Shortest Day Research Articles

Lunar cycles influence the diving behavior and habitat use of short-finned pilot whales around the main Hawaiian Islands

The availability of light, both solar and lunar, is likely to influence the behavior of vertically migrating aquatic animals and their predators. However, the influence of light level on the diving behavior and habitat use of deep-diving cetaceans is not well understood. We used data from 28 depth-transmitting satellite tags deployed on short-finned pilot whales Globicephala macrorhynchus around the main Hawaiian Islands to examine movements and diving behavior in relation to lunar cycles and oceanographic season. During a full moon, dives were deeper (48.1%) and longer (16.7%) than during a new moon. This change appeared to be driven primarily by an increase (25.2%) in the depth of deep dives (>200 m) completed at night and an increase in the proportion of deeper daytime and twilight dives during a full moon. Dives occurred a mean of 18.3 km farther offshore (more than twice as far from shore) during a full moon compared to a new moon. During the oceanographic season with the shortest day length (fall), dives were shallower (25.4%) and shorter (14.2%) than seasons with longer days (summer). This suggests that changes in light level, both solar and lunar, affect the depth of prey targeted by pilot whales, which in turn influences pilot whale diving behavior and distribution. Future research should determine how these changes influence the feeding success and energetics of pilot whales.

Different as night and day: Behavioural and life history responses to varied photoperiods in Daphnia magna.

Nearly all animal species have utilized photoperiod to cue seasonal behaviours and life history traits. We investigated photoperiod responses in keystone species, Daphnia magna, to identify molecular processes underlying ecologically important behaviours and traits using functional transcriptomic analyses. Daphnia magna were photoperiod‐entrained immediately posthatch to a standard control photoperiod of 16 light/ 8 dark hours (16L:8D) relative to shorter (4L:20D, 8L:16D, 12L:12L) and longer (20L:4D) day length photoperiods. Short‐day photoperiods induced significantly increased light‐avoidance behaviours relative to controls. Correspondingly, significant differential transcript expression for genes involved in glutamate signalling was observed, a critical signalling pathway in arthropod light‐avoidance behaviour. Additionally, period circadian protein and proteins coding F‐box/LRR‐repeat domains were differentially expressed which are recognized to establish circadian rhythms in arthropods. Indicators of metabolic rate increased in short‐day photoperiods which corresponded with broadscale changes in transcriptional expression across system‐level energy metabolism pathways. The most striking observations included significantly decreased neonate production at the shortest day length photoperiod (4L:20D) and significantly increased male production across short‐day and equinox photoperiods (4L:20D, 8L:16D and 12L:12D). Transcriptional expression consistent with putative mechanisms of male production was observed including photoperiod‐dependent expression of transformer‐2 sex‐determining protein and small nuclear ribonucleoprotein particles (snRNPs) which control splice variant expression for genes like transformer. Finally, increased transcriptional expression of glutamate has also been shown to induce male production in Daphnia pulex via photoperiod‐sensitive mechanisms. Overall, photoperiod entrainment affected molecular pathways that underpin critical behavioural and life history traits in D. magna providing fundamental insights into biological responses to this primary environmental cue.

Emergence rate of seedlings from hard okra seed coats and seedling growth of some genotypes of West African okra (Abelmoschus caillei)

Abstract. In 2017 and 2018 cropping season, field experiment was conducted at the Food and Agricultural Organization and Tree Crop Plantation, Department of Crop Science, Adamawa State University, Mubi using fifteen genotypes of West African okra. The study was undertaken to study the emergence rate of seedlings from hard okra seed coats, seedling growth and their development. The seeds of the genotypes were soaked in NaCl solution for 24 hours to accelerate the breaking of seed dormancy and to ease seed germination. Tough seed coat usually impairs seed germination by establishing a permeability barrier which can interrupt water uptake required for imbibition, radicle and seedling emergence. The combined analysis results revealed a highly significant (P≤0.01) difference among these genotypes with respect to days to first and 50% flowering including days to first harvest. Furthermore, accession 3 (NG/SA/DEC/07/0448) and accession 11 (Yar kwadon) flowered earlier, had shortest days to first harvest, recorded the highest number of seedlings and emergence percentage than the other genotypes studied.

