A Critical Overview of Forestry Seedling Production Policies and Practices in Relation to Smallholder Forestry in Developing Countries

This paper reviews forestry seedling production systems in South-east and East Asia and identifies problems with respect to seedling quality, seedling distribution and financial sustainability, and measures which have been adopted or advocated to improve performance in this sector. The paper draws in particular on experience in a series of research projects on smallholder forestry in the Philippines. Some observations are also drawn from the following papers in this combined special issue of Small-scale Forestry. It is found that a mix of public and private sector models are adopted for forestry seedling production, between and even within countries. Often nurseries are set up to provide seedlings for a government-directed expansion in tree planting, and have difficulty surviving once the initial planting purpose is completed. Private nurseries often lack resources, and depend on contracts to supply seedlings for financial viability. Demand tends to be highest for fast-growing species (often exotics), fruit trees, and ornamentals in the case of urban nurseries. Government policies typically favour quantity over quality of the seedlings produced. Considerable scope exists for adopting best or at least improved management practice in seedling nurseries.     

Enhancing Tree Seedling Supply to Smallholders in Leyte Province, Philippines: An Evaluation of the Production System of Government Nursery Sector and Support to Smallholder Tree Farmers

A decentralized seedling production is regarded as the most effective means of providing smallholders with planting materials. However, the sustainability of smallholder nursery operation is constrained by several factors, including the limited availability of germplasm, lack of technical skills and low seedling demand low viability of seedling market. The government nursery sector could complement the weaknesses of the smallholder nursery group but government nurseries are not operating effectively to enhance the availability of high quality seedlings of a wide species base for smallholder forestry. Seedling production in government nurseries is quantity-orientated with low emphasis on the production of high quality planting materials. Germplasm used in seedling production is mostly collected from unselected sources and seedlings produced are mostly of low physical quality. The species selection in government nurseries is heavily based on the availability of germplasm which resulted in the production of a few species which are commonly raised on private nurseries. The duplication of species of most seedlings raised in government nurseries with those produced in private nurseries and the far distance of government nurseries from the villages has resulted in low uptake of seedlings by smallholder tree farmers. For the government nursery sector to become more effective in providing support in the present paradigm of decentralized seeding production, a change from its production system and a broadening of the role it plays is needed. The social mobilization on seedling production as a scheme of implementing the Green Philippines Program has led the Department of Environment and Natural Resources to acknowledge the seedling production activity of private individual and communal nursery groups. This can be an opportunity for organizing the private and government nursery sectors to promote the operational effectiveness of the overall forest nursery industry.     

Length of the plateau and pipping stages of incubation affects the physiology and survival of turkeys.

1. The hypothesis tested was that accelerating the rate at which a turkey embryo passes through the Plateau and Pipping stages (incubation days 25 to 28) affects growth and embryonic mortality. 2. Eggs from 4 genetic lines were incubated similarly until 24 d of incubation. The eggs were divided at random, half incubated at 36.8 degrees C (CON) and the remaining half incubated at 37.3 degrees C (FAST). 3. The passage time for each developmental stage was recorded at 4 h intervals. Tissues were collected and measured for growth, and glycogen concentration at each developmental stage in response to the accelerated development. 4. The FAST treatment accelerated passage through the Plateau in some lines but not others, but time to pip was shortened in all genetic lines. Embryonic survival rate was affected differently by FAST. Slower growth in response to FAST enhanced survival. 5. In conclusion the rate at which genetically different embryos grow, mature and survive may involve choices among the 3 processes.     

Seasonal and nutritional effects on the fatty acids of three species of shrimp, Penaeus setiferus,P. aztecus and P. duorarum

