Sap Yield Research Articles

Tapping below the lateral line does not reduce maple sap yield or quality

Modern maple sugaring operations use vacuum tubing systems to enhance sap flow and maximize yield. The positioning of tapholes is a crucial aspect influencing tree health and sap yields, but is limited by dropline length. Inverting droplines to expand the tappable zone and reduce the risk of over-tapping has raised concerns about vacuum efficiency and microbial contamination.We examined over 2200 trees on multiple high-vacuum 5/16″ tubing systems at two sites over three seasons, tapping at various heights above and below the lateral line. Our analysis showed no significant decrease in sap yield or sugar concentration when tapping below the lateral line. Taps at extreme heights above the lateral line produced slightly more sap (estimated at 0.6 l of sap per tap for a good production season) and marginally sweeter sap (0.06 °Brix). However, differences in vacuum management had a more significant impact on yield. Additionally, there was no evidence of increased microbial activity or changes in sap pH due to relative tapping height.These findings demonstrate that tapping below the lateral line effectively doubles the tappable zone without significantly affecting sap yield or quality, promoting sustainable maple sugaring practices by ensuring long-term productivity without compromising sap yields or quality.

Study on the changes during the fermentation of the wine prepared from palm (Phoenix sylvestris) sap

The sugary sap of different palm trees is fermented to create palm wine, an alcoholic beverage. This work was aimed at studying the changes that occur during the fermentation process of wine made from the sap of the wild date palm species Phoenix sylvestris. At first, the best age of the palm tree was determined by observing total soluble solid and sap yield for 24 h and was found to be middle-aged palm plants (15–40 years old). Pure wine yeast (Saccharomyces cerevisiae SC22) and a natural starter culture were added to the palm saps, adjusting the total soluble solid (TSS) to 21.5° brix (°Bx). Total titratable acidity, pH, volatile acidity, reducing sugar, non-reducing sugar, total sugar, alcohol content, ester content, and aldehyde contents were the parameters under investigation. The statistical analysis showed significant (p ≤ 0.05) changes in the physico-chemical and volatile constituents of palm sap during the fermentation process in both systems. Sensory evaluation revealed that palm wine fermented with pure yeast culture was significantly superior to natural, spontaneously fermented wine. The acceptability test showed that the ideal characteristics of palm wine are cloudy in appearance, fruity in aroma, and sweet in taste.

Sap Yield and Sugar Content of Boxelder and Norway Maple Trees in Northern Utah

Maple syrup is a well-known natural sweetener made from the sap harvested from maple trees (Acer sp.). The North American scientific literature regarding maple syrup has predominantly originated in the Northeastern United States and Canada. However, the range of this Holarctic genus extends across the continent and all species produce sap with the potential for syrup production. This study focuses on two maple species commonly found in Northern Utah, namely the native boxelder (Acer negundo) and the introduced Norway maple (Acer platanoides). Thirty trees of each species were tapped in Cache Valley, UT, USA, on 19 Feb 2022, and measured for daily sap yield and sugar content until the season ended 37 days later on 27 Mar 2022. The same trees were re-tapped on 1 Mar 2023 and taps were removed 41 days later on 10 Apr 2023. Average 2022 sap yields were 22.1 L for boxelder and 7.5 L for Norway maple per tree. In 2023, average sap yields were 26.4 L for boxelder and 9.3 L for Norway maple per tree. Boxelder trees produced an average sap yield more than double that of Norway maple in both years. Sugar content was similar for both species ranging from 2.2% to 2.8%. Air temperatures were analyzed using data from Utah AgWeather System weather stations nearest to the trees, and air temperature had a significant impact on sap yield. It was found that an average daily air temperature of 0.5 °C and a daily air temperature difference of ∼10 °C with a minimum air temperature close to −5 °C and a maximum air temperature of ∼6 °C was the optimal condition for production. An analysis of the mineral nutrient concentrations in the sap and soil showed no correlation. These findings indicate that there is potential for using Utah’s maple species for syrup production.

