more severe disease development than trees that received the herbicide, water, or combined herbicide and water treatments. The most severe disease occurred in the driest year and the least in the wettest year. Competing vegetation indirectly affected disease development by inducing water stress, even in relatively moist years, on trees previously considered well established. Isolates of morphotype A were more aggressive than isolates of morphotype B. Conclusions from this research have implications for sustainable management of the region's conifer forests.

Effects of Moderate Water Stress on Disease Development by Sphaeropsis sapinea on Red Pine

1997 ◽  
Vol 87 (4) ◽  
pp. 422-428 ◽  
Author(s):  
J. T. Blodgett ◽  
E. L. Kruger ◽  
G. R. Stanosz
Keyword(s):  
Water Stress ◽  
Pinus Resinosa ◽  
Greenhouse Experiment ◽  
Red Pine ◽  
Growth Chamber ◽  
Disease Development ◽  
Chamber Experiment ◽  
Inoculation Site ◽  
Shoot Blight ◽  
Sphaeropsis Sapinea

The aggressiveness of Sphaeropsis sapinea isolates was compared on water-stressed and nonstressed 3-year-old red pines (Pinus resinosa) in greenhouse and growth chamber experiments. Water was withheld from stressed seedlings to achieve mean predawn needle water potentials (ψPD) above −1.9 MPa. The lowest mean ψPD of well-watered seedlings was maintained at or above −0.8 MPa. Young shoots were inoculated by placing colonized agar plugs on wounds made by removing a needle fascicle. Two isolates of each recognized morphotype (A and B) were used in the greenhouse experiment and two isolates of morphotype A were used in the growth chamber experiment. After 4 weeks, isolates of morphotype A caused more severe symptoms and could be recovered farther from the inoculation site on water-stressed than on nonstressed trees in both experiments. In the greenhouse experiment, isolates of mor-photype A also caused more severe symptoms and could be recovered farther from the inoculation site than isolates of morphotype B, regardless of watering regime. These results indicate that water stress at levels observed typically in the field can result in increased disease development by isolates of S. sapinea morphotype A on red pine. The reduction of water stress of red pines in the field may reduce losses due to Sphaeropsis shoot blight.

scholarly journals Monoterpene and Phenolic Compound Concentrations in Water-Stressed Red Pine Inoculated with Sphaeropsis sapinea

1998 ◽  
Vol 88 (3) ◽  
pp. 245-251 ◽  
Author(s):  
J. T. Blodgett ◽  
G. R. Stanosz
Keyword(s):  
Water Stress ◽  
Phenolic Compounds ◽  
Field Experiment ◽  
Red Pine ◽  
Growth Chamber ◽  
Tissue Extracts ◽  
Pine Trees ◽  
Sphaeropsis Sapinea ◽  
Individual Trees

Changes in monoterpene and phenolic compounds resulting from water stress and colonization by Sphaeropsis sapinea were examined for 9- and 11-year-old red pine trees in a plantation and 3-year-old seedlings in a growth chamber. Four treatments were assigned at random to individual trees in the field: no treatment, herbicide to kill surrounding weeds, supplemental water, and both herbicide and supplemental water. In the growth chamber, seedlings were either not watered (water stressed) or watered daily (nonstressed). Shoots were inoculated with agar plugs colonized with either S. sapinea isolates of morphotype A and B (field) or only isolates of morphotype A (growth chamber). Nine monoterpenes were detected in tissue extracts; the most common were α-pinene (59 to 74% of the total), β-pinene (13 to 33% of the total), and δ-3-carene (1 to 5% of the total). Shoots inoculated with isolates of morphotype A had more severe symptoms and produced higher concentrations of monoterpenes in both experiments compared with the controls. In the growth chamber, inoculations with isolates of morphotype A caused higher concentrations of phenolics compared with the controls. In the field experiment, monoterpenes increased in quantity only in shoots of stressed trees inoculated with isolates of morphotype A. Isolates of morphotype B caused few symptoms and did not alter monoterpene concentrations. Increases in monoterpenes do not appear to be involved in the response to infection by morphotype A in nonstressed trees, and the role of phenolics is unclear. However, these results are consistent with previous observations that monoterpenes may be involved in the differences in aggressiveness between morphotypes on red pine.

