Carp seed transportation and distribution.

Author(s):  
Mahmud Hasan

Abstract Carp seed trading has become an important enterprise to make money for hatchery/nursery owners and seed traders, engaging more than 100,000 people in Bangladesh. Aquaculture, in particular carp production, has increased dramatically with the introduction of artificial propagation. The bottleneck of artificial propagation has been removed with successful induced breeding. Induced breeding has been introduced into Bangladesh in the 1980s and since then carp seed production and trading have increasingly become the driving force for the dramatic expansion of aquaculture. Private hatcheries/nurseries have been dominating by producing about 97% of the total seed production. As a result, carp seed trading has become an important entrepreneurship.

2006 ◽  
Vol 28 (2) ◽  
pp. 45-52 ◽  
Author(s):  
Armando Martins dos Santos ◽  
Luis Mauro Gonçalves Rosa ◽  
Lucia Brandão Franke ◽  
Carlos Nabinger

The experiment was carried out in pots in a glasshouse, with one plant per pot and nine repetitions per treatment. The treatments consisted of free or restricted leaves, submited to 90-100% or 60-70% soil field capacity (FC). Only independent effects of water availability or leaf movement were observed on yield components. Plants under well-watered conditions and with freely orienting leaves were taller, and had a larger number of ramifications. The greater development favored the setting of a higher number of inflorescences per plant in these treatments. This behavior resulted in a high number of flowers, green and mature legumes per plant, thus resulting in high seed production which was the most evident response to water availability. Although individual seed weight was higher in the water stress treatment, total seed production was higher for well-watered plants, with no statistically significant effect of leaf movements.


1990 ◽  
Vol 115 (2) ◽  
pp. 245-251 ◽  
Author(s):  
J.O. Payero ◽  
M.S. Bhangoo ◽  
J.J. Steiner

The effects of six applied N treatments differing by rates and frequencies of application on the yield and quality of pepper (Capsicum annuum var. annuum L. `Anaheim Chili') grown for seed was studied. The timing of N applications was based on crop phenology, leaf petiole nitrate-nitrogen concentrations (NO3-N) minimum thresholds, and scheduled calendar applications of fixed amounts of N. Solubilized NH4NO3 was applied through a trickle-irrigation system to ensure uniform and timely applications of N. Rate of mature (green and red) fruit production was unaffected by any treatment except weekly applications of 28 kg·ha-1 of N, which stopped production of mature fruit before all other treatments. Early season floral bud and flower production increased with increasing amounts of N. The two highest total N treatments produced more floral buds and flowers late in the season than the other treatments. Total fruit production was maximized at 240 kg N/ha. Differences in total fruit production due to frequency of N application resulted at the highest total N level. Red fruit production tended to be maximized with total seasonal applied N levels of 240 kg·ha-1 and below, although weekly applications of N reduced production. Total seed yield was a function of red fruit production. Pure-1ive seed (PLS) production was a function of total seed production. Nitrogen use efficiency (NUE) for red fruit production also decreased with N rates >240 kg·ha-1, but PLS yield and NUE decreased in a near-linear fashion as the amount of total seasonal applied N increased, regardless of application frequency. Season average NO3-N (AVE NO3-N) values >4500 mg·kg-1 had total seed and PLS yields less than those treatments <4000 mg·kg-1. Six-day germination percentage was reduced with weekly N applications of 14 kg·ha-1. Seed mass was reduced with weekly N applications of 28 kg·ha-1. Final germination percent, seedling root length and weight, and field emergence were unaffected by any of the N treatments. These findings indicate that different N management strategies are needed to maximize seed yield compared to fruit yield and, therefore, there may be an advantage to growing `Anaheim Chili' pepper specifically for seed.


2004 ◽  
Vol 55 (4) ◽  
pp. 389 ◽  
Author(s):  
K. V. Cunliffe ◽  
A. C. Vecchies ◽  
E. S. Jones ◽  
G. A. Kearney ◽  
J. W. Forster ◽  
...  

Ryegrass species are among the most important species in sown pastures, turf settings, and weed populations worldwide. Perennial ryegrass (Lolium perenne L.) is an outcrossing, wind-pollinated grass. Recent research has demonstrated the feasibility of developing transgenic perennial ryegrass varieties. In order to model the consequences of gene flow from transgenic grass genotypes in a field situation, the model non-transgenic trait of fertility among autotetraploid genotypes was chosen. Gene flow over distance and direction from a donor plot to surrounding sexually compatible recipient plants was studied. Reproductive isolation was achieved through the fertility barrier that arises between tetraploid and diploid ryegrass genotypes, despite the presence of diploid plants in a meadow situation. Fertility was used as an indication of effective gene flow over distance and direction. Measures of the fertility of recipient plants included total seed production (TSP), floret site utilisation (FSU), and relative fertility of recipient plants as a percentage of those within the donor plot (RF%). A leptokurtic distribution for gene flow was identified, with differences in the rate of decline over distance depending on direction. Simple sequence repeat (SSR) polymorphism was used to identify the paternity of progeny plants. The proportional representation of parents among the progeny was not significantly different from that expected due to the numerical representation of the different donor parent genotypes. The results of this research will have important implications for risk analysis prior to the field release of transgenic ryegrasses, fescues, and other pasture grass species, and for seed production in terms of cultivar purity and optimum isolation distance.