Agro-morphological Variation in 71 Traditional Rice Cultivars in Sri Lanka

Traditional rice cultivars in Sri Lanka have diverse characteristics that prove the excellent potential for utilizing them for varietal improvement. Seventy-one Sri Lankan traditional rice cultivars obtained from Plant Genetic Resources Center, Gannoruwa, Sri Lanka were used for diversity analysis. Data were collected in the middle-row-plants of each replicate and altogether 80 plants were evaluated in four replicates of each cultivar. Data were collected on 11 parameters in two consecutive Maha seasons in 2012-2014. According to the standard evaluation system of international rice research institute, 67% rice cultivars were tall, and 66% were low tillering. There was no any rice cultivar with high and good reproductive tillers/plant. Around 55% rice cultivars were partially sterile and 43% were fertile. The shortest days to maturity was recorded in Gonabaru (62 days) and the longest days to maturity was recorded in Vellainellu (105 days).
 The variation of agro-morphological characteristics was broad in studied rice cultivars: The recorded highest yield was 22.74 g/plant while the lowest was 1.55 g/plant. The hundred-grain-weight ranged from 3.49-1.27 g and the plant height ranged from 95-192 cm. The recorded highest number of total tillers per plant was 10 and the lowest was 3. Panicle length and panicle weight were ranged from 13-32 cm and 0.36-4.69 g consecutively. The smallest grains were in Herath and the largest grains were in Mudaliwi. The heaviest above ground biomass was achieved by Kallurundoivellai and its harvest index was the least (0.09). The highest filled grain percentage (91.48%) was recorded by Galpa Wee.
 The correlation analysis revealed that the yield per plant was significantly correlated with panicle weight, the total number of spikelets/panicle and number of fertile spikelets/panicle. There was no correlation between panicle length and the final yield of rice though panicle length was correlated with plant height and panicle weight. Total number of spikelets/panicle, the number of fertile spikelets/panicle, and plant height were significantly correlated with panicle weight. None of the parameters were correlated with hundred grain weight. Total biomass was correlated with plant height, the total number of spikelets, and fertile spikelets per panicle. There was no significant correlation between the biomass of rice with the final yield, however, a number of fertile tillers were correlated with a number of total tillers.
 Eleven parameters were sorted into four principal components that explained 87.44% of total variance and cluster analysis categorized the rice cultivars into six clusters at rescaled cluster distance 10 in Ward's linkage analysis.

Response of Head Cabbage (Brassica Oleracea L.) to Different Rates of Inorganic Nitrogen Fertilizer and Farmyard Manure at Bore, Southern Oromia, Ethiopia

