Effects of temperature during bud burst on pear thrips damage to sugar maple

1992 ◽  
Vol 22 (8) ◽  
pp. 1147-1150 ◽  
Author(s):  
T.E. Kolb ◽  
D.A.J. Teulon

Sugar maple (Acersaccharum Marsh.) seedlings were exposed to either cool (11.9 °C) or warm (18.2 °C) temperatures in the presence or absence of adult pear thrips (Taeniothripsinconsequens Uzel) during bud burst and early spring growth. Time required for spring stem elongation was shorter at the warm temperature than at the cool temperature. Thrips feeding reduced height, leaf area, and seedling dry weight at both temperatures, and reductions were greater at the cool temperature than at the warm temperature. The results indicate that cool temperatures that slow bud burst promote pear thrips damage to sugar maple leaves.

1983 ◽  
Vol 13 (5) ◽  
pp. 986-994 ◽  
Author(s):  
Stephen D. Ross

The enhanced stem elongation that frequently accompanies the gibberellin A4/7 (GA4/7) promotion of flowering in Pinaceae species was investigated for Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) vegetative propagules in relation to their physiological age, GA4/7 concentration, and treatment timing. Maximum growth enhancement, but marginal promotion of flowering (males and females), occurred when GA4/7 was applied in early spring before vegetative buds had begun to swell. In contrast, shoot elongation was only slightly enhanced when GA4/7 treatment was timed (vegetative bud burst ±4.5 weeks) to bracket the critical period for effecting differentiation of axillary primordia into cone buds. Also, the GA4/7 concentration optimal for flowering was supraoptimal for shoot elongation, and the growth response to GA4/7 decreased, whereas the flowering response increased, with increasing physiological age of the propagules (scions 4–45 years old). These findings are consistent with a hypothesis that exogenous GA4/7 is first utilized for vegetative growth processes, increased flowering occurring only after a threshold concentration is reached.


1994 ◽  
Vol 12 (3) ◽  
pp. 150-154
Author(s):  
Joyce G. Latimer ◽  
Sherrod A. Baden

Abstract In 1988, spray applications of 3.5 or 7 ppm paclobutrazol, 1500 ppm chlormequat, or 200 ppm ancymidol were applied to seed geraniums (Pelargonium x hortorum L. H. Bailey ‘Ringo White’ and ‘Ringo Rose’) to determine effects on growth in the greenhouse and the subsequent growth and performance of treated plants in the landscape. All growth retardants reduced stem length and shoot dry weight as well as time required for flowering, while branching was increased relative to the untreated plants. Flowering in the landscape was increased by all growth regulator treatments at 4 weeks after planting but was generally not different from the untreated plants at 6 weeks after planting. Plant height and width were reduced by all treatments for both cultivars, relative to untreated plants, at 4 weeks after planting. However, only 7 ppm paclobutrazol reduced height and width of ‘Ringo White’ plants at 6 weeks after planting. Plant height, but not width, was reduced by all treatments for ‘Ringo Rose’ at 6 weeks after planting. In 1989, seedlings of ‘Ringo Rose’ were treated with 3.5, 7, 16, 40, or 80 ppm paclobutrazol or 1500 ppm chlormequat or 200 ppm ancymidol. Seedling growth was excessively reduced by 40 or 80 ppm paclobutrazol. Time required for flowering was not reduced by growth regulators in 1989. Landscape performance under conditions of excess rain was not improved by plant growth regulators and the height of plants treated with 16, 40 or 80 ppm paclobutrazol was still less than that of the untreated plants at 12 weeks after planting. Only chlormequat controlled plant growth in the greenhouse without delaying the resumption of growth in the landscape.