Analysis of the potential and characteristics of Nipa(Nypa fruticans)as a sustainable biofuel alternative source in Indonesia

A sustainable energy source, one that doesn’t compete with food production, is crucial for enhancing national energy independence. This study assesses the feasibility of Nipa palm (Nypa fruticans) as a biofuel source in Indonesia. The research involved vegetation and laboratory analyses to determine Nipa palm’s potential for biofuel production. The results revealed a Nipa density of 3,167 trees ha-1with a mesocarp yield of 3.99 tons ha-1and sap yield of 177.35 kL ha-1. The mesocarp contains 39.37% carbohydrates, and the sap has a total sugar content of 13.13%. National estimates for mesocarp and sap production were 3,339,630 tons year-1and 148,443 thousand kL year-1, respectively. Estimated bioethanol production from Nipa sap was 13,330 thousand kL year-1. Incorporating Nipa bioethanol into the national fuel supply would increase it to 66,766 thousand kL year-1(24.95%), while reducing imports to 14,531 thousand kL year-1(47.86%). In conclusion, Nipa palm offers significant advantages as a potential biofuel feedstock, particularly for bioethanol production, without compromising food supplies.

Sugar maple sap, soil, and foliar chemistry in response to non-industrial wood ash fertilizer in Muskoka, Ontario

Non-industrial wood ash may be an effective forest soil nutrient supplement but its use in Canada is largely restricted because of unknown concentrations of trace metal contaminants. Sugar maple ( Acer saccharum Marshall) is particularly sensitive to low soil calcium (Ca) levels, and though maple syrup is of great economic importance in Canada, it is unknown how wood ash could affect sap chemistry. Non-industrial wood ash (NIWA; 6 Mg·ha−1) applied to experimental plots in Muskoka, Ontario was rich in Ca (27%), while metal concentrations were well below provincial regulatory limits. One-year post-application, significant increases were observed in the treated plots in the soil pH and base cations (Ca, K, and Mg) in the surface soil horizons, and metal concentrations in the litter. Sap yield in the control plots was significantly lower in the first-year post-application than in the second year, but no other differences were found. In both tapping years, sap sweetness remained similar and differences in nutrient and metal concentrations between treatments were generally small and inconsistent. Foliar chemistry remained largely unchanged 1 year following application, except for K that was twice as high in the treated plots. Ultimately, NIWA is unlikely to significantly alter sugar maple sap chemistry, indicating that it is a viable nutrient supplement that can enhance soil fertility in sugar bushes with no impact on sap sweetness.

Nutrition and Related Factors Affecting Maple Tree Health and Sap Yield

The maple industry is an economically important bioresource for both Canada and the Northeastern United States, with Canada being the world leader in maple products. Maple sap is collected during the natural freeze-thaw cycles which occur in the late winter and early spring. Syrup yield is directly dependent on sap yield which has links to tree health, available nutrients, forest health, environment, soil health, sap components, season length, as well as various other factors. Maple trees can tolerate a wide arrange of soils, but soils in the maple woods are often left alone due to the difficulty with addition and incorporation of the appropriate amendments. Most nutrients come from the nutrient cycling of decomposing litter and mycorrhizal associations. Nutrient deficiencies of K, P and Ca are all linked to maple decline and could be positively influenced by a fertilization program. However, improper nutrient applications could create even greater nutrient imbalances, thus leading to more dieback or decline. This review discusses current maple management practices with an emphasis on the role of soil nutrition on tree health and sap yield.

A model for the sap yield of birches tapped by citizen scientists

The sap yield of birches ( Roth and Ehrh.) was modelled as a function of tree diameter (girth) at breast height, as well as site and stand characteristics measured and reported by citizen scientists representing mainly non-industrial private forest owners in the South Savo, North Karelia, and Northern Ostrobothnia regions in Finland. Birches (tree species not recorded) growing on both mineral and peatland sites were tapped during the springs of 2019 and 2020. Citizen scientists were mainly voluntary forest owners who received the instructions and equipment (spouts, drop lines and buckets) for collecting sap from three birches of different diameters in the same birch stand. Citizen scientists were instructed to measure and report the sap yield and girth of the trees, as well as stand characteristics from the forest resource data, if available. Based on the linear mixed model fitted to the data, the sap yield increased with the increasing tree diameter and mean stand height, and varied between years, stands, and trees; between-region variation was not significant. In a birch stand, the simulated total sap yield ha–1 was depended on the average tree size and the stem number ha–1 and was at its highest just before the first commercial thinning and again before the second thinning. The sap model can be used to predict the necessary sap yield in profitability analyses for sap tapping.Betula pendulaB. pubescens