2019 ◽  
Vol 126 ◽  
pp. 00064
Author(s):  
A.S Alchimbayeva ◽  
Lyudmila Shibryaeva ◽  
Zharylkasyn Sadykov ◽  
Mikhail Chaplygin ◽  
Rizvankoul Kaimova

In general, the state of seed production in Kazakhstan can be characterized by the following figures. According to Kostanay branch of Kazakh research Institute of mechanization and electrification of agriculture total requirement of seeds is around 2 million tons. These farms provide 70% of the Republic'sfarms with seeds, the remaining 30% are imported from Russia. The studies have shown that all grain-producing regions of Kazakhstan can be classified into three categories according to the annual gross grain harvest, respectively, 16; 15; 3.26 and 2.9 million tons. It is advisable that typical seed farms have the following characteristics: in the first category of regions — the average area of one farm — 2.8 thousand hectares, the average annual grain harvest — 8.06 thousand tons, agro term — 10 days, the required total seed collection -1.78 million tons for all seed farms in the amount of 220 units. Accordingly, in the second category of regions — 1100 hectares; 2.82 thousand tons; 9.5 days 360 thousand tons and 128 units. In a third category — 322 hectares of 1.02 million tons, or 9.1 days, 320 thousand tons and 312 units. Total number of typical specialized farms should be approximately 660 units.


1981 ◽  
Vol 11 (3) ◽  
pp. 512-516 ◽  
Author(s):  
Michael N. Todhunter ◽  
R. Brooks Polk

Seed and cone production in Pinusbanksiana Lamb. was studied using clonal material. Variables studied included sound seed per cone, sound seed percentage, seed efficiency, total seed per cone, seed potential, and total number of cones in relation to site, clone, and position in the crown. The clonal effect was highly significant for all variables. Site and crown location were significant for all but seed total and number of cones. Due to the variability present, cone and seed production should be taken into account in seed orchard design, tree selection, and breeding.


1974 ◽  
Vol 14 (71) ◽  
pp. 749 ◽  
Author(s):  
PG Ozanne ◽  
KMW Howes

The effects of four common fertilizers containing calcium on seed production in subterranean clover (Trifolium subterraneum) were measured at six locations over five years in a total of fifteen field experiments. Calcium as a sulphate, carbonate or phosphate salt was applied to subterranean clover pastures either at the start of the growing season (autumn) or at flowering (spring). Gypsum, plaster of Paris, or lime gave large increases in seed yield per unit area and also per unit weight of tops. Spring applications of superphosphate increased seed yields in only two out of four experiments. Gypsum applied in spring at 200-500 kg ha-1 was as effective as 2,000 kg ha-1 of lime applied in autumn. Applications of lime in spring were much less effective. Increased seed yields were due to increases in burr yield, seed number per burr, and mean weight per seed. They were usually accompanied by increases in calcium concentration in the seed. Responses in seed production to calcium applications were obtained in all three sub-species of Trifolium subterraneum. In two experiments, newly sown on a soil type on which subterranean clover regeneration and persistence is commonly very poor, applied calcium doubled or quadrupled seed set. In 13 experiments using soils on which subterranean clover had persisted as the major component of the pasture for several years, calcium in the year of application increased the total seed bank by 6 to 31 per cent, and the current seed set by a greater amount.