The fatty acids of three species of shrimp from the Gulf of Mexico, white (Penaeus setiferus), brown (P. aztecus), and pink (P. duorarum), were analyzed periodically for 1 year. The fatty acid patterns of varied species of shrimp collected at the same time of the year differed very little from each other. On the other hand, a slight but distinctive seasonal variation of the fatty acid composition, irrespective of Penaeus species, was observed. Saturated fatty acids increased during the warm seasons and decreased during the cold months, while the opposite behavior was exhibited by monoenoic and polyenoic fatty acids. When the variations in fatty acid levels were compared to the temperature of the water, there was a 2-month lag period between a change in water temperature and the corresponding variation in fatty acid composition. This slow alteration of the shrimp fatty acids suggests that the changes are effected through the food chain rather than by endogenous adjustment to an alteration in water temperature.Further studies were performed in which the fatty acid patterns of pond- and laboratory-reared shrimp were compared with those of their food. Evidence was obtained confirming the significant effect of diet on the fatty acids of shrimp lipids. Shrimp incorporated certain dietary fatty acids readily but showed little ability for the conversion of C₁₈ polyunsaturated fatty acids into C₂₀ and C₂₂ fatty acids of higher unsaturation. Thus, the C₂₀ and C₂₂ fatty acids which are essential for shrimp growth cannot be substituted in the diet by C₁₈ precursors.Considered in toto, these experiments suggest that diet exerts a strong influence on the composition of shrimp body lipids and that, contrarily, endogenous synthesis or modification occurs to a low degree.     

Oxidative response of neutrophils to platelet-activating factor is altered during acute ruminal acidosis induced by oligofructose in heifers

Reactive oxygen species (ROS) production is one of the main mechanisms used to kill microbes during innate immune response. D-lactic acid, which is augmented during acute ruminal acidosis, reduces platelet activating factor (PAF)-induced ROS production and L-selectin shedding in bovine neutrophils in vitro. This study was conducted to investigate whether acute ruminal acidosis induced by acute oligofructose overload in heifers interferes with ROS production and L-selectin shedding in blood neutrophils. Blood neutrophils and plasma were obtained by jugular venipuncture, while ruminal samples were collected using rumenocentesis. Lactic acid from plasma and ruminal samples was measured by HPLC. PAF-induced ROS production and L-selectin shedding were measured in vitro in bovine neutrophils by a luminol chemiluminescence assay and flow cytometry, respectively. A significant increase in ruminal and plasma lactic acid was recorded in these animals. Specifically, a decrease in PAF-induced ROS production was observed 8 h after oligofructose overload, and this was sustained until 48 h post oligofructose overload. A reduction in PAF-induced L-selectin shedding was observed at 16 h and 32 h post oligofructose overload. Overall, the results indicated that neutrophil PAF responses were altered in heifers with ruminal acidosis, suggesting a potential dysfunction of the innate immune response.     

Influence of mass and volume of ruminal contents on voluntary intake and digesta passage of a forage diet in steers.

To assess the influence of volume and mass of ruminal contents on voluntary intake and related variables, five ruminally cannulated steers (550 kg) were fed a low-quality forage diet (43.1% ADF, 8.1% CP) in a 5 x 5 Latin square experiment. Mass and volume of ruminal contents were altered by adding varying numbers and weights of filled tennis balls (6.7-cm diameter) to the rumen immediately before the initiation of each experimental period. Treatments consisted of 0 balls (control), 50 balls with a 1.1 specific gravity (SG), 100 balls with a 1.1 SG, 50 balls with a 1.3 SG, and 100 balls with a SG of 1.3. The total volume of balls was 7.25 and 14.5 L for 50 and 100 balls, respectively. The total weight of balls was 8.5 and 17 kg for 50 and 100 balls with a 1.1 SG and 10.75 and 21.5 kg for 50 and 100 balls with a 1.3 SG, respectively. Daily DMI was 8.3, 7.3, 7.0, 6.5, and 6.0 kg for control; 50, 1.1 SG; 50, 1.3 SG; 100, 1.1 SG; and 100, 1.3 SG, respectively. Addition of balls to the rumen reduced (P < .01) DMI. Increasing the number (P < .01) and SG (P <. 01) of the balls decreased DMI further. However, digestibilities of DM, NDF, ADF, and CP were not influenced by treatment. Increasing the number of balls in the rumen increased (P < .05) rate of passage of digesta from the rumen, but increasing SG of the balls did not alter rate of passage. There was a treatment x hour interaction (P < .05) in the proportion of ruminal digesta with a functional specific gravity (FSG) less than 1.1, which decreased with time after feeding for the control but increased with time after feeding for other treatments. Ruminal passage rate of inert particles added in the rumen of different SG (1.1 and 1.3) and length (1 and 3 mm) decreased (P < .05) as SG of the balls increased. Mean fecal particle size was greater for those treatments with the heavier balls. Both the number and SG of balls (P < .10) influenced total VFA, and total concentrations were greater for the control and for the 1.1 SG than for the 1.3 SG treatments.     