Preliminary Investigation of The Potential of Coconut Sugar Production Using Dwarf Varieties

Coconut sugar is one of the high economic value products. The production of coconut sugar In Indonesia is about 300,000 tonnes/year. During the last few years, the supply of raw materials for the coconut sugar product has diminished due to stagnant production caused by the lack of coconut climbers collecting coconut sap. The scarcity of labor is caused by several factors, especially young tappers who are less interested in climbing tall coconut palms. To solve this problem, it is necessary to evaluate the potency of dwarf coconuts, with short trunk and fast fruiting. The objective of this study was the evaluation and selection of Dwarf coconut varieties that have high yield potential as a producer of sap and coconut sugar. The research was conducted in North Sulawesi Province by evaluating 9 Dwarf coconut varieties. The results of research on the production of coconut sap and sugar from 9 Dwarf coconut varieties with different plant ages, gave mixed results among coconut varieties. The length of tapping sap varied between 31.42 - 43.21 days/bunch, the volume of sap varied between 1.1 - 3.3 liters/tree/day, the pH of sap ranged between 6.49 - 7.86 and the Brix value varied between 14.01 - 17.64. The most important traits such as the sap yield and sugar production also varied from 14.54 to 18.95% among varieties, and between 0.16 to 0.42 kg/tree/day respectively. The Dwarf coconut varieties with the highest potential yield of sap and sugar are the Waingapu Red Dwarf (WRD), Salak Green Dwarf (SGD), and Nias Yellow Dwarf (NYD), with the potential sugar yield of 2.09 tons, 1.64 tons, and 1.56 tons/month/ha respectively. It is hoped that these Dwarf coconut varieties would be attractive for young tapers and could be introduced to farmers in several Provinces for tapping purposes for the production of coconut sugar.

Determination of Some Agricultural and Technological Characteristics of Second Product Sweet Sorghum [Sorghum bicolor (L.) Moench] in Şanlıurfa Conditions

Bu çalışma, 2016-2017 yıllarında ikinci ürün olarak GAP Tarımsal Araştırma Enstitüsü Müdürlüğüne bağlı Talat Demirören araştırma istasyonunda altı tatlı sorgum (Dale, M81-E, PHS 12-10, Urja, Top 76-6, Theis) çeşidinin bazı tarımsal ve teknolojik özelliklerinin belirlenmesi amacıyla yürütülmüştür. Deneme tesadüf blokları deneme desenine göre dört tekerrürlü olarak kurulmuş, parseller sıra arası 70 cm, sıra üzeri 20 cm olacak şekilde beş sıralı olarak düzenlenmiştir. Araştırma sonuçlarına göre; çeşitlerin ana sap çapları 22.53-28.83 mm, yeşil ot verimi dekara 10 633-16 172 kg arasında, yapraksız sap verimi dekara 9 117-13 413 kg arasında değişmiştir. Teknolojik özelliklerden, kuru madde oranı %19.1-26.1, özsu verimi, şeker verimi ve biyoetanol verimi sırasıyla 3 658-5 163 l da-1, 394-928 kg da-1 ve 160-237 l da-1 arasında değişmiştir. Araştırma sonuçlarına göre, tatlı sorgum çeşitlerinin farklı kullanılması amaçlandığında; yeşil ot verimi, özsu verimi, şeker verimi yönünden Urja, biyoetanol verimi bakımından ise M81 E çeşidi tavsiye edilen çeşitler olmuşlardır.

