Responses of Tea (Camellia Sinensis) to Irrigation and Fertilizer. III. Shoot Extension and Development

1993 ◽  
Vol 29 (3) ◽  
pp. 323-339 ◽  
Author(s):  
William Stephens ◽  
M. K. V. Carr
Keyword(s):  
Research Unit ◽  
Dry Season ◽  
Base Temperature ◽  
High Input ◽  
Wet Season ◽  
Stage Of Development ◽  
Wide Range ◽  
Terminal Bud ◽  
Cool Dry Season ◽  
Commercial Harvesting

SUMMARYRates of shoot extension and development (the unfolding of leaves) were recorded in an irrigation × fertilizer experiment on Clone 6/8 at Ngwazi Tea Research Unit in southern Tanzania. The wide range of mean temperatures (from 15–20°C) meant that the duration of the shoot replacement cycle (the time taken for an axillary bud released from apical dominance to develop three leaves and a terminal bud), in fully irrigated tea receiving 450 kg N ha-l, varied from 65 d in the warm wet season to 95 d in the cool dry season, compared with 75 to 180 d for unirrigated and unfertilized tea. Regression analysis indicated that the base temperature for extension, for Clone 6/8 in high-input plots, was about 10°C, some 2–3°C more than that for development. As a result of these differences in base temperature, the length of shoots with three leaves and a bud varied considerably between treatments and seasons, ranging from 15 mm in the unirrigated plots (at the end of the dry season) to 130 mm in the high-input plots at the start of the rains. Shoots from well fertilized tea were always longer (at a given stage of development) than those from unfertilized tea. The results are discussed in terms of the possible mechanisms responsible for the observed responses (changes in partitioning between roots and shoots), commercial harvesting practices and yield modelling.Extensión y desarrollo de broies en el té

scholarly journals Agricultural crops in the diet of bearded capuchin monkeys, Cebus libidinosus Spix (Primates: Cebidae), in forest fragments in southeast Brazil

2008 ◽  
Vol 25 (1) ◽  
pp. 32-39 ◽  
Author(s):  
Carlos Henrique de Freitas ◽  
Eleonore Z. F. Setz ◽  
Alba R. B. Araújo ◽  
Nivar Gobbi
Keyword(s):  
Fruit Production ◽  
Dry Season ◽  
Southeastern Brazil ◽  
Capuchin Monkeys ◽  
Home Ranges ◽  
Forest Fragments ◽  
Wet Season ◽  
Plant Matter ◽  
Wide Range ◽  
Cebus Libidinosus

Capuchin monkeys occupy a wide range of habitats where they feed on fruits, arthropods, and vertebrates. Their large home ranges (80-900 ha) suggest that living in forest fragments may challenge their adaptability. We identified and quantified the main food items of Cebus libidinosus Spix, 1823 in forests fragments (100 ha) in southeastern Brazil. We recorded the feeding activities of two groups using scan sampling over a 13-month period. The diet was composed of fruits, crops, animal prey, seeds, plant matter and undetermined. Fruit was eaten more in the wet season than in the dry season, and maize and sugar cane consumption peaked in the early dry season. The proportion of fruit in the diet was positively correlated with fruiting intensity of zoochorous trees. The plant diet included 54 species, with maize, Rhamnidium elaeocarpus, Acrocomia aculeata, Guazuma ulmifolia and Cariniana, being most important. Although dietary composition and diversity were similar to capuchins in larger forest fragments, feeding on crops attained higher percentages at times when zoochorous fruit production was low in fragments.

Cloud macrophysical properties from airborne observations during EUREC4A

2020 ◽  
Author(s):  
Heike Konow ◽  
Marcus Klingebiel ◽  
Felix Ament
Keyword(s):  
Deep Convection ◽  
Dry Season ◽  
Trade Wind ◽  
Special Focus ◽  
Wet Season ◽  
Diurnal Cycles ◽  
Cloud Radar ◽  
Wide Range ◽  
Macrophysical Properties ◽  
Different Response