Cabbage (Brassica oleracea L.) is the second most important vegetable crop in Ethiopia in area coverage as well as level of production next to red pepper. However, yield of the crop is often constrained by low and imbalanced nutrient supply. This study was conducted at the Bore Agricultural Research Center (BoARC) during the main cropping season to assess the response of N and FYM on growth and yield of cabbage. The treatments consisted of factorial combinations of five levels of N (0, 59,119, 235 and 294 kg N ha -1 ) and four levels of FYM (0, 3, 6 and 10 t ha -1 ) and were laid out in RCBD with three replications. The ANOVA results showed that interaction effect of N and FYM significantly (P<0.001) difference on plant height, number of expanded leaves, days to head initiation, days to 90% maturity, head height, head diameter, untrimmed head weight, trimmed head weight, yield with and without wrapper and biomass of yield. There was a Significance differences between the mean plant heights (43.2cm) of head cabbage observed versus FYM of (10 t ha -1 ) with each level of N (235 kg ha -1 ) for plant height. However, the combined effect of highest N (294 kg ha -1 ) and highest FYM (10 t ha -1 ) recorded maximum number of leaves (16.66), shortest days to head initiation (63.33) and early days to maturity (112). And also the interaction effect of both N and FYM (235 kg + 6 t ha-1), respectively was highly significantly (P<0.001) recorded highest head height (18.14cm), highest head diameter (17.03cm), highest untrimmed head weight (2296.67g), highest trimmed head weight (1766.67g), maximum (107.47 t ha -1 ) yield with wrapper head cabbage, highest head yield without wrapper (72.36 t ha -1 ) and maximum biomass yield (107.47 t ha -1 ) of head cabbage. There was an increasing trend in the yield without wrapper or marketable head yield parameter with the increasing in the rate till combined application of 235 kg N ha -1 from UREA and 6 t FYM ha -1 , but the yield declined above these combinations. Based on partial budget analysis the highest net benefit was obtained from treatment combinations of 235 kg N ha -1 with 6 t ha -1 with a marginal rate of return 2535.31%. The most attractive rates for the producers with low cost of production and higher benefits in this case were treatment combination of 235 kg N ha -1 with 6 t ha -1 . Generally results of the study suggested that head cabbage responded well to the combined application of N and FYM and application of 235 kg N ha -1 + 6 t FYM ha -1 can give optimum cabbage head yield in the study area. Keywords : FYM, N, Thomas F1, Trimmed Head, Untrimmed Head, Yield with Wrapper, Yield without Wrapper DOI : 10.7176/JAAS/52-03

Cycles

Cycles Elizabeth Bevilacqua (bio) The question I always come back to is the date. Does it mean anything that these things all happened on December 21? In 1948, my father and his twin brother were born. In 1990, my dad’s sister woke to her house on fire and by the time the sun had set, her husband and three of her children were dead. And in 2007, my grandfather died hours after my father and I visited him. It is the winter solstice. The shortest day of the year. But the day is not actually any shorter. All 24 hours are there, it’s just that most of them are dark. My aunt says she thinks of the date as a portal that opens up for kinds of passage. She’s Catholic with a tinge of the mystical. After the fire, my father and I drove three hours to the hospital in New Haven every weekend and stayed at the Ronald McDonald House while my one cousin who survived—a girl, my age, my friend (my double)—got skin grafts to mend the burn on her back and huffed into a plastic tube to make three balls of varied shades of blue rise in their distinct columns of air. Still today she has a cough that overtakes her at times. In the hospital, we made earrings and made fun of the nurses. Then, my aunt and cousin lived with us. We had a finished attic that made for two bedrooms. My aunt would look at me and her face would go red, crumple, and dissolve. I would hug her and say nothing. My family, with four kids the same age as her own, must have been an excruciating haunting. Dad said if it were not for my cousin, my aunt would take a long swim in the ocean and never come back. All my cousin’s clothes had burned, and Dad took me to the mall to choose new ones for her. She’d always been a tomboy in rugby shirts and khakis. I [End Page 188] tried to pick things I thought she’d like. I taught her how to peg her pants and to double-layer her socks and scrunch them down. Once, Dad brought home a bouquet of flowers for her and I was unbearably jealous. I began to sneak into her room and steal bras from her drawer. “Training bras.” What were we training for? Perhaps I did not want her to grow up, grow boobs, outgrow the rugby shirts. Perhaps I did not want to grow into a woman with a family to lose. Perhaps I was jealous of my father’s attention. I snatched that symbol from her and hid them in my own chest of drawers. A few years later, when we hit womanhood, terrified of my body’s thickening, its capacity for hunger and life-bearing, I denied all of it as best I could. I’ve been outpacing this a long time. Trying always to keep moving lest it catch up with me. Not the pain of loss—the grief is elemental and plain; I mourn plainly my uncle, my cousins, their short lives, their phantom friendships—but the other tangle, the fear of loss and the true and horrifying uncertainty of life. My aunt says there’s no sense in trying to control things because, as we know, you can’t account for accidents. I’ve spent a long time trying to understand how you could go to bed one night—the longest night of the year—and wake up hours later to your house in flames and your husband and three of your children dead. Seemed someone was owed an explanation. These portals, as my aunt calls them, rings of time that orbit one another and occasionally conjoin to open a small fissure through which someone could make the passage from one to another, are the reason I’ve always wanted to live lightly. To live light, to be light, without excess of body, or possessions, or attachments. So that, should I glimpse the opening, I’ll be ready. I heard things about what happened that night and...