Weed Science ◽  
1974 ◽  
Vol 22 (5) ◽  
pp. 469-475 ◽  
Author(s):  
James A. Young ◽  
Raymond A. Evans

The configuration of the growth pattern forChrysothamnus viscidiflorus(Hook.) Nutt. was determined from vegetative bud burst to flowering. Important portions of the pattern are: restrictive growth during early spring, accelerated growth in late spring when the optimum susceptibility to herbicides occurs, and a leveling off of growth before flowering. Seedlings and young plants have a more rapid and greater annual stem elongation than mature or senescent plants. Elongation during the accelerated growth period can be predicted from early spring growth with moderate precision when soil moisture and temperatures are not limiting. Populations growing on sites of higher or lower elevations or of pronounced aspect will have growth patterns moderately varying from the modal populations. The greatest factor influencing the growth pattern on years with adequate soil moisture was competition from other species and the combination of competition and age of the rabbitbrush plants.


TAPPI Journal ◽  
2012 ◽  
Vol 11 (7) ◽  
pp. 29-35 ◽  
Author(s):  
PETER W. HART ◽  
DALE E. NUTTER

During the last several years, the increasing cost and decreasing availability of mixed southern hardwoods have resulted in financial and production difficulties for southern U.S. mills that use a significant percentage of hardwood kraft pulp. Traditionally, in the United States, hardwoods are not plantation grown because of the growth time required to produce a quality tree suitable for pulping. One potential method of mitigating the cost and supply issues associated with the use of native hardwoods is to grow eucalyptus in plantations for the sole purpose of producing hardwood pulp. However, most of the eucalyptus species used in pulping elsewhere in the world are not capable of surviving in the southern U.S. climate. This study examines the potential of seven different cold-tolerant eucalyptus species to be used as replacements for, or supplements to, mixed southern hardwoods. The laboratory pulping and bleaching aspects of these seven species are discussed, along with pertinent mill operational data. Selected mill trial data also are reviewed.


1981 ◽  
Vol 11 (2) ◽  
pp. 288-291
Author(s):  
Bruce W. Wood ◽  
James W. Hanover

A method is described for accelerating growth of sugar maple (Acersaccharum Marsh.) seedlings for early progeny and provenance evaluation and plantation establishment. Outdoor nursery production methods produced relatively small seedlings, few seed-lot differences, and no provenance differences in seedlings 4 and 16 months of age. In contrast, accelerated seedlings exhibited pronounced seed-lot and provenance differences at both ages and had a 29 and 80% height superiority at 4 and 16 months, respectively. Provenance differences in height, budbreak, nodes, and growth flushes revealed by the accelerated treatment and supplemented by seed characteristics indicate existence of Upper and Lower Peninsula races in Michigan. Accelerated growth techniques may have considerable potential for reducing the time required for genotypic evaluation of sugar maple and possibly other tree species, but results must be substantiated by subsequent field observations.


IAWA Journal ◽  
2016 ◽  
Vol 37 (2) ◽  
pp. 315-331 ◽  
Author(s):  
Peter Kitin ◽  
Ryo Funada

This paper reviews the development of xylem vessels in ring-porous dicots and the corresponding leaf phenology. Also included are our original observations on the time-course of vessel element growth, secondary wall deposition, and end wall perforation in the deciduous hardwood Kalopanax septemlobus. Different patterns of xylem growth and phenology serve different strategies of the species for adaptation to seasonal climates. Trees with ring-porous xylem form wide earlywood vessels (EWV) in spring and narrow latewood vessels in summer. The wide EWV become embolized or blocked with tyloses by the end of the growing season while the narrow vessels may remain functional for many years. The co-occurrence of wide and narrow vessels provides both efficiency and safety of the water transport as well as a potentially longer growing season. It has for a long time been assumed that EWV in ring-porous hardwoods are formed in early spring before bud burst in order to supply sap to growing leaves and shoots.However, the full time-course of development of EWV elements from initiation of growth until maturation for water transport has not been adequately studied until recently. Our observations clarify a crucial relationship between leaf maturation and the maturation of earlywood vessels for sap transport. Accumulated new evidence shows that EWV in branches and upper stem parts develop earlier than EWV lower in the stem. The first EWV elements are fully expanded with differentiated secondary walls by the time of bud burst. In lower stem parts, perforations in vessel end walls are formed after bud burst and before the new leaves have achieved full size. Therefore, the current-year EWV network becomes functional for water transport only by the time when the first new leaves are mature.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6797 ◽  
Author(s):  
Hilmar Hinz ◽  
Olga Reñones ◽  
Adam Gouraguine ◽  
Andrew F. Johnson ◽  
Joan Moranta