A Changing Climate in the Maple Syrup Industry: Variation in Canadian and U.S.A. Producers’ Climate Risk Perceptions and Willingness to Adapt Across Scales of Production

Maple syrup production (“maple sugaring”) is an important cultural and economic activity in eastern Canada and the northeastern United States (U.S.A.). Climate change is a concern for maple producers because maple sugaring is dependent upon climate for both sap sugar content as well as for the specific patterns of freezing and thawing in springtime needed for sap flow. Meanwhile, the maple industry itself is in transition: historically, maple sugaring has been a small-scale seasonal activity, but today large producers tap thousands of trees, contributing to a widening gap in production volumes and production practices between small- and large-scale producers. Drawing on original survey data from 354 maple producers in Canada and the United States we ask how attitudes towards climate change risks and adaptation strategies differ between smaller-scale and larger-scale producers. Findings suggest that small-scale, medium-scale and large-scale maple producers have different perceptions of climate change risks, report different impacts of climate change on maple sap yields, and have different levels of willingness to use adaptation strategies ranging from tapping more trees to adopting new production technologies. In multivariate ordered logistic regression models controlling for producer age, education, and political affiliation, we consistently find the strongest correlates of attitudes towards climate change risks—and the willingness or ability of producers to adopt different adaptation strategies—are country of residence (with preferred adaptation strategies varying across Canada versus the U.S.A.) and producer scale (with larger producers adopting more adaptation strategies). We conclude that more detailed and up-to-date information on the different types of maple operations—including effects of climate change on maple sugaring and available adaptation strategies across geographies and across scales of production—is needed to help maple producers, maple producer associations, and policymakers understand how the maple industry is evolving and how best to prepare for the future.

Management, morphological and genetic diversity of domesticated agaves in Michoac\xe1n, M\xe9xico

BackgroundPulque is a fermented beverage prepared with sap of Agave species in Mexico. Management of agaves for this purpose has motivated domestication of some species and high phenotypic variation that commonly causes uncertainty about the taxonomic identity of varieties traditionally managed by people. This study assumed that varieties of crop species continually arise from mutations, sexual reproduction and hybridization, among other processes, and some of them are favoured and maintained by humans. Identifying these varieties may be difficult and a challenging issue for botanists and evolutionary biologists studying processes of domestication. Through a case study, we analysed the traditional varieties of agaves used to produce pulque in Michoacán, Mexico. We aimed at identifying the varieties, analysing the relatedness among them and developing a methodological approach that could help solve taxonomic problems and study variation under domestication of this and other plant groups. We documented (1) the traditional varieties of agave used and their identity, (2) how these varieties are perceived, used and managed by the local people and (3) how management influences phenotypic and genetic variation among varieties.MethodsWe interviewed pulque producers in two localities of the state of Michoacán, Mexico, where we recorded management practices of agaves, the traditional varieties used, the attributes characterizing those varieties, the varieties preferred by people, and features and mechanisms of selection. We conducted multivariate analyses of morphological features of the agave varieties, as well as genetic diversity and genetic distance studies among agave varieties through 11 nuclear microsatellites.ResultsSeven traditional varieties of Agave were recorded in the study area. Multivariate analyses of morphology identified varieties belonging to the species A. salmiana, A. mapisaga and, presumably, A. americana. The preferred varieties have morphological features selected to make easier their management and produce higher sap yields. Genetic diversities (HE = 0. 470 to 0.594) were high compared with other Agave species with similar life history traits and use. Genetic distance analyses grouped the varieties “Verde” and “Negro” (identified as A. salmiana), whereas the varieties “Tarímbaro” and “Listoncillo” (identified as A. mapisaga) formed another group. The varieties “Blanco” and “Carrizaleño” (most probably being A. americana) clustered with varieties of A. salmiana, whereas the variety “Cenizo” appeared as a distinct group. Bayesian analysis indicated that most individuals of varieties of A. salmiana form a group and those of the varieties of A. mapisaga form another, whereas individuals of the varieties putatively belonging to A. americana clustered in similar proportions with both groups.ConclusionsThe traditional pulque production in the study area is an ongoing practice. It is still an important source of products for direct consumption by households and generation of economic incomes and as part of the cultural identity of local people. The most used traditional variety exhibited a marked gigantism, and although these agaves are mainly asexually propagated, populations have high genetic diversity. The local producers promote the maintenance of different traditional varieties. Our study shows the value of an integral research approach including ethnobiological, morphological and genetic information to clarify the state of variation influenced by humans on agaves, but it would be helpful to study other organisms under domestication. In addition, such approach would help to document human and non-human mechanisms generating crop varieties managed by local people.

