Subsoiling in a loblolly pine seed orchard: effects on seed quality

1989 ◽  
Vol 19 (4) ◽  
pp. 505-508
Author(s):  
D. K. Struve ◽  
J. B. Jett ◽  
S. E. McKeand ◽  
G. P. Cannon

An 8-year-old loblolly pine (Pinustaeda L.) seed orchard was subsoiled by making one (single-rip treatment) or three (multiple-rip treatment) parallel rips on opposite sides of the trees. A nonsubsoil (control) treatment was also included. Seeds were extracted and sized into small, medium, and large. Subsoiling treatments had no effect on number or percentage of small, medium, and large seeds. The multiple-rip treatment produced significantly more seeds per cone than the control treatment, but no more than the single-rip treatment. Seed size did not affect seed germination, but strong clonal effects in seed quality and vigor occurred. There was no effect of any of the subsoiling treatments on seed germination. Any subsoiling treatments used to enhance tree vigor or to alleviate soil compaction in a seed orchard should have minimal influence on seed quality.

1996 ◽  
Vol 72 (5) ◽  
pp. 469-473 ◽  
Author(s):  
J. P. Barnett

Tree improvement programs have influenced significantly the quality of southern pine seeds produced when compared to collections from native stands. Seed orchard management practices such as fertilization can increase seed size and reduce seed dormancy. These result in the need for less complex pregermination treatments. Repeated cone collections from the same clones facilitate collections according to ripening (cone specific gravity), which can improve seed germination and storage. However, cultural practices may result in seed properties that are more sensitive to damage during processing procedures and result in lower quality unless special care is provided during this stage of handling. The effect of orchard management practices on seed quality also varies by species, with loblolly pine being less affected than longleaf pine. Key words: Pinus spp., seed germination, seed dormancy, seed storage, cone maturity


2000 ◽  
Vol 132 (3) ◽  
pp. 345-351 ◽  
Author(s):  
Gary L. DeBarr ◽  
James L. Hanula ◽  
Christine G. Niwa ◽  
John C. Nord

AbstractSynthetic sex pheromones released in a loblolly pine, Pinus taeda L. (Pinaceae), seed orchard interfered with the ability of male coneworm moths, Dioryctria Zeller spp. (Lepidoptera: Pyralidae), to locate traps baited with sex pheromones or live females. Pherocon 1C® traps baited with synthetic pheromones or live conspecific females were hung near the center of two 1.2-ha circular plots during emergence of Dioryctria amatella (Hulst), Dioryctria disclusa (Heinrich), and Dioryctria merkeli (Mutuura and Munroe). In a paired design, trap catches for the mating-disruption treatment with synthetic pheromone dispensers consisting of three polyvinyl chloride rods placed in every tree were compared with the control treatment. Treatments were alternated at intervals of 2–3 d. Trap catches of D. amatella were reduced by 91% when plots were treated with 2.5 g/ha of Z-11-hexadencenyl acetate. Catches were reduced by 99.5% for D. disclusa and by 97% for D. merkeli when plots were treated with 12.5 g/ha of Z-9-tetradecenyl acetate, whereas catches of D. amatella were unaffected by this mating-disruption treatment. Daily disappearance of Z-9-tetradecenyl acetate from the dispensers averaged 0.46 g/ha or less. Manually placing dispensers on nylon lines in the tops of trees was an effective method for releasing synthetic Dioryctria pheromones in the orchard. These data suggest it may be feasible to prevent mating of Dioryctria spp. in pine seed orchards by using synthetic pheromones for mating disruption, but large-scale tests will be required to demonstrate cone protection.


Author(s):  
M. Massimi

Seed size may influence seed germination, and seedling vigor. Few investigations are available about the effect of seed size on barley seedling vigor in Jordan. The present study was designed to investigate the impact of seed size on germination percentage, seedling dry weight, seedling vigor index, and germination percentage after accelerated aging in barley. Three seed sizes i.e. large, medium, and small (having diameter of > 2.75 millimeter, 2.5 - 2.75 millimeter, and less than 2.5 millimeter, respectively) were tested in the experiment. Seed quality for different seed size categories was evaluated in the laboratory by measuring seed germination, germination after accelerated aging, as well seedling dry weight and vigor index. Results showed significant differences for large seeds in germination percentages, seedling dry weight and vigor index. It may be concluded that large seed size of barley showed best quality.