Shoot-root traits of broccoli (Brassica oleracea var. italica L.) as influenced by different irrigation schedules

Frequency of irrigation to the crops is the key factor for proper growth and economic yield. Therefore, in the current study growth of broccoli plants was investigated under different irrigation levels in pot culture condition. Five levels of irrigation schedules were applied including I0 [Non-irrigation control], I1 [Irrigation up to 15 days after transplanting (DAT)], I2 [Irrigation up to 30 DAT], I3 [Irrigation up to 45 DAT] and I4 [Irrigation up to 60 DAT] with three replications. Maximum plant height, shortest days to curd initiation, fresh mass of curd, curd diameter, shoot fresh mass and moisture content of roots per plant were obtained from irrigation up to 60 DAT. Moreover, maximum number of leaves, leaf fresh mass, moisture content, root length, root fresh and dry mass per plant were obtained from irrigation up to 45 DAT while the lowest results were obtained from non-irrigated control treatment. Higher dry weight (3.37 g plant-1) and dry matter content of leaves (11.76%) and roots (18.94%) and root to shoot ratio (0.077) were observed from non-irrigated control treatment. Results suggested that irrigation up to 60 DAT might be optimum schedule for broccoli, but in terms of economic profitability, irrigation up to 45 DAT would be sufficient.

Evaluation of Tomato (Solanum lycopersicum L.) Genotypes for Horticultural Characteristics on the Upland in Southern Sierra Leone

Notwithstanding the importance of tomato in human diet, the average yield of the crop in Africa hardily exceeds 7.5 tha-1. There is continuous unavailability of high yielding cultivars that are adapted to diverse environment and suitable for different purposes. Consequently, evaluation of introduced tomato genotypes for desired horticultural characteristics to identify superior genotypes for additional improvement in yield and yield related traits is indispensible. Hence eight tomato (Solanum lycopersicum L.) genotypes including parental were field planted in a randomized complete block design with three replications at the Department of Horticulture Nursery Unit, School of Natural resources Management, Njala University, Njala Campus, Moyamba District, Southern Sierra Leone to evaluate them for good horticultural traits. Data collected include plant height at 50% and 100% flowering, stem girth at 50% and 100% flowering, days to first, 50% and 100% flowering, days to maturity, number of fruits set per plant, number of fruits harvested per plant, average fruit weights, fruit length, fruit diameter, fruit flesh thickness, locule number, marketable and nonmarketable fruits per plant. Results from the study indicated that all genotypes studied are adaptable to the Sierra Leone climatic conditions. P1 (097) recorded the highest number of fruits set per plant, number of fruits harvested per plant and tallest and largest plant height and stem girth at 100% flowering. BC2F2 had the highest locule number while R3P9 had the heaviest fruit weight. P2 (213) had the thickest fruit flesh thickness and longest duration to fruit maturity respectively while P1 (097), BC1F2 and R3P9 had the same number of shortest days to maturity. Regarding fruit length and diameter, R3P8 and R6P6 had the longest and widest. With respects to marketable and nonmarketable fruit per plant, P1 (097) recorded the highest correspondingly.

Cold acclimation in warmer extended autumns impairs freezing tolerance of perennial ryegrass (Lolium perenne) and timothy (Phleum pratense).