Utilization of Sap from Part of Kepok Banana Tree (Musa Mcuninata Balbisianacolla) with Variation of Extraction Solutions as Textile Dyes

The purpose of this study was to obtain tannin natural dyes from the sap of the fronds / stalks of kepok banana leaves, namely the percentage of yield, color intensity, time and good solvents for taking the most dyes in the sap of the banana tree. The extraction of dyes in various parts of banana trees was carried out by means of an extraction process using soxchlet, with a medium of distilled water, methanol, ethanol and ethylacetate. The raw material was sliced, dried to + 6.7% moisture content, ground powder made from size 60-80 mesh. The powder was weighed 50 grams and extracted with each medium solution in 500ml at each evaporation temperature, the results were evaporated to dryness. Test the tannin color intensity with a spectrophotometer. The results showed that the optimal amount of sap yield on the banana midrib was 16,248%, the color intensity of tannin obtained was 0.218 in methanol solvent products. The solvent which can provide the optimal yield in extracting tannins from banana leaf midrib was methanol. The time of the extraction process to the maximum out tannin was 4-4.5 hours

Effect of the new high vacuum technology on the chemical composition of maple sap and syrup

BackgroundTechniques used to produce maple syrup have considerably evolved over the last decades making them more efficient and economically profitable. However, these advances must respect composition and quality standards as well as authenticity of maple products. Recently, a new and improved high vacuum technology has been made available to producers to achieve higher sap yields. The aim of the present study was therefore to evaluate the effect of this new system on the yield of sap and on the sap and syrup chemical composition. ResultsSap yield was monitored during the 2013 and 2014 seasons for high vacuum collection systems (25–28 InHg) and compared to the control systems (20 InHg). Samples of sap and syrup were also collected for chemical analysis. During the 2013 season, a sap volume of 166.19 L/tap was recorded at 25 InHg vacuum level while the control vacuum level permitted to collect 139.47 L/tap, corresponding to a yield increase of 19.2 %. The following season, a yield increase of 38.2 % was measured when control and 28 InHg vacuum levels were compared with 118.06 and 163.13 L/tap, respectively. Results on the pH, color, flavor, minerals, sugars, organic acids, total polyphenols, total nitrogen, abscisic acid and auxin (Indol-3-acetic acid) showed no major differences between high vacuum technology and the control with values remaining within ranges previously published. ConclusionResults showed that a use of high vacuum systems increased sap yield and had no major impact on the quality and purity of maple sap and syrups compared with the control systems.

Characterization of reproductive morphological characteristics of sugar palm (Arenga pinnata) and its relationship with sap yield and Brix value

Arenga pinnata (sugar palm) is a multipurpose palm species with interesting economic potential, well known for the high sugar content of its sap. We characterized various morphological characteristics of male and female inflorescences and correlations between these parameters and sap yield were determined. We found strong correlations between peduncle girth and various morphological parameters in both types of inflorescence. Our results revealed a highly significant correlation between the average sap volume/day and various morphological parameters of male inflorescences such as the peduncle girth and average rachillae length. These morphological parameters are proposed as potential indicators for the identification of superior germplasm with high sap yield.

Effects of bamboo charcoal-based bio-fertilizer on wine bamboo sap yield and nutrient composition