1986 ◽  
Vol 10 (4) ◽  
pp. 230-232 ◽  
Author(s):  
H. R. Powers ◽  
J. F. Kraus

Abstract A greenhouse inoculation study compared resistance to fusiform rust (Cronartium quercuum (Berk.) Miyabe ex Shirai f. sp. fusiforme) of loblolly pine (Pinus taeda L.) seedlings derived from bulk seed produced in 4 rust-resistant seed orchards, 1 rust-resistant geographic seed source (Livingston Parish, LA), and a control treatment of improved loblolly from a first-generation production orchard. The rust-resistant orchards included 2 forest industry orchards developed from the most rust-resistant clones available within a tree improvement cooperative (1st generation), and both a clonal and a seedling seed orchard from the Georgia Forestry Commission-USDA Forest Service (GFC-USFS) program (2nd generation). The most resistant seedlings (61% rust free) were from the GFC-USFS seedling orchard. The Livingston Parish seedlings and those from the GFC-USFS clonal orchard had significant resistance, both groups being 44% rust free. One forest industry orchard was intermediate in resistance (34% rust free), whereas the second industry orchard was not significantly different from the controls, with 19 and 13% of the seedlings rust free, respectively. The results emphasize the value of increased selection pressure in the future production of highly rust-resistant seedlings with a broad genetic base, and demonstrates the gains that can be achieved in advanced generations. South. J. Appl. For. 10:230-232, Nov. 1986.


2020 ◽  
Vol 33 (4) ◽  
pp. 878-887
Author(s):  
ELIZETH REGINA RAISSE ◽  
MIQUÉIAS DE OLIVEIRA ASSIS ◽  
EDUARDO FONTES ARAUJO ◽  
FRANCISCO CLÁUDIO LOPES DE FREITAS ◽  
ROBERTO FONTES ARAUJO

ABSTRACT Information about the effect of herbicides on cowpea seed quality is scarce. The objective of this work was to evaluate the effect of using chemical desiccants at pre-harvest on the anticipation of harvest and physiological quality of cowpea seeds of the cultivar BRS-Tumucumaque, before and after storage. Two experiments were conducted: experiment 1 was conducted under a randomized block design, with four replications; the treatments consisted of seven herbicides (carfentrazone-ethyl, saflufenacil, glyphosate, paraquat, flumioxazin, glufosinate-ammonium, and diquat) and a control treatment; anticipation of harvest, and seed water content, germination, and vigor were evaluated. The seeds were stored for six months in controlled environment and not-controlled environment rooms and evaluated for water content, germination, and vigor in Experiment 2, which was conducted in a 7^2+1 factorial arrangement, with four replications; the first factor consisted of the seven herbicides, the second factor was the two storage environments, plus a control treatment. The results showed 3 to 9 days of anticipation of harvest relative to the control. The glufosinate -ammonium herbicide negatively affected seed germination and vigor. The glyphosate herbicide decreased seed germination and vigor after storage. The physiological quality of cowpea seeds at the post -harvest period and after six months of storage was not affected by the carfentrazone-ethyl and flumioxazin herbicides. Paraquat and diquat were the most efficient herbicides for the anticipation of harvest (nine days). Glyphosate and glufosinate -ammonium were the most harmful herbicides to seed physiological quality. The controlled environment room was the most adequate environment for seed conservation.


2017 ◽  
Vol 6 (1) ◽  
pp. 13
Author(s):  
Naning Yuniarti ◽  
Megawati Megawati ◽  
Budi Leksono

Improper seed handling of Eucalyptus pellita will reduce seed quality, so as to improve the viability of the seed proper handling techniques are needed. To investigate the seed germination potency as a result of seed handling germination seed tests are needed. The purpose of this study was to examine the effect of germination method and paper substrate on the viability of E. pellita seeds.  Seeds used in this study were from seedling seed orchard in South Sumatra, South Kalimantan, and Riau. Seed germination methods used in the laboratory tests were method of top paper and between paper tests, besides that, different papers were used such as: paper substrate namely straw paper, towel paper, filter paper, and newspaper. Factorial experimental design completely randomized was used. The results showed that: (1) the method of germination and paper substrate was significant (2) the best paper substrate and germination method was the method of top paper test with used media of newspaper (germination percentage 204 seedling /0.01 grams).


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1473
Author(s):  
Zlatica Mamlic ◽  
Ivana Maksimovic ◽  
Petar Canak ◽  
Goran Mamlic ◽  
Vojin Djukic ◽  
...  