The effect of variable autumn temperatures in combination with decreasing irradiance and daylength on photosynthesis, growth cessation and freezing tolerance was investigated in northern- and southern-adapted populations of perennial ryegrass (Lolium perenne) and timothy (Phleum pratense) intended for use in regions at northern high latitudes. Plants were subjected to three different acclimation temperatures; 12, 6 and 9/3°C (day/night) for 4 weeks, followed by 1 week of cold acclimation at 2°C under natural light conditions. This experimental setup was repeated at three different periods during autumn with decreasing sums of irradiance and daylengths. Photoacclimation, leaf elongation and freezing tolerance were studied. The results showed that plants cold acclimated during the period with lowest irradiance and shortest day had lowest freezing tolerance, lowest photosynthetic activity, longest leaves and least biomass production. Higher acclimation temperature (12°C) resulted in lower freezing tolerance, lower photosynthetic activity, faster leaf elongation rate and higher biomass compared with the other temperatures. Photochemical mechanisms were predominant in photoacclimation. The northern-adapted populations had a better freezing tolerance than the southern-adapted except when grown during the late autumn period and at the highest temperature; then there were no differences between the populations. Our results indicate that the projected climate change in the north may reduce freezing tolerance in grasses as acclimation will take place at higher temperatures and shorter daylengths with lower irradiance.

Influence of inoculation method and spawn level on biological efficiency of &lt;i&gt;Pleurotus ostreatus&lt;/i&gt;

Pleurotus ostreatus , an edible mushroom cultivated worldwide and appreciated due to its exotic taste and nutritional value. Spawning rate and method of spawn application are crucial factors influencing mushroom growth and yield. The objective of this work was to determine the effect of spawn quantity and spawning techniques on the growth and yield of P. ostreatus . It investigated the use of different spawning methods (on-spot, top and bottom, mixin and layering) and spawn levels (3, 5, 7, 9, 11, and 13%) on the mushroom. The results obtained showed that as the spawn level increased, growth and yield parameters also increased. The highest number of fruits (11.33), fruit weight (65.69g), widest pileus (657cm.) and longest stipe (5.53cm) were observed at 13% spawn level and least in others. The densest mycelia were obtained as from 9% spawn levels; the mean fruit weight was highest (7.56g) at 9%. Significantly shortest days to substrate colonization and primodia initiation were observed at 13% spawn level and the longest at 3%. The results for spawning methods indicated highest biological efficiency (62.57%) when spawn was applied at both ends of the bag while the least was on the on-spot application. Days to substrate colonization and initiation of the mushroom primodia were shorter significantly at p< 0.05. This findings implied that when sufficient amount of spawn is added to a fruiting substrate and applied bi-directionally, the mycelium grows faster and has more energy available for fruiting body formation, hence the increased yield and better biological efficiency. Keywords: Spawning method, spawn level, Pleurotus ostreatus , biological efficiency

Love's Intermedial Limbecke: A Stylistic Analysis of Donne's “A Nocturnall upon S. Lucies Day, Being the Shortest Day”

ABSTRACTJohn Donne's “A Nocturnall upon S. Lucies Day, Being the Shortest Day” is a complex engagement with alchemy that many critics have found difficult to decode. The stylistic approach taken in this article examines the use of alchemy as a source domain at all levels of the poem. The conceptual metaphor Love is a Force is shown to have multi-planar expression. Graphologically, this renders “Nocturnall” a pattern poem, the stanzaic form of which resembles a limbecke (distillatory vessel). This intermediality is complemented by interlocking instantiations of the trope at the level of lexis, grammar and phonology.