The nursery function of coastal habitats is one of the most frequently mentioned and recognized ecosystem services in the valuation of coastal ecosystems. Despite its importance our understanding of the precise habitat parameters and mechanisms that make a habitat important as a nursery area is still limited for many species. The study aimed to establish the importance of different algae morphotypes in providing shelter and food for juvenile coastal fish during the main settlement peaks, in early spring and late summer, in littoral rocky reef systems in the Northwestern Mediterranean. The results of our study showed strong seasonal differences in algae cover, composition and height between the two sampling periods. Overall, during spring the algae were well developed, while in late summer, both density and height, of most algae decreased considerably. Equally, prey biomass, in form of suitable sized invertebrate fauna associated to the algae, decreased. Accordingly, the shelter and food for the fish settling in this habitat during late summer were less abundant, indicating a mismatch between the observed presence of juvenile fish and optimal habitat conditions. Differences in prey densities were detected between algae morphotypes, with structurally more complex algae, such as Cystoseira spp. and Halopteris spp. consistently containing more prey, independent of season, compared to simpler structured morphotypes such as Dictoytales. The study furthermore related juvenile fish density to habitats dominated by different algae morphotypes. Out of the three-study species (Diplodus vulgaris, Symphodus ocellatus, Coris julis) only S. ocellatus showed a significant association with an algae habitat. S. ocellatus related positively to habitats dominated by Dictoytales which provided the highest cover during late summer but had the lowest prey densities. A strong association of this species with Cystoseira, as reported by other studies, could not be confirmed. Cystoseira was abundant within the study area but in a state of dieback, showing loss and reduced height of foliage, typical for the time of year within the study area. It is therefore likely that algae-fish associations are context-dependent and that several algae species may fulfil similar functions. We also discovered that prey biomass did not appear to have an important effect on juvenile abundances. Nevertheless, the availability of prey may influence juvenile fish condition, growth performance and ultimately long-term survival. We therefore suggest that future studies on habitat quality should also include, besides abundance, indicators related to the condition and growth of juveniles.


2013 ◽  
Vol 31 (1) ◽  
pp. 39-42
Author(s):  
Joshua R. Pool ◽  
Jason J. Griffin ◽  
Cheryl R. Boyer ◽  
Stuart L. Warren

The Midwest and southern Great Plains are known for historic and severe droughts. More common, however, are short-term recurring drought events that can limit tree survival. The pressure of environmental stress combined with numerous diseases and pests are decimating existing Pinus L. spp. (pine) plantings and driving the effort to identify alternative species. Four species of conifer were subjected to recurring moderate or severe drought to observe the effects on growth and photosynthesis. Species evaluated were: Abies nordmanniana (Nordmann fir), Cupressus arizonica (Arizona cypress), Picea engelmannii (Engelmann spruce), and Thuja × ‘Green Giant’ (‘Green Giant’ arborvitae). Recurring drought reduced height and growth index of T. × ‘Green Giant’. However, photosynthesis and root growth were unaffected by drought treatments. In contrast, reduced Pnet was the only detectable effect of recurring drought in P. engelmannii. Growth of A. nordmanniana was not affected by drought. When subjected to drought, C. arizonica reduced shoot dry weight, while maintaining photosynthesis and root growth. Overall, C. arizonica was able to maintain growth of roots and shoots as well as maintain photosynthesis which may be an advantage in the harsh climate of the Midwest and southern Great Plains.


