Effect of light, nitrogen fertilization, and mycorrhizal fungi on growth and photosynthesis of lodgepole pine seedlings

1983 ◽  
Vol 13 (6) ◽  
pp. 1099-1106 ◽  
Author(s):  
S. A. Ekwebelam ◽  
C. P. P. Reid

Seedlings of lodgepole pine (Pinuscontorta Dougl.) were grown for 10 weeks without eetomycorrhizae in the greenhouse at three levels of irradiance (low, medium, and high) and ammonium nitrate (3, 62, and 248 ppm N). At 10 weeks, inoculation with either Pisolithustinctorius (Pers.) Coker and Couch or Suillusgranulatus (L. ex Fr.) O. Kuntze was superimposed on light and nitrogen treatments, and the seedlings were grown for an additional 6 weeks. Mycorrhiza formation increased with increase in irradiance, while fertilization with 62 ppm N resulted in greater mycorrhiza formation than either 3 or 248 ppm N. Further, inoculated plants had significantly greater biomass and took up more phosphorus than nonmycorrhizal seedlings. Inoculation with P. tinctorius and S. granulatus resulted in photosynthetic rates of 1.87 and 1.85 mg CO2•dm−2•h−1, respectively, significantly greater than nonmycorrhizal plants (1.41 mg CO2•dm−2•h−1). Although the increase in growth of the mycorrhizal seedlings was associated with increased photosynthesis, the magnitude of this response depended on specific combinations of irradiance and nitrogen fertilization. These results emphasize the importance of interactions among irradiance, nitrogen fertilization, and mycorrhiza development in the growth of containerized seedlings.

1989 ◽  
Vol 19 (6) ◽  
pp. 685-689 ◽  
Author(s):  
Martin S. Mugala ◽  
Peter V. Blenis ◽  
Yasuyuki Hiratsuka ◽  
Kenneth I. Mallett

Two experiments were conducted to test the hypothesis that white spruce (Piceaglauca (Moench) Voss) is less liable than lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) to be attacked by Alberta isolates of Armillaria. In the first experiment, 27 two-year-old containerized pine and spruce were inoculated with each of 19 different isolates representing North American biological species (NABS) I and V, the Foothills variant of NABS I, and A. mellea s.str. In the second experiment, 10 containerized seedlings of both species were inoculated with eight different isolates of NABS I and transferred to 2-L pots 2 months later. Inoculum survived better in association with spruce seedlings than with pine. In both experiments, spruce seedlings were more frequently infected than pine seedlings, and more likely to die when infected, although this difference was significant only in the first experiment. Favoring or planting spruce on sites with Armillaria root rot, therefore, cannot be recommended in Alberta.


1969 ◽  
Vol 49 (2) ◽  
pp. 149-154 ◽  
Author(s):  
J. L. Mason

Nitrogen treatments from 0.15 to 0.90 kg of nitrogen and cultivation treatments from zero to three shallow rotovations were applied in a split-plot design to 30-year-old McIntosh apple trees growing in irrigated grass sod.Fruit quality was very largely unaffected by the treatments. Pressure test after harvest was reduced from 6.61 to 6.44 kg (P = 0.10) as nitrogen increased. Number of rots increased from 2.7 to 3.9 per 60-fruit sample with increasing nitrogen. Titratable acidity and soluble solids after harvest and pressure test, titratable acidity, soluble solids, stem-cavity browning and core flush in tests after storage were all unchanged. In addition, none of these tests were affected by cultivation except pressure test, which decreased with more cultivation (P = 0.10).Yield was not changed by either the nitrogen or the cultivation treatments, and terminal length increased only slightly with more cultivation. However, nitrogen concentration in the leaf was increased from 1.90 to 1.98% by the nitrogen treatments and from 1.83 to 1.98% by increasing cultivation. Extra Fancy grade was reduced and C grade increased by increasing nitrogen (P = 0.10), but cultivation had no effect.The conclusion is drawn that grass sod can very largely eliminate the effect of widely different nitrogen fertilization levels on McIntosh apple, and that moderate cultivation changes this effect only slightly. In many mature orchards of high initial fertility, nitrogen fertilizer may be required in only small amounts or even not at all for optimum fruit color.


1992 ◽  
Vol 22 (8) ◽  
pp. 1089-1093 ◽  
Author(s):  
R. Trowbridge ◽  
F.B. Holl

An overdense lodgepole pine (Pinuscontorta Dougl. ex Loud.) stand was knocked down and the site was prepared by broadcast burn, windrow burn, or mechanical forest floor removal. Inoculated alsike clover (Trifoliumhybridum L.) was seeded at 0, 10, 20, and 30 kg/ha for the three different site preparation treatments to determine the effects of (i) site preparation on infection and effectiveness of the clover–Rhizobium symbiosis and clover percent cover and (ii) the clover–Rhizobium N2-fixing symbiosis on survival, early growth, and foliar nitrogen concentration of lodgepole pine seedlings. The N2-fixing symbiosis established well in all treatments. Clover percent cover increased with increasing rate of seeding, although by relatively few percent in the clover seeded plots. Broadcast burning, windrow burning, and mechanical forest floor removal did not affect the establishment of the N2-fixing symbiosis or clover percent cover. Lodgepole pine survival was not affected by the seeding treatments in any year, nor were height measurements during the first three growing seasons. Seedling height was slightly less in clover-seeded plots compared with controls in the fourth growing season. Lodgepole pine seedlings on clover-seeded plots had decreased diameter growth compared with controls during the first three growing seasons, but incremental diameter growth no longer showed this effect by the fourth growing season. Needle mass (g/100 needles) was less in clover-seeded plots at the end of the second growing season, but this effect was reversed by the fourth growing season, when both needle mass and foliar nitrogen concentration in lodgepole pine foliage were greater in clover-seeded plots.