Relationship between the pre- and postpartum body condition scores and periparturient indices and fertility in high-yielding dairy cows

Abstract Introduction: The aim of this study was to investigate the relationship between body condition score (BCS) determined on the dry-off day, calving day, and in the first month of lactation, its changes during the dry period and early lactation, and periparturient indices and fertility in high-producing dairy cows. Material and Methods: The experiment was conducted in two herds: A and B, located in Western Poland. The studies were conducted on 116 and 108 Polish Holstein-Friesian dairy cows respectively, with an average milk yield of &gt;10 000 kg/305-day lactation. The experiment included the dry period (-56 d to the calving day), the calving day, and early lactation (from +1 to +56 d). The experimental factor was BCS (0 to 5-point scale). The BCS was performed by one person on day -56, on parturition day (in the first 12 h after calving) and on day 30 of lactation. Results: A decrease in BCS (≥-0.25) in herd A during the dry period accelerated the planned calving period by 7.3 d. In the group of cows with BCS &lt;3.25 on the dry-off day, the lowest artificial insemination index (1.80), the shortest period of insemination services (25 d), and days open (87 d) were recorded. Moreover, cows with BCS &lt; 3.25 at calving had the shortest days open (91 d). BCS &gt;3.50 in the first month of lactation (30 d) resulted in the extension of uterine involution period (56 d). Improvement of BCS during the dry period shortened the anoestrus (60 d) in herd A and the period of insemination service (60 d) in herd B. However, in this group (IM BCS ≥ 0.25) of cows the day of the highest artificial insemination index (2.50) in herd B was analysed. Conclusion: The body condition on the dry-off day and at calving, as well as its deterioration in the first month of lactation, have a considerable effect on fertility indices in dairy cows, thus confirming the advisability of its regular monitoring during routine operations connected with the management of a dairy cattle herd.

Circadian rhythm of calciotropic hormones, serum calcium, phosphorus and magnesium during the shortest and longest days of the year in horses in New Zealand.

A study was conducted to determine the circadian rhythms and trends of vitamin D metabolites including 25-hydroxyvitamin D3 , 25-hydroxyvitamin D2 , 1,25-dihydroxyvitamin D and parathyroid hormone, in addition to serum calcium, phosphorus and magnesium concentrations in horses over 48h on the shortest and longest days of the year in 2013. Five healthy adult horses (Equus caballus) were on a constant pasture feeding regimen, and blood samples were collected from each horse every 3h over a 48-h period, starting at 07:00PM on day one and finishing at 07:00PM on day three, for the measurement of calciotropic hormones and electrolytes. There was a significant difference between the serum concentration of calciotropic hormones, iCa, tCa, P and tMg between the shortest (winter) and longest (summer) days of the year in horses. Serum concentration of 25OHD3 was very low and mostly undetectable. Serum iCa, 1,25(OH)2 D and PTH concentrations clearly showed a circadian rhythm on the longest days of the year and serum tCa, P and tMg concentrations showed a diurnal pattern on the longest days (summer) of the year. None of the analytes showed any circadian rhythm on the shortest days (winter) of the year. The result of this study could have significant relevance to equine athletes travelling to international equestrian competitions and facing a huge time and seasonal differences that might affect their ability to adjust their circadian rhythms to new time zones.

Effects of Compost and Inorganic NP Rates on Growth, Yield and Yield Components of Teff (Eragrotis teff (Zucc.) Trotter) in Girar Jarso District, Central Highland of Ethiopia