scholarly journals Interaction Between Diplodia pinea and D. scrobiculata in Red and Jack Pine Seedlings

2011 ◽  
Vol 101 (3) ◽  
pp. 334-339 ◽  
Author(s):  
O. Santamaría ◽  
D. R. Smith ◽  
G. R. Stanosz
Keyword(s):  
Symptom Severity ◽  
Fungal Pathogen ◽  
Disease Development ◽  
Symptom Development ◽  
Diplodia Pinea ◽  
Inoculation Site ◽  
Pine Seedlings ◽  
Shoot Blight ◽  
Sphaeropsis Sapinea ◽  
Stem Cankers

Sphaeropsis sapinea sensu lato is a conifer fungal pathogen that causes shoot blight and stem cankers. Recently, the former S. sapinea has been divided into two species, Diplodia pinea and D. scrobiculata. The aims of the study were to determine the contribution of each species in disease development on red and jack pines by means of co-inoculations and molecular identifications, and to evaluate how the presence of each species affects the development and aggressiveness of the other. Symptom severity (distance below the inoculation site at which necrotic needles were observed) and identification length (the maximum distance from inoculation site from which either D. pinea or D. scrobiculata was identified using molecular methods) were recorded 4 weeks after inoculating wounded seedlings with agar plugs colonized by these pathogens. The results suggested that D. pinea was much more aggressive on both hosts than D. scrobiculata. When a seedling was co-inoculated with these pathogens, the symptom development appeared to be mainly due to D. pinea. The presence of D. pinea also interfered with the establishment of D. scrobiculata in the plant tissue. However, D. scrobiculata showed antagonism toward D. pinea. When both pathogens co-occurred in a single seedling, symptom severity caused by D. pinea was less than when D. pinea alone was present.

scholarly journals Water stress and Sphaeropsis sapinea as a latent pathogen of red pine seedlings

2001 ◽  
Vol 149 (3) ◽  
pp. 531-538 ◽  
Author(s):  
G. R. Stanosz ◽  
J. T. Blodgett ◽  
D. R. Smith ◽  
E. L. Kruger
Keyword(s):  
Water Stress ◽  
Red Pine ◽  
Pine Seedlings ◽  
Sphaeropsis Sapinea

scholarly journals Sphaeropsis sapinea Morphotypes Differ in Aggressiveness, but Both Infect Nonwounded Red or Jack Pines

Plant Disease ◽  
1997 ◽  
Vol 81 (2) ◽  
pp. 143-147 ◽  
Author(s):  
J. T. Blodgett ◽  
G. R. Stanosz
Keyword(s):  
Symptom Severity ◽  
Pinus Resinosa ◽  
Jack Pine ◽  
Red Pine ◽  
North Central ◽  
The North ◽  
Inoculation Site ◽  
Central United States ◽  
Sphaeropsis Sapinea ◽  
Natural Stands

Two morphotypes of Sphaeropsis sapinea, designated A and B, are recognized in the north central United States. Nonwounded seedlings of red (Pinus resinosa) and jack pine (P. banksiana) were inoculated with conidial suspensions of isolates of each morphotype obtained from hosts in Michigan, Minnesota, and Wisconsin. Wounded seedlings were inoculated with water agar plugs colonized by these isolates. Both morphotypes penetrated both hosts without wounding. On nonwounded seedlings the frequency of symptoms was 97% for A isolates and 18% for B isolates on red pine and 42% for A isolates and 6% for B isolates on jack pine. On average, isolates of the A morphotype also were more aggressive than B isolates on wounded seedlings of both pine species (A isolates causing needle necrosis 7.0 cm from the inoculation sites and B isolates 1.4 cm). Based on symptom severity (distance from the inoculation site at which necrotic needles were observed), A isolates could be distinguished from all B isolates on red pine, but not on jack pine. These observations indicate the potential importance of distinguishing between S. sapinea morphotypes encountered in nurseries, plantations, and natural stands.