<p><span>Trade wind cumulus clouds are the predominant cloud type over the tropical Atlantic east of the island of Barbados. Parameters describing their macroscopic shape can help characterizing and comparing general features of clouds. This characterizing will indirectly help to constrain estimates of climate sensitivity, because models with different structures of trade wind cumuli feature different response to increased CO2 contents.</span></p><p><span>Two aircraft campaigns with the HALO (High Altitude LOng range) aircraft took place in the recent past in this region: NARVAL-South (Next-generation Aircraft Remote-Sensing for VALidation studies) in December 2013, during the dry season, and NARVAL2 in August 2016, during the wet season. During these two campaigns, a wide range of cloud regimes from shallow to deep convection were sampled. This past observations are now extended with observations from this year’s measurement campaign EUREC<sup>4</sup>A, again during the dry season. EUREC<sup>4</sup>A is endorsed as WCRP capstone experiment and the synergy of four research aircraft, four research vessels and numerous additional observations will provide comprehensive characterizations of trade wind clouds and their environment.</span></p><p><span>Part of the NARVAL payload on HALO is a 35 GHz cloud radar, which has been deployed on HALO on several missions since 2013. These cloud radar measurements are used to segment individual clouds entities by applying connected component analysis to the radar cloud mask. From these segmented individual clouds, macrophysical parameters are derived to characterize each individual cloud. </span></p><p><span>This presentation will give an overview of the cloud macrophysics observed from HALO during EUREC<sup>4</sup>A. Typical macrophysical parameters, i.e. cloud depth, cloud length, cloud fraction, are analyzed. We will relate these to observations from past campaigns and assess the representativeness of EUREC<sup>4</sup>A. As special focus of the EUREC<sup>4</sup>A campaign, measurements will be performed during different times of the day to detect diurnal cycles. Macrophysical parameters can be used to characterize changes over the day and cloud scenes of similar clouds types can be identified.</span></p>

scholarly journals Yields of Organically Grown Sweet Pepper Cultivars and Lines during the Hot-wet and Cool-dry Season in the Tropics

2009 ◽  
Vol 19 (2) ◽  
pp. 418-422 ◽  
Author(s):  
Peter Juroszek ◽  
Hsing-Hua Tsai
Keyword(s):  
Organic Farming ◽  
Farming Systems ◽  
Sweet Pepper ◽  
Dry Season ◽  
Viable Alternative ◽  
Conventional Farming ◽  
Wet Season ◽  
Commercial Cultivars ◽  
The Tropics ◽  
Cool Dry Season

Organic production is considered by many researchers to be a viable alternative to conventional farming systems. Equivalent yields already have been demonstrated in several studies. The major objective of our study was to collect data on total and marketable fruit yields of sweet pepper (Capsicum annuum) under organic farming conditions in the tropics. Experiments were conducted during the hot-wet season from 7 Mar. 2007 to 30 July 2007 and during the cool-dry season from 27 Nov. 2007 to 7 Apr. 2008. The six experimental entries included four commercial F1 hybrids and two genotypes bred at AVRDC–The World Vegetable Center (Shanhua, Taiwan). During the hot-wet season, high total (44.6–55.7 t·ha−1) and marketable yields (36.9–45.6 t·ha−1) were achieved under organic farming conditions in the open field similar to yields of conventionally produced sweet pepper in previous field experiments at AVRDC. The total yield of the commercial cultivars Queen Star and Hercules exceeded 50 t·ha−1; however, this was not significantly different compared with the other trial entries. During the cool-dry season, the total (25.4–45.7 t·ha−1) and marketable yields (21.1–37.8 t·ha−1) of all trial entries were reduced, probably because the relatively late planting date in November and relatively low air temperature resulted in reduced fruit set. The commercial cultivars Andalus and Green Bell Improved realized in both seasons a total fruit yield of more than 40.0 t·ha−1, suggesting that these can be grown successfully in hot-wet and cool-dry seasons. The relatively high yields of sweet pepper achieved on-station under tropical climatic conditions may encourage farmers and agricultural stakeholders to consider organic farming approaches as a viable alternative to conventional farming systems.

scholarly journals Mental healthcare in Laos

2007 ◽  
Vol 4 (4) ◽  
pp. 90-92 ◽  
Author(s):  
Ken Courtenay ◽  
Chantharavady Choulamany
Keyword(s):  
East Asia ◽  
Democratic Republic ◽  
Mental Healthcare ◽  
Dry Season ◽  
South East Asia ◽  
Diverse Population ◽  
Wet Season ◽  
French Colonies ◽  
Travel Industry ◽  
Cool Dry Season

Laos (officially the Lao People's Democratic Republic) is a land-locked country in South East Asia, and one of the three former French colonies of Indochina. Since 1989, when it was opened to foreigners, there has been an influx of non-governmental organisations (NGOs) and tourists. From 1998 tourist numbers have increased every year, and Laos has become the ‘must see’ destination in a travel industry that craves the exotic. It has an old and rich culture with a diverse population. The climate is tropical, with a cool dry season and a hot wet season, when temperatures reach 38°C.