To explore fertilization methods for wine bamboo cultivation in southwestern semi-arid areas of China, this study analyzed annual changes in sap yield and nutrient composition from May 2013 to March 2015 by using bamboo charcoal-based bio-fertilizer (ZT) and organic fertilizer treatments (CK). The study also provided basic data for functional beverage preparation and for application of ZT. The results of the two experimental cycles revealed that under the ZT treatment, sap was available for collection from May, the beginning of the rainy season, to November, the beginning of the dry season. The period of abundance was July to October with the highest yield of sap of 3.18 L stalk−1 in September, 2014, still lower than the moso bamboo sap, which was likely due to the scale of sap production of monopodial bamboos being different from that of sympodial bamboos. In January, trace amounts of sap were still detected, suggesting that the effect of the treatment was significant. Moreover, in the dry season, soil water content and soil temperatures at 10–15 cm depths indicated that the fertilizer had the ability to maintain soil temperatures and moisture. In both fertilizer treatments, the correlation between the collected sap and environmental parameters was significant. In the ZT treatment for the entire 2 years, the effectual environmental factors were soil water at 10–15 cm, air temperatures, and wind speeds. The same determining factors were observed for the rainy season. In the CK treatments, the effectual environmental factors for the entire year and the rainy season were soil water at 0–5 cm and air moisture. The bamboo charcoal-based bio-fertilizer elevated the potassium, calcium, iron, manganese, copper, and total phosphorus content, simultaneously increasing the sap yield, protein and reducing sugar contents, and with a relative increase in sap pH. The wine bamboo sap contained 18 amino acids. Glutamic acid, alanine and proline were the most abundant. Compared to the controls, the treatment showed higher levels of all amino acids. Thus, the ZT treatment could be more beneficial to the development of root systems because the function of heat preservation and moisture retention prolong the sap collection period, increase sap yields, and elevate mineral element, conventional nutrients, and amino acid contents with evident fertilization effects and broader application prospects.

ALOE SECUNDIFLORA SAP YIELD AND QUALITY VARIATION IN KWALE, KENYA

Aloe secundiflora contributes to over 90% of traded aloe gum in Kenya. It is also the most common aloe species grown in Kwale County for commercial exploitation. The sap quantity and quality variation of Aloe secundliflora in the County was studied to provide information for investment decisions. Samples were obtained from 41 sites from 10 locations in Kinango and Msambweni sub-counties. All the aloe plants within a circular sample plot (0.01 ha) at the centre of each farm were counted and recorded. The total area of each farm was established using a GPS. The mean sap yield was obtained from 3 leaves (large, medium and small) from at least 10 aloe plants per plot. The moisture and ash contents of the sap were established at KEFRI Karura laboratories using standard procedures. The results indicate a significant (P<0.05) variation in the number of harvestable leaves per aloe plant (mean 13; Range 5 to 31), with sites. The mean sap yield per aloe plant was 68.3 ml (Range 8.3 to 380 ml) but no significant variation with sites. It is estimated that the potential aloe gum yield is 175.3 Kg per hectare (worth about KShs. 45,578), the mean moisture content is 36.6 % (ranging from 27. 8 to 41 %) while the mean ash content is 2.7 % (ranging from 1.3 to 3.4%). It is observed that the Aloe secundiflora grown in Kwale has an acceptable ash and moisture content but a low sap yield. It is concluded that Aloe secundiflora in Kwale has acceptable ash content but a low sap yield. It is recommended that higher yielding varieties of indigenous aloes be produced and promoted for commercial exploitation. Financial analysis of aloe growing should also be carried out to establish the profitability of the enterprise.

ALOE SECUNDIFLORA SAP YIELD AND QUALITY VARIATION IN KWALE, KENYA

Aloe secundiflora contributes to over 90% of traded aloe gum in Kenya. It is also the most common aloe species grown in Kwale County for commercial exploitation. The sap quantity and quality variation of Aloe secundliflora in the County was studied to provide information for investment decisions. Samples were obtained from 41 sites from 10 locations in Kinango and Msambweni sub-counties. All the aloe plants within a circular sample plot (0.01 ha) at the centre of each farm were counted and recorded. The total area of each farm was established using a GPS. The mean sap yield was obtained from 3 leaves (large, medium and small) from at least 10 aloe plants per plot. The moisture and ash contents of the sap were established at KEFRI Karura laboratories using standard procedures. The results indicate a significant (P<0.05) variation in the number of harvestable leaves per aloe plant (mean 13; Range 5 to 31), with sites. The mean sap yield per aloe plant was 68.3 ml (Range 8.3 to 380 ml) but no significant variation with sites. It is estimated that the potential aloe gum yield is 175.3 Kg per hectare (worth about KShs. 45,578), the mean moisture content is 36.6 % (ranging from 27. 8 to 41 %) while the mean ash content is 2.7 % (ranging from 1.3 to 3.4%). It is observed that the Aloe secundiflora grown in Kwale has an acceptable ash and moisture content but a low sap yield. It is concluded that Aloe secundiflora in Kwale has acceptable ash content but a low sap yield. It is recommended that higher yielding varieties of indigenous aloes be produced and promoted for commercial exploitation. Financial analysis of aloe growing should also be carried out to establish the profitability of the enterprise.