Soybean production in the system of organic agriculture is not very demanding, and this has been well documented both through experimental results and commercial production. However, one of the biggest problems in organic production is the lack of adequate pre-sowing treatments. Therefore, the aim of this study was to examine the effect of the electrostatic field. This is a physical treatment that was first used for seed treatment in the 18th century but has mostly been neglected since then. Seeds of five soybean genotypes with differently colored seed coats (yellow, green, dark green, brown, and black) were included in this study. The seeds were exposed to different values of direct current (DC) with the following voltages: 0 V (control), 3 V, 6 V, and 9 V, to which the seeds were exposed for 0 min (control), 1 min, and 3 min. After exposing the seeds to the electric field, the physiological properties of seeds and seedlings at the first stage of growth were evaluated. The results show that the effect of the electrostatic field on seed quality depends on the genotype, voltage, and exposure time. The application of DC can be a suitable method for improving seed germination and the initial growth of soybean seedlings. In addition, the results indicate that it is necessary to adjust the DC treatment (voltage and duration of exposure of seeds) to particular genotypes since inadequate treatments may reduce the quality of seeds.


1975 ◽  
Vol 5 (3) ◽  
pp. 419-423 ◽  
Author(s):  
Carey Borno ◽  
Iain E. P. Taylor

Stratified, imbibed Douglas fir (Pseudotsugamenziesii (Mirb.) Franco) seeds were exposed to 100% ethylene for times between 0 and 366 h. Germination rate and germination percentage were increased by treatments up to 48 h. The 12-h treatment gave largest stimulation; 30% enhancement of final germination percentage over control. Treatment for 96 h caused increased germination rate for the first 5 days but reduced the germination percentage. Germinants were subject to continuous exposure to atmospheres containing 0.1 – 200 000 ppm ethylene in air, but it did not stimulate growth, and the gas was inhibitory above 100 ppm. Although some effects of high concentrations of ethylene may have been due to the lowering of oxygen supplies, this alone was insufficient to account for the full inhibitory effect. The mechanism of stimulation by short-term exposure to ethylene is discussed.


2021 ◽  
Author(s):  
Paris Lambdin

Abstract This species has had limited distribution from its native habitats in the southern region of the USA since its discovery and description (Lobdell, 1930). O. acuta appears to be restricted to feeding on species of pines and loblolly pine, Pinus taeda, is its preferred food source. In its native habitat, populations seldom reach pest status due to the presence of natural enemies. In 1988, it was transported to a pine seed orchard in China on slash pine, Pinus elliottii, scions purchased in the USA. Sun et al. (1996) noted that O. acuta-infested slash pine scions leaving the USA and entering China in 1988 were not subjected to the quarantine restrictions of either country. The loblolly pine mealybug quickly became established and rapidly spread throughout pine plantations in the Guangdong Province, China where it threatens both native and introduced species of pines in the region.


Weed Science ◽  
2021 ◽  
pp. 1-19
Author(s):  
Bhagirath S. Chauhan ◽  
Shane Campbell ◽  
Victor J. Galea

Abstract Sweet acacia [Vachellia farnesiana (L.) Willd.]is a problematic thorny weed species in several parts of Australia. Knowledge of its seed biology could help to formulate weed management decisions for this and other similar species. Experiments were conducted to determine the effect of hot water (scarification), alternating temperatures, light, salt stress, and water stress on seed germination of two populations of V. farnesiana and to evaluate the response of its young seedlings (the most sensitive development stage) to commonly available POST herbicides in Australia. Both populations behaved similarly to all the environmental factors and herbicides; therefore, data were pooled over the populations. Seeds immersed in hot water at 90 C for 10 min provided the highest germination (88%), demonstrating physical dormancy in this species. Seeds germinated at a wide range of alternating day/night temperatures from 20/10 C (35%) to 35/25 C (90%) but no seeds germinated at 15/5 C. Germination was not affected by light, suggesting that seeds are nonphotoblastic and can germinate under a plant canopy or when buried in soil. Germination was not affected by sodium chloride concentrations up to 20 mM and about 50% of seeds could germinate at 160 mM sodium chloride, suggesting its high salt tolerance ability. Germination was only 13% at −0.2 MPa osmotic potential and no seeds germinated at −0.4 MPa, suggesting that V. farnesiana seeds may remain ungerminated until moisture conditions have become conducive for germination. A number of POST herbicides, including 2,4-D + picloram, glufosinate, paraquat and saflufenacil, provided >85% control of biomass of young seedlings compared with the nontreated control treatment. Knowledge gained from this study will help to predict the potential spread of V. farnesiana in other areas and help to integrate herbicide use with other management strategies.


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