Teff is the major crop produced in study area whose productivity is being affected by low soil fertility and organic matter depletion. Hence, an experiment, having factorial combination of 0, 2.5, 5 and 7.5 t ha-1 of compost and 0/0, 16/11.5, 32/23 and 64/46 kg ha-1 of N/P2O5, was conducted in 2014/15 main cropping season to assess the effect of rates of compost and NP fertilizers on growth, yield and yield components of teff and to determine their economical rates. Treatments were laid out in RCBD in three replications. The results indicated that the main effect of compost rate significantly increased dry biomass and straw yield and decreased harvest index. Except on number of productive tillers, the main effect of NP fertilizer was significant on all the parameters measured. The shortest days to heading, highest; lodging percentage, plant height, panicle length and dry biomass were recorded at 64/46 kg ha-1 of N/P2O5, all showing increasing trend with increasing NP. The highest grain and straw yield and net farm benefit were recorded at interaction of 64/46 N/P2O5 kg ha-1 and 7.5 tons ha-1 of compost. Generally, the study suggested that, the use full dose of nationally blanket recommended NP rate (64/48 kg of N/ P2O5) with 7.5 tons ha-1 of compost is likely combination to attain the optimum grain yield and profit and can be alternative approach for integrated soil fertility management measure instead of the sole application of inorganic fertilizers.

Leaf appearance of annual clovers responds to photoperiod at emergence

Abstract Leaf appearance rate and time to canopy expansion of four annual clover species (arrowleaf, balansa, gland and Persian) were quantified in field and controlled environment studies. Crops sown in autumn, which experienced shortening daylengths at emergence, had a slower rate of leaf production and consequently took a longer time to initiate branching, than spring-sown crops. When autumn-sown ‘Bolta’ balansa clover emerged on the shortest day in winter (21 June), the rate of leaf appearance was lengthened by 4 °C d/leaf/h. When the same species emerged after the shortest day, into an increasing photoperiod, the phyllochron was shortened by 5 °C d/leaf/h. This influence of photoperiod on the phyllochron consequently altered the time to axillary leaf production (branching). Throughout all sowing dates, phyllochron was the fastest for ‘Prima’ gland (33–91 °C d/leaf) and slowest for ‘Cefalu’ arrowleaf (53–116 °C d/leaf) clovers. ‘Bolta’ balansa was 44–82 °C d/leaf and ‘Mihi’ Persian 61–93 °C d/leaf. The response of phyllochron to photoperiod suggests these annual clovers should be sown in late summer or early autumn to initiate axillary leaf production as soon as possible to ensure maximize dry matter for early spring.

Influence of Sowing Depth and Shade on Emergence and Seedling Growth of Centrosema pubescens

Depth of sowing and shade levels were two ecological factors affecting early establishment of a plant. The effects of sowing depths of seeds and shade on seedling emergence, morphological traits and seedling biomass of Centrosema pubescens were examined. The seeds were sown at the depth of 2, 4, 6 and 8 cm and shaded at levels of 0 (full sunlight) and 50%. Analysis of variance showed a significant effect (P<0.05) of sowing depth on seedling performances. Sowing at the depth of 2 cm produced the highest percentage of seedling emergence, the shortest days to emergence, the biggest seedling diameter and the greatest seedling biomass. Shade significantly (P<0.05) increased seedling height and shootroot dry weight ratio. The findings indicate that for improved growth and dry matter yield, Centrosema pubescens seeds should be sown at a depth of 2 cm.

Melatonin implants do not alter estrogen feedback or advance puberty in gilts

Puberty in pigs is often delayed during late summer and autumn, with long daylength the most likely cause. We hypothesised (1) that gilts born around the shortest day would have a later release from the negative feedback actions of estradiol than gilts born around the spring equinox and (2) melatonin treatment would result in an earlier release from estradiol negative feedback and advance the onset of puberty in gilts born around the spring equinox. We first determined the optimal number of estradiol implants required to monitor the release from estradiol negative feedback in ovariectomised gilts. Secondly we determined whether melatonin implants altered negative feedback in 4 cohorts of ovariectomised gilts born between the winter solstice and spring equinox, and in the following year whether melatonin altered the time of the first ovulation in 5 cohorts of intact gilts born between the winter solstice and spring equinox. Plasma LH and FSH increased between 126 and 210d of age (P<0.001) in each cohort (season), but there was no effect of cohort, melatonin treatment or interactions (P>0.05). Age at first detection of elevated plasma progesterone in untreated, intact gilts decreased across the 4 cohorts (P<0.05). Melatonin treatment of intact gilts failed to advance the age of puberty irrespective of their season of birth (P>0.05). In conclusion, while we confirmed that estradiol sensitivity is decreased as gilts age, we failed to demonstrate any effects of season or melatonin on estradiol feedback or melatonin on puberty.