Nipa (Nypa fruticans Wurmb) Sap Collection in Southern Thailand I. Sap Production and Farm Management

Nipa (Nypa fruticans Wurmb) sap/sugar production has been practiced sustainably over a hundred years in southern Thailand. Farming techniques such as tapping were established over the times, however the variation of sap/sugar production and its regulating factors are not yet fully recognized. The daily sap yield and the sugar content were monitored for three years (2010, 2011 and 2012) in 7 nipa farms. The daily sap yield varied from 0.02 to 2 litres per fruit stalk with the sugar content ranging from 10.6 to 28.6%. The duration of sap production from the same fruit stalk was from 20 days to 56 days and the mean sugar content of 1,892 measurements was 18.1%. Although the density of the fruit stalks was of minimal significance, the growths of the fruit stalk were significantly related to sap production. Thicker and longer fruit stalk produced more sap. Water inundation affected the growths of the fruit stalk resulting in a decrease in sugar production 4 to 5 months after the rainy season. Nipa farms in the study site produced sugar at the rates of 3.2 to 6.5 tons/ha/year nevertheless farm management to increase growths of fruit stalk and to reduce impact of water inundation could enhance nipa sap/sugar production.

SAP YIELD VARIATION OF Caryota urenus

Caryota urenus is know as palm (Wine palm). It belongs to the family Palmaceae and plays an important role in the village economy of Sri Lanka. The most important non-wood forest product of palm is the sap. The sap yields were estimated for more than 200 tappers in Matara district. This was organized with school teachers and students. The yield varied from 472.5 ml to 16,500 ml per day per palm. Two common types were recognised. They are the tall type having straight and cylindrical trunks and identified as Perimi kitul and the Barrall type having a greater diameter in the upper trunk than at ground level and called Gahanu kitul. The barrall type of recorded higher yields than the tall type. The shape of the inflorescence can be categorized into two major types, elongate and compact. The compact type produced more sap yield than the elongate type. The sap yield variation during the period of day and night was further examined. Night yield was measured in the early morning and the Day yield late evening. Significant yield differences were observed during day and night collecting. More yield was recorded for the night collection.

Modelling the effect of climate on maple syrup production in Québec, Canada

Due to the exceptional sweetness of its sap, sugar maple ( Acer saccharum Marsh.) is economically exploited at a commercial scale for maple syrup production in northeastern North America. Approximately 80% of world production is realised in the province of Quebec, Canada, where it is economically important for rural communities. Despite important financial investments in industrial infrastructure over recent decades, the maple syrup yield (ml of sap/tap/year) has followed a general declining trend over the last 15 years, presumably because of unfavourable climatic conditions. In this study, the relationship between climate and maple syrup yield by tap for the whole province was investigated. A multiple regression model using four monthly climatic variables (mean January and April temperature and maximum temperature in February and March) explained 84% of the annual variation in yield between 1985 and 2006. This model was used to predict sugar maple syrup yield using a data set of future climatic scenarios issued from a large number of global climate models driven by different scenarios of CO 2 emissions. The results show that sap yield of sugar maple should decrease by 15 and 22% in 2050 and 2090, respectively, as compared to the 1985–2006 period. The increase in mean April temperature was responsible for most of the reduction in yield. Assuming that the variables included in the prediction model are expressing a pattern of successive climatic conditions that could be displaced in time, i.e., that may happen sooner in the season, the maple syrup yield could be maintained at its current level if the period of sap production can shift in time to occur 12 days and 19 days sooner in 2050 and 2090, respectively. Other potential effects of climate change on sugar maple range and health that could also affect the yield of maple syrup production in the future were not addressed in this study.