2020 ◽  
Vol 1 (1) ◽  
pp. 45-49
Author(s):  
Tsotne Samadashvili ◽  
Gulnari Chkhutiashvili ◽  
Mirian Chokheli ◽  
Zoia Sikharulidze ◽  
Qetevan Nacarishvili

Wheat is a vital crop in Georgia and in the world. Because of the increase in the rate of population growth, improving the grain yield is the way to meet food demand. Proper crop nutrition plays a vital role in maintaining the world’s food supply. Fertilizer is essential for accomplishing this.One of the most important means for increasing the wheat yield is fertilizer, especially, organic fertilizer. The present research was carried out to study the effects of different doses (150ml, 200ml and 300 ml on ha) of humic organic fertilizer “Ecorost” on yield of winter wheat cultivar “Tbilisuri 15”. The humic liquid fertilizer "Ecorost" is a peat-based organic-mineral fertilizer. The product is active and saturated due to the use of the latest technology and living bacteria found in peat. The field trials were conducted in 2017-2019 at the Experimental Site of Scientific Research Center of Agriculture in Dedopliskharo- arid region (Eastern Georgia).Liquid fertilizer was applied two times: in tillering stage in early spring and two weeks after - in stem elongation stage. Results indicated that the highest wheat grain yield (4t/ha) was achieved when the plants were fertilized with 300 ml on 1 ha ofEcorost. Applications of liquid fertilizer “Ecorost” increased grain yield of winter wheat by 16.2% in comparison with standard nitrogen fertilization. Thus, liquid fertilizer “Ecorost” had a significant effect on wheat grain yield compared to control standard nitrogen fertilizer.


2020 ◽  
Vol 34 (6) ◽  
pp. 807-813
Author(s):  
Benjamin H. Lawrence ◽  
Jason A. Bond ◽  
Bobby R. Golden ◽  
Thomas W. Allen ◽  
Daniel B. Reynolds ◽  
...  

AbstractOff-target paraquat movement to rice has become a major problem in recent years for rice producers in the midsouthern United States. Nitrogen (N) fertilizer is applied to rice in greater quantity and frequency than all other nutrients to optimize rice yield. Two separate field studies were conducted from 2015 to 2018 in Stoneville, MS, to assess whether starter N fertilizer can aid rice recovery from exposure to a sub-lethal concentration of paraquat and to evaluate rice response to different N fertilizer management strategies following exposure to a sub-lethal concentration of paraquat. In both studies, paraquat treatments consisted of paraquat at 0 and 84 g ai ha–1 applied to rice in the two- to three-leaf (EPOST) growth stage. In the starter fertilizer study, N fertilizer at 24 kg ha–1 as ammonium sulfate (AMS) was applied to rice at spiking- to one-leaf (VEPOST), two- to three-leaf (EPOST), or three- to four-leaf (MPOST) growth stages before and after paraquat treatment. In the N fertilizer timing study, N fertilizer at 168 kg N ha–1 was applied in a single four-leaf to one-tiller (LPOST) application or two-, three-, and two four-way split applications. Despite starter N fertilizer applications, paraquat injured rice ≥41%, reduced height 57%, reduced dry weight prior to flooding 77%, delayed maturity 10 d, reduced dry weight at maturity 33%, and reduced rough rice yield 35% in the starter fertilizer study. Similarly, in the N fertilizer timing study, paraquat injured rice ≥45%, reduced height 14%, delayed maturity 10 d, reduced dry weight at maturity 44%, and reduced rough rice yield 50% for all N fertilizer management strategies. Both studies indicate that severe complications in growth and development can occur from rice exposure to a sub-lethal concentration of paraquat. In both studies, manipulation of N fertilizer management did not facilitate rice recovery from early-season exposure to paraquat.


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