1995 ◽  
Vol 35 (8) ◽  
pp. 1101
Author(s):  
GM Lodge

Field experiments were conducted in a predominantly summer rainfall environment to investigate burr burial, seed production, seed characteristics, seedling emergence and survival, and the effects of time of sowing on 3 Trifolium subterraneum var. brachycalycinum lines (cv. Clare and 2 local lines). Each line produced more surface than buried burrs; surface burrs were 59% (range 56-62%) of the total number of burrs recovered and produced 59% of the total seed number. Numbers of seeds per burr were similar for surface and buried burrs, however, buried seeds were 0.97 mg heavier (P<0.05) than surface seeds. Storage for 5 months at 25/60�C decreased hardseed content of surface seed by 50% and buried seed by 70%. Surface and buried seeds stored at 25/25�C for 3 months prior to sowing in trays had a total emergence of <10%, compared with 70% emergence for seeds stored at 25/60�C before sowing. These emergence differences reflected their levels of hardseededness. Numbers of seeds recovered from the soil were not significantly different among lines, declining from about 4200 seeds/m2 after initial seed set to 150 seeds/m2 by the following winter, a 97% decrease. Seed production in the second year increased seed reserves to about 8730 seeds/m2. With no further seed production, levels had declined by 93% in June 1990 and by 99% in May 1991. These data confirm the importance of annual seed production for persistence. Total seedling emergence in summer-autumn accounted for only 10% of the estimated seed production in each year. Seedling survival in summer-autumn 1988-89 was 92.7%, more than double the survival in 1989-90. The effect of sowing time on flowering was always significant, with time to first flower being highest (196 days) for the earliest sowing in March (P<0.05), progressively decreasing (P<0.05) to 108 days for the latest sowing in July. In March, April and May sowings, inflorescence numbers on the first day of flowering were similar at about 120/m2, but increased markedly (P<0.05) for sowing in June or July. However, for the March and July sowings, number of inflorescences at the 9 November 1990 count, were lowest (P<0.05). May or June sowings had the highest number of burrs and seeds (P<0.05), indicating that these may be the best sowing times for maximum seed production in these Trifolium subterraneum var. brachycalycinum lines.


Weed Science ◽  
1990 ◽  
Vol 38 (4-5) ◽  
pp. 374-378 ◽  
Author(s):  
Jill Schroeder ◽  
Clyde C. Dowler ◽  
James R. Stansell

The effect of soil matric potential from −0.02 to <–1.5 MPa on Texas panicum growth in drainage lysimeters covered by an automatic rainfall shelter was measured in 1984, 1985, and 1986. Rate of tiller production was faster for plants established in April than June in 1984 and 1985, but not 1986. In 1985 and 1986, dry weight was greater, but total seed production was less for plants established in April than June. Irrigation when the soil matric potential was −0.02, −0.075, or −1.5 MPa did not affect rate of tiller production in 1984. Irrigation when the soil matric potential was −1.5 MPa decreased dry weight of plants but increased seed number per panicle compared to irrigation when the soil matric potential was −0.02 MPa in 1985 and 1986. Plants grown in lysimeters irrigated at soil matric potential <–1.5 MPa in 1985 and 1986 did not wilt at 8:00 a.m.; therefore, they were not watered after establishment. These nonirrigated plants averaged 0.9 and 0.4 kg dry weight and produced 92 200 and 16 100 seeds in 1985 and 1986, respectively.


1992 ◽  
Vol 124 (4) ◽  
pp. 631-636 ◽  
Author(s):  
A.S. McClay

AbstractImpact of the flower- and shoot-tip-feeding beetle, Brachypterolus pulicarius (L.), on growth, flowering, and seed production of common toadflax, Linaria vulgaris (L.) Mill., was investigated using potted plants. Brachypterolus pulicarius had no effect on root or shoot biomass of attacked plants. Adult feeding by B. pulicarius delayed onset of flowering by 27 days relative to controls. Flowering of attacked plants was suppressed from mid-June until mid-July, but by mid-August flowering was similar to that of control plants. Total seed weight, individual seed weight, and percentage germination were all reduced significantly on attacked plants, resulting in a 74% reduction in number of viable seeds produced. Brachypterolus pulicarius is univoltine in Alberta, overwintering mainly as pupae.


2014 ◽  
Vol 28 (3) ◽  
pp. 486-493 ◽  
Author(s):  
Michael J. Walsh ◽  
Stephen B. Powles

Seed production of annual weeds persisting through cropping phases replenishes/establishes viable seed banks from which these weeds will continue to interfere with crop production. Harvest weed seed control (HWSC) systems are now viewed as an effective means of interrupting this process by targeting mature weed seed, preventing seed bank inputs. However, the efficacy of these systems is directly related to the proportion of total seed production that the targeted weed species retains (seed retention) at crop maturity. This study determined the seed retention of the four dominant annual weeds of Australian cropping systems - annual ryegrass, wild radish, brome grass, and wild oat. Beginning at the first opportunity for wheat harvest and on a weekly basis for 28 d afterwards the proportion of total seed production retained above a 15 cm harvest cutting height was determined for these weed species present in wheat crops at nine locations across the Western Australian (WA) wheat-belt. Very high proportions of total seed production were retained at wheat crop maturity for annual ryegrass (85%), wild radish (99%), brome grass (77%), and wild oat (84%). Importantly, seed retention remained high for annual ryegrass and wild radish throughout the 28 d harvest period. At the end of this period, 63 and 79% of total seed production for annual ryegrass and wild radish respectively, was retained above harvest cutting height. However, seed retention for brome grass (41%) and wild oat (39%) was substantially lower after 28 d. High seed retention at crop maturity, as identified here, clearly indicates the potential for HWSC systems to reduce seed bank replenishment and diminish subsequent crop interference by the four most problematic species of Australian crops.


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