scholarly journals High Phosphorus Acquisition and Allocation Strategy Is Associated with Soybean Seed Yield under Water- and P-Limited Conditions

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 574
Author(s):  
Yun-Yin Feng ◽  
Jin He ◽  
Yi Jin ◽  
Feng-Min Li
Keyword(s):  
Water Stress ◽  
Water Supply ◽  
Seed Yield ◽  
Soybean Seed ◽  
Dry Weight ◽  
Water Regimes ◽  
P Acquisition ◽  
Application Rates ◽  
Soybean Genotypes ◽  
Water Treatments

Both water stress and P deficit limit soybean seed yield, but the effects of water regimes and P application rates, their interaction on P status, acquisition, and partitioning, and their roles in yield performance have not been well-studied. Two soybean genotypes (Huangsedadou (HD) and Zhonghuang 30 (ZH)) with contrasting seed yield and root dry weight (DW) were used to investigate the P status, P acquisition, P partitioning, and yield formation under two water regimes (well-watered (WW) and cyclic water stress (WS)) and three P rates (0 (P0), 60 (P60), and 120 (P120) mg P kg−1 dry soil). The results show that increased P and water supply increased the seed yield, shoot and root DW and P concentrations and accumulations in different organs. Cultivar ZH had a significantly higher seed yield than HD at P60 and P120 under WS and at P0 under WW, but a lower seed yield at P60 and P120 under WW. Cultivar ZH had a significantly higher P harvest index and P acquisition efficiency, but a significantly lower shoot and root DW than HD. The interaction between water treatments and P rates had significant effects on leaf and stem P concentration. Cultivar ZH had significantly lower P partitioning to leaves and stems but significantly higher P partitioning to seeds than HD. The seed yield was positively correlated with leaf and seed P accumulations and P acquisition efficiency under WS. We conclude that (1) adequate water supply improved the P mobilization from leaves and stems at maturity, which may have improved the seed yield; and (2) the high P acquisition efficiency is coordination to high P partition to seeds to produce a high seed yield under water- and P-limited conditions.

scholarly journals Cultivar and Spacing Effects on Transmission of Phytophthora parasitica in an Ebb-and-Flow Subirrigation System

Plant Disease ◽  
1997 ◽  
Vol 81 (1) ◽  
pp. 89-95 ◽  
Author(s):  
Stephen S. Strong ◽  
Bridget K. Behe ◽  
C. Fred Deneke ◽  
Kira L. Bowen ◽  
Gary J. Keever
Keyword(s):  
Catharanthus Roseus ◽  
Disease Incidence ◽  
Severe Disease ◽  
Disease Development ◽  
Phytophthora Parasitica ◽  
Spacing Effects ◽  
Ebb And Flow

Phytophthora parasitica was transmitted within 6 weeks from vinca (Catharanthus roseus) plants growing in infested potting mix, on the drain end of ebb-and-flow benches, to plants in noninfested potting mix. Transmission of Phytophthora was very low when potting mix was not pasteurized. When potting mix was steam pasteurized, infection of plants, disease incidence, and severity increased with time and decreased with distance from plants in infested pots. The cultivar Pretty in Pink was more susceptible to infection by P. parasitica than cv. Peppermint Cooler, allowing more rapid and severe disease development as well as pathogen dissemination and transmission. Pot spacing did not significantly affect transmission of P. parasitica on an ebb-and-flow bench.