scholarly journals Total OH reactivity over the Amazon rainforest: variability with temperature, wind, rain, altitude, time of day, season, and an overall budget closure

2021 ◽  
Vol 21 (8) ◽  
pp. 6231-6256
Author(s):  
Eva Y. Pfannerstill ◽  
Nina G. Reijrink ◽  
Achim Edtbauer ◽  
Akima Ringsdorf ◽  
Nora Zannoni ◽  
...  
Keyword(s):  
Tropical Forests ◽  
Time Of Day ◽  
Green Leaf Volatiles ◽  
Dry Season ◽  
Amazon Forest ◽  
Wet Season ◽  
Leaf Volatiles ◽  
Transition Season ◽  
Wide Range ◽  
Volatile Organic

Abstract. The tropical forests are Earth's largest source of biogenic volatile organic compounds (BVOCs) and thus also the largest atmospheric sink region for the hydroxyl radical (OH). However, the OH sink above tropical forests is poorly understood, as past studies have revealed large unattributed fractions of total OH reactivity. We present the first total OH reactivity and volatile organic compound (VOC) measurements made at the Amazon Tall Tower Observatory (ATTO) at 80, 150, and 320 m above ground level, covering two dry seasons, one wet season, and one transition season in 2018–2019. By considering a wide range of previously unaccounted for VOCs, which we identified by proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS), the unattributed fraction was with an overall average of 19 % within the measurement uncertainty of ∼ 35 %. In terms of seasonal average OH reactivity, isoprene accounted for 23 %–43 % of the total and oxygenated VOCs (OVOCs) for 22 %–40 %, while monoterpenes, sesquiterpenes, and green leaf volatiles combined were responsible for 9 %–14 %. These findings show that OVOCs were until now an underestimated contributor to the OH sink above the Amazon forest. By day, total OH reactivity decreased towards higher altitudes with strongest vertical gradients observed around noon during the dry season (−0.026 s−1 m−1), while the gradient was inverted at night. Seasonal differences in total OH reactivity were observed, with the lowest daytime average and standard deviation of 19.9 ± 6.2 s−1 during a wet–dry transition season with frequent precipitation; 23.7 ± 6.5 s−1 during the wet season; and the highest average OH reactivities during two dry-season observation periods with 28.1 ± 7.9 s−1 and 29.1 ± 10.8 s−1, respectively. The effects of different environmental parameters on the OH sink were investigated, and quantified, where possible. Precipitation caused short-term spikes in total OH reactivity, which were followed by below-normal OH reactivity for several hours. Biomass burning increased total OH reactivity by 2.7 to 9.5 s−1. We present a temperature-dependent parameterization of OH reactivity that could be applied in future models of the OH sink to further reduce our knowledge gaps in tropical-forest OH chemistry.

scholarly journals Seasonal changes in the reproductive performance in local cows receiving artificial insemination in the Pursat province of Cambodia

2020 ◽  
Vol 33 (12) ◽  
pp. 1922-1929
Author(s):  
Bengthay Tep ◽  
Yasuhiro Morita ◽  
Shuichi Matsuyama ◽  
Satoshi Ohkura ◽  
Naoko Inoue ◽  
...  
Keyword(s):  
Body Condition ◽  
Reproductive Performance ◽  
Artificial Insemination ◽  
Seasonal Changes ◽  
Dry Season ◽  
Ambient Conditions ◽  
Wet Season ◽  
Tropical Country ◽  
Calving Rate ◽  
Cool Dry Season