1983 ◽  
Vol 13 (4) ◽  
pp. 657-665 ◽  
Author(s):  
Jennifer L. Parke ◽  
R. G. Linderman ◽  
J. M. Trappe

The presence of ectomycorrhizal and vesicular–arbuscular (VA) mycorrhizal fungi in soils from five sites in a mixed conifer zone in southwest Oregon, each consisting of a 1- to 1.5-year-old clear-cut adjacent to an undisturbed forest stand, was determined by bioassay with Pseudotsugamenziesii (Mirb.) Franco, Pinusponderosa Dougl. ex P. Laws & C. Laws, and Trifoliumsubterraneum L. 'Mt. Barker' as hosts grown at root zone temperatures ranging from 7.5 to 35 °C. Maximum formation of both ectomycorrhizae and VA mycorrhizae occurred at 18.5–24 °C in soils from all sites, and there were no significant qualitative or quantitative differences between disturbed (clear-cut) or undisturbed (forest) soils. Mycorrhiza formation was moderate even at the lowest temperature tested (7.5 °C) but was greatly reduced or prevented at or above 29.5 °C. Treatment of soil at 35 °C for 1 week did not appear to adversely affect viability of ectomycorrhizal fungus propagules, but young mycorrhizae subjected to the same treatment appeared to be severely injured. Thus the ability of native mycorrhizal fungi to grow at low soil temperatures is especially important as they may contribute to the survival of seedlings outplanted into climatic zones characterized by warm, dry summers following cool, wet winters and springs.


Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 233 ◽  
Author(s):  
Lorenzo Guerrini ◽  
Marco Napoli ◽  
Marco Mancini ◽  
Piernicola Masella ◽  
Alessio Cappelli ◽  
...  

Flour from old varieties are usually considered very weak flours, and thus difficult to use in breadmaking especially when processed as Italian “Tipo 2” flour. Hence, the aim of our study was to understand if agronomic treatments can be used to improve flour processability and the quality of three old wheat varieties. An experimental strip-plot scheme was used: three old wheat varieties (Andriolo, Sieve, Verna), two seeding densities, three levels of nitrogen fertilization (N35, N80, and N135), and two levels of foliar sulfur fertilization. Analyzed parameters related to kernel composition, dough rheology and bread quality. Sulfur and nitrogen treatments significantly affected protein composition and dough alveograph strength, which increased by about 34% with nitrogen fertilization, and by about 14% with the sulfur treatment. However, only nitrogen fertilization affected bread characteristics. Crumb density significantly decreased from N35 to N135, while springiness and cohesiveness increased. On the other hand, sulfur did not improve breads. This highlight the importance of performing breadmaking tests in addition to the rheological determinations. The poor technological performance of old wheat flours can be improved with agronomical treatments designed to obtain higher-quality bread.


1976 ◽  
Vol 6 (3) ◽  
pp. 341-347 ◽  
Author(s):  
S. Thompson

Sequential observations in lodgepole pine (Pinuscontorta Dougl.) and Scots pine (P. sylvestris L.) showed that the second season's shoot was not produced solely from stem units in the terminal resting bud as previously assumed. The stem units held in the rosette of primary needles surrounding the terminal bud elongated to form most of the second season's shoot. The terminal bud only contributed 29 to 54% of the stem units. There was a marked difference between an inland and a coastal provenance of lodgepole pine in the appearance of the shoot apex at the end of the first growing season.


1998 ◽  
Vol 74 (4) ◽  
pp. 578-582 ◽  
Author(s):  
J. M. Kranabetter ◽  
R. Trowbridge

Legumes were tested for their ability to increase soil N content and improve growth of lodgepole pine (Pinus contorta Dougl. ex Loud.) seedlings in west-central British Columbia. A trial with alsike clover at varying densities were tested at one site, while three legume species (alsike clover, birdsfoot trefoil, and white clover) were tested on a second site. After five years of legume cover, mineralizable N mass of the forest floor were 0.5 to 4.5 times those of controls. Total N of the forest floor more than doubled in the seeding density study compared with controls, but was insignificant in the multiple species study. Despite observed increases in soil nitrogen, lodgepole pine growth was not enhanced by the legume treatments. Factors such as N immobilization, root distribution, low S levels, and competition for B may have limited the response of lodgepole pine seedlings to additions of biologically fixed-N. Key words: nitrogen-fixation, legumes, lodgepole pine, soil nitrogen


1970 ◽  
Vol 10 (45) ◽  
pp. 410
Author(s):  
JR Simpson ◽  
JA Bull

Ammonium nitrate, applied in winter and in spring (at head emergence) increased the seed yield of a commercial crop of Demeter fescue (Festuca arundinacea) by up to 54 per cent. The nitrogen treatments each involved a total of 90 lb nitrogen an acre, which was divided differently between the two times of application. The early nitrogen applications increased the number of fertile tillers, but not the yield per tiller, whereas late applications increased only the yield per tiller. The germination percentage of the seed was affected only transiently by nitrogen treatments, but seed size was increased by the late nitrogen application. Thus the number of viable seeds per unit weight of sample was reduced by late nitrogen. The greatest yield of viable seeds was produced by a combination of 60 lb nitrogen in early August and 30 lb nitrogen in late September at heading.


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