Influence of fungi on multiplication and distribution of the pine wood nematode, Bursaphelenchus xylophilus, in axenized Pinus thunbergii cuttings

Nematology ◽  
2005 ◽  
Vol 7 (6) ◽  
pp. 809-817 ◽  
Author(s):  
Kazuo Suzuki ◽  
Daisuke Sakaue ◽  
Toshihiro Yamada ◽  
Yu Wang
Keyword(s):  
Population Size ◽  
Early Stage ◽  
Bursaphelenchus Xylophilus ◽  
Pinus Thunbergii ◽  
Disease Development ◽  
Pine Wood Nematode ◽  
Pine Wood ◽  
Inoculation Site ◽  
Fungal Hyphae ◽  
Close Relationship

AbstractInfluence of fungi on multiplication and distribution of the pine wood nematode (PWN), Bursaphelenchus xylophilus, was investigated in Pinus thunbergii cuttings. Axenized nematodes and/or one of two fungi isolated from healthy and PWN-killed P. thunbergii were inoculated together into autoclaved cuttings. A close relationship between the existence and distribution of fungal hyphae, and the multiplication and distribution of PWN was observed. The PWN did not multiply when only axenized nematodes were inoculated in the absence of fungi. When fungi were present, PWN population size increased markedly. The number of nematodes was high at sites where fungal hyphae were distributed. It is suggested that the restriction of a large portion of the nematode population near the inoculation site during the early stage of disease development is closely related to restricted distribution of fungal hyphae.

scholarly journals A Comparative Study of Growth and Nutrition in Barley and Rye As Affected by Low-Water Treatment

1955 ◽  
Vol 8 (4) ◽  
pp. 435 ◽  
Author(s):  
RF Williams ◽  
RE Shapter
Keyword(s):  
Water Stress ◽  
Water Treatment ◽  
Comparative Study ◽  
Plant Parts ◽  
Stage Of Development ◽  
Growth And Nutrition ◽  
Water Treatments

A comparative study of growth and nutrition in barley and rye was made with two water treatments. The low-water treatment was of an intermittent character and harvests were made after each of the five periods of water stress. Yield reductions due to low-water treatment were highly significant at all five harvests and for both species. The severity of the effects on various plant parts was conditioned by the stage of development of those parts.

scholarly journals Water-Stress Influences on Three New Promising HLB-Tolerant Citrus Rootstocks

Horticulturae ◽  
2021 ◽  
Vol 7 (10) ◽  
pp. 336
Author(s):  
Lidia Aparicio-Durán ◽  
Frederick G. Gmitter ◽  
Juan M. Arjona-López ◽  
Rocío Calero-Velázquez ◽  
Áurea Hervalejo ◽  
...  
Keyword(s):  
Water Stress ◽  
Water Status ◽  
Abiotic Factors ◽  
Dry Weight ◽  
Emerging Diseases ◽  
Carrizo Citrange ◽  
Citrus Rootstock ◽  
Chlorophyll Index ◽  
Stress Influences ◽  
Water Treatments

Drought and flooding conditions are increasingly common abiotic factors that affect citrus crops in both the Mediterranean Basin and Florida. Furthermore, emerging diseases, such as Huanglongbing (HLB), are a potential risk for these crops in those producing areas. This study aimed to evaluate the behavior under water-stress treatments of three new citrus rootstocks (UFR-6, B11R5T60, and 2247 x 6070-02-2) with reported tolerance of HLB, comparing them with a common commercial citrus rootstock (Carrizo citrange). Four water conditions were established: Control, Medium Water Stress (MWS), Drought, and Flooding. Chlorophyll index (SPAD), growth in height, relative growth rate, biomass (fresh and dry weight) and plant water status were evaluated. Citru rootstock response were different for each genotype; Carrizo citrange was negatively affected by all water treatments in the chlorophyll index (SPAD) and biomass production. By contrast, UFR-6 showed a positive response in SPAD and growth under MWS and Drought, B11R5T60 displayed similar behavior to Control under all water stresses, and the response of 2247 x 6070-02-2 under MWS treatment was adequate but was not under Drought or Flooding conditions. Our study describes the behavior of these promising new citrus rootstocks against water stress; B11R5T60 exhibiting the best performance. These results can be useful for the citrus industry to address water-stress problems in these crops.

Sign in / Sign up

Export Citation Format

Share Document