Objective: The present study aimed to survey seasonal changes in reproductive performance of local cows receiving artificial insemination (AI) in the Pursat province of Cambodia, a tropical country, to investigate if ambient conditions affect the reproductive performance of cows as to better understand the major problems regarding cattle production.Methods: The number of cows receiving AI, resultant number of calving, and calving rate were analyzed for those receiving the first AI from 2016 to 2017. The year was divided into three seasons: cool/dry (from November to February), hot/dry (from March to June), and wet (from July to October), based on the maximal temperature and rainfall in Pursat, to analyze the relationship between ambient conditions and the reproductive performance of cows. Body condition scores (BCS) and feeding schemes were also analyzed in these seasons.Results: The number of cows receiving AI was significantly higher in the cool/dry season than the wet season. The number of calving and calving rate were significantly higher in cows receiving AI in the cool/dry season compared with the hot/dry and wet seasons. The cows showed higher BCSs in the cool/dry season compared to the hot/dry and wet seasons probably due to the seasonal changes in the feeding schemes: these cows grazed on wild grasses in the cool/dry season but fed with a limited amount of grasses and straw in the hot/dry and wet seasons.Conclusion: The present study suggests that the low number of cows receiving AI, low number of calving, and low calving rate could be mainly due to poor body condition as a result of the poor feeding schemes during the hot/dry and wet seasons. The improvement of body condition by the refinement of feeding schemes may contribute to an increase in the reproductive performance in cows during the hot/dry and wet seasons in Cambodia.

scholarly journals Total OH reactivity over the Amazon rainforest: variability with temperature, wind, rain, altitude, time of day, season, and an overall budget closure

2020 ◽  
Author(s):  
Eva Y. Pfannerstill ◽  
Nina G. Reijrink ◽  
Achim Edtbauer ◽  
Akima Ringsdorf ◽  
Nora Zannoni ◽  
...  
Keyword(s):  
Tropical Forests ◽  
Ground Level ◽  
Time Of Day ◽  
Green Leaf Volatiles ◽  
Dry Season ◽  
Amazon Forest ◽  
Wet Season ◽  
Leaf Volatiles ◽  
Transition Season ◽  
Wide Range

Abstract. The tropical forests are Earth’s largest source of biogenic volatile organic compounds (BVOCs) and thus also the largest atmospheric sink region for the hydroxyl radical (OH). However, the OH sink above tropical forests is poorly understood, as past studies revealed large unattributed fractions of total OH reactivity. We present the first total OH reactivity and VOC measurements made at the Amazon Tall Tower Observatory (ATTO) at 80, 150, and 320 m above ground level, covering two dry seasons, one wet and one transition season in 2018–2019. By considering a wide range of previously unaccounted for VOCs, which we identified by PTR-ToF-MS, the unattributed fraction was with an overall average of 19 % within the measurement uncertainty of ~ 35 %. In terms of seasonal average OH reactivity, isoprene accounted for 23–43 % of the total, oxygenated VOCs (OVOCs) for 22–40 %, while monoterpenes, sesquiterpenes, and green leaf volatiles combined were responsible for 9–14 %. These findings show that OVOCs were until now an underestimated contributor to the OH sink above the Amazon forest. By day, total OH reactivity decreased towards higher altitudes with strongest vertical gradients observed around noon during the dry season (−0.026 s−1 m−1), while the gradient was inverted at night. Seasonal differences in total OH reactivity were observed, with the lowest daytime average and standard deviation of 19.9 ± 6.2 s−1 during a wet–dry transition season with frequent precipitation, 23.7 ± 6.5 s−1 during the wet season, and the highest average OH reactivities during two dry season observation periods with 28.1 ± 7.9 s−1 and 29.1 ± 10.8 s−1, respectively. The effects of different environmental parameters on the OH sink were investigated, and quantified, where possible. Precipitation caused short-term spikes in total OH reactivity, which were followed by below-normal OH reactivity for several hours. Biomass burning increased total OH reactivity by 2.7 s−1 to 9.5 s−1. We present a temperature-dependent parameterization of OH reactivity that could be applied in future models of the OH sink to further reduce our knowledge gaps in tropical forest OH chemistry.

As(III) Removal by Dynamic Adsorption onto Amberlite XAD7 Functionalized with Crown Ether and Doped with Fe(III) Ions

2019 ◽  
Vol 70 (7) ◽  
pp. 2330-2334
Author(s):  
Mihaela Ciopec ◽  
Adina Negrea ◽  
Narcis Duteanu ◽  
Corneliu Mircea Davidescu ◽  
Iosif Hulka ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Arsenic Removal ◽  
Arsenic Concentration ◽  
Fixed Bed ◽  
World Health ◽  
Arsenic Content ◽  
Arsenic Adsorption ◽  
Stage Of Development ◽  
Wide Range ◽  
Health Organization