Study of grain yield and several morphological traits diversity in some durum wheat genotypes

Durum wheat has been subjected to intense cultivation due to its economic importance and it occupies second place after bread wheat in many regions. The experiment was organized in a randomized complete block design with four replications using thirteen newly improved durum wheat genotypes and one check cultivar as Dehdasht. Several traits including plant height, peduncle length, spike length, growth vigority, agronomic score, days to heading, days to physiological maturity, thousand kernel weight, test weight and grain yield were measured. Significant differences were observed for all the traits among durum wheat genotypes indicating considerable amount of variation. The estimates of the coefficient of variation were high for spike length and growth vigority. The number of days to heading ranged from 106.5 (G1 and G3) to 111.8 (G10) while G13 had the longest (146.0) and G2 (142.5) and G11 (142.3) had the shortest days to physiological maturity. The test weight ranged from 378.5 in G10 to 397.0 in G8, but the check cultivar indicated the highest thousand kernel weight (44.0 g). According to grain yield, G3 had the maximum yield (6720 kg ha-1) and G7 had the minimum yield (5047 kg ha-1). The high yielding genotypes had high values for growth vigority, spike length, peduncle length, agronomic score and thousand kernel weight. The information on the agro-morphological traits of the studied durum wheat genotypes will be helpful to plant breeders in constructing their breeding materials and implementing selection strategies.

Associations between age at first calving, rearing average daily weight gain, herd milk yield and dairy herd production, reproduction, and profitability

The objective of this study was to evaluate the associations of variable intensity in rearing dairy heifers on 33 commercial dairy herds, including 23,008 cows and 18,139 heifers, with age at first calving (AFC), average daily weight gain (ADG), and milk yield (MY) level on reproduction traits and profitability. Milk yield during the production period was analyzed relative to reproduction and economic parameters. Data were collected during a 1-yr period (2011). The farms were located in 12 regions in the Czech Republic. The results show that those herds with more intensive rearing periods had lower conception rates among heifers at first and overall services. The differences in those conception rates between the group with the greatest ADG (≥0.800kg/d) and the group with the least ADG (≤0.699kg/d) were approximately 10 percentage points in favor of the least ADG. All the evaluated reproduction traits differed between AFC groups. Conception at first and overall services (cows) was greatest in herds with AFC ≥800 d. The shortest days open (105 d) and calving interval (396 d) were found in the middle AFC group (799 to 750 d). The highest number of completed lactations (2.67) was observed in the group with latest AFC (≥800 d). The earliest AFC group (≤749 d) was characterized by the highest depreciation costs per cow at 8,275 Czech crowns (US$414), and the highest culling rate for cows of 41%. The most profitable rearing approach was reflected in the middle AFC (799 to 750 d) and middle ADG (0.799 to 0.700kg) groups. The highest MY (≥8,500kg) occurred with the earliest AFC of 780 d. Higher MY led to lower conception rates in cows, but the highest MY group also had the shortest days open (106 d) and a calving interval of 386 d. The same MY group had the highest cow depreciation costs, net profit, and profitability without subsidies of 2.67%. We conclude that achieving low AFC will not always be the most profitable approach, which will depend upon farm-specific herd management. The MY is a very important factor for dairy farm profitability. The group of farms having the highest MY achieved the highest net profit despite having greater fertility problems.

“Darkening the darkness”: Alchemy as Radical Negativity in Donne’s “A Nocturnal upon St. Lucy’s Day, being the shortest day”

“Darkening the darkness”: Alchemy as Radical Negativity in Donne’s “A Nocturnal upon St. Lucy’s Day, being the shortest day”