Arsenic content in groundwater�s present a wide range of concentration, ranging from hundreds of micrograms to thousands of micrograms of arsenic per litter, while the maximum permitted arsenic concentration established by World Health Organization (WHO) is 10 mg L-1. According to the WHO all people, regardless of their stage of development and their social economic condition, have the right to have access to adequate drinking water. The most efficient and economic technique used for arsenic removal is represented by adsorption. In order to make this remediation technique more affordable and environmentally friendly is important to new materials with advance adsorbent properties. Novelty of present paper is represented by the usage of a new adsorbent material obtained by physical - chemical modification of Amberlite XAD polymers using crown ethers followed by iron doping, due to well-known affinity of arsenic for iron ions. Present paper aims to test the obtained modified Amberlite polymer for arsenic removal from real groundwater by using adsorption in a fixed bed column, establishing in this way a mechanism for the adsorption process. During experimental work was studied the influence of competing ions from real water into the arsenic adsorption process.

scholarly journals The seasonal changes of the gut microbiome of the population living in traditional lifestyles are represented by characteristic species-level and functional-level SNP enrichment patterns

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Xue Zhu ◽  
Jiyue Qin ◽  
Chongyang Tan ◽  
Kang Ning
Keyword(s):  
Gut Microbiome ◽  
Seasonal Changes ◽  
Dry Season ◽  
Urban Setting ◽  
Snp Analysis ◽  
Wet Season ◽  
Human Gut ◽  
Human Gut Microbiome ◽  
Genome Level ◽  
Prevalent Species

Abstract Background Most studies investigating human gut microbiome dynamics are conducted on humans living in an urban setting. However, few studies have researched the gut microbiome of the populations living traditional lifestyles. These understudied populations are arguably better subjects in answering human-gut microbiome evolution because of their lower exposure to antibiotics and higher dependence on natural resources. Hadza hunter-gatherers in Tanzania have exhibited high biodiversity and seasonal patterns in their gut microbiome composition at the family level, where some taxa disappear in one season and reappear later. Such seasonal changes have been profiled, but the nucleotide changes remain unexplored at the genome level. Thus, it is still elusive how microbial communities change with seasonal changes at the genome level. Results In this study, we performed a strain-level single nucleotide polymorphism (SNP) analysis on 40 Hadza fecal metagenome samples spanning three seasons. With more SNP presented in the wet season, eight prevalent species have significant SNP enrichment with the increasing number of SNP calling by VarScan2, among which only three species have relatively high abundances. Eighty-three genes have the most SNP distributions between the wet season and dry season. Many of these genes are derived from Ruminococcus obeum, and mainly participated in metabolic pathways including carbon metabolism, pyruvate metabolism, and glycolysis. Conclusions Eight prevalent species have significant SNP enrichments with the increasing number of SNP, among which only Eubacterium biforme, Eubacterium hallii and Ruminococcus obeum have relatively high species abundances. Many genes in the microbiomes also presented characteristic SNP distributions between the wet season and the dry season. This implies that the seasonal changes might indirectly impact the mutation patterns for specific species and functions for the gut microbiome of the population that lives in traditional lifestyles through changing the diet in wet and dry seasons, indicating the role of these variants in these species’ adaptation to the changing environment and diets.

scholarly journals Seasonal Climate Impacts on Vocal Activity in Two Neotropical Nonpasserines

Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 319
Author(s):  
Cristian Pérez-Granados ◽  
Karl-L. Schuchmann
Keyword(s):  
Air Temperature ◽  
Daily Rainfall ◽  
Climatic Conditions ◽  
Dry Season ◽  
Climate Impacts ◽  
Calling Behavior ◽  
Wet Season ◽  
Focal Species ◽  
Calling Activity ◽  
Vocal Activity

Climatic conditions represent one of the main constraints that influence avian calling behavior. Here, we monitored the daily calling activity of the Undulated Tinamou (Crypturellus undulatus) and the Chaco Chachalaca (Ortalis canicollis) during the dry and wet seasons in the Brazilian Pantanal. We aimed to assess the effects of climate predictors on the vocal activity of these focal species and evaluate whether these effects may vary among seasons. Air temperature was positively associated with the daily calling activity of both species during the dry season. However, the vocal activity of both species was unrelated to air temperature during the wet season, when higher temperatures occur. Daily rainfall was positively related to the daily calling activity of both species during the dry season, when rainfall events are scarce and seem to act as a trigger for breeding phenology of the focal species. Nonetheless, air temperature was negatively associated with the daily calling activity of the Undulated Tinamou during the wet season, when rainfall was abundant. This study improves our understanding of the vocal behavior of tropical birds and their relationships with climate, but further research is needed to elucidate the mechanisms behind the associations found in our study.

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