Possible genetic variation in resistance of turkeys to erysipelas and fowl cholera

Natural disease outbreaks of erysipelas and fowl cholera occurred in several lines of turkeys maintained for genetic studies. There were line differences in mortality during both outbreaks, suggesting that there is genetic variation in resistance to these diseases. A line developed by selection for increased egg production had a higher mortality rate from fowl cholera than did the randombred control line from which it was developed. Both the egg line and its control line had a lower mortality rate in the erysipelas outbreak than did a line selected for increased growth rate. Both diseases induced high mortality in a line selected for increased growth.     

Will nutrient-efficient genotypes mine the soil? Effects of genetic differences in root architecture in common bean (Phaseolus vulgaris L.) on soil phosphorus depletion in a low-input agro-ecosystem in Central America

Crop genotypes with root traits permitting increased nutrient acquisition would increase yields in low fertility soils but have uncertain effects on soil fertility in the long term because of competing effects on nutrient removal vs. the soil conserving effects of greater crop biomass. This study evaluated the relative importance of phosphorus loss in crop extraction vs. phosphorus loss in soil erosion as influenced by genetic differences in root shallowness and therefore phosphorus uptake in common bean (Phaseolus vulgaris L.). Six recombinant inbred lines of varying root architecture and two commercial genotypes of bean were grown in unfertilized, steeply sloped (32%), low phosphorus (5.8 mg kg^?1, Fe-strip) Udults in Costa Rica. Fertilized (60 kg total phosphorus ha^?1) plots of commercial genotypes were also included in the study. Runoff was monitored throughout the bean growing season in 2005 and 2006, and in 2006, monitoring continued through the maize growing season. Phosphorus removed in plant biomass at harvest through the 2006 bean–maize crop cycle averaged 7.3 kg ha^?1 year^?1, greatly exceeding phosphorus loss due to erosion (0.15–0.53 kg ha^?1 year^?1) in unfertilized plots. In fertilized bean plots, total biomass phosphorus averaged 6.32 kg ha^?1 year^?1 and total eroded phosphorus averaged 0.038 kg ha^?1 year^?1, indicating rapid sorption of fertilizer phosphorus. Shoot growth of several recombinant inbred lines under low phosphorus was comparable to that of fertilized commercial genotypes, illustrating the effectiveness of selection for root traits for improving plant growth in low-phosphorus soils. Genotypic differences in root architecture of recombinant inbred lines led to 20–50% variation in groundcover by shoots, which was associated with 50–80% reduction in sediment loss. This study demonstrates that root architecture traits can affect nutrient cycling at the agro-ecosystem level, and that integrated nutrient management strategies are necessary to avoid soil nutrient depletion.     

Increased mortality in turkeys selected for increased body weight following vaccination with a live Newcastle disease virus vaccine

Candidate male and female breeders from nine genetic lines of turkeys that were reared intermingled, with the sexes housed in different buildings on the same farm, were vaccinated with a live Newcastle disease virus vaccine (B1 type, LaSota) just prior to the commencement of egg production. In 1999, an average mortality for all lines of 5.8% occurred during the 10 days immediately following vaccination and the level of mortality varied among lines. Mortality was, in general, greater in large-bodied lines than in small-bodied lines. Affected birds exhibited gross multiple areas of focal necrosis in the liver and spleen and congestion of the heart and lungs. The percentage mortality occurring following similar vaccination in 2000 averaged 2.6 for the 10 days following vaccination and mortality was greater (P < or = 0.05) in one line (F line) than the other genetic groups and higher in females than in males. Mortality in the F line, selected for increased body weight and known to be susceptible to various diseases, averaged 15.1% for both years. Attempts failed in both years to isolate Pasteurella multocida or other bacteria. There was a positive correlation between increased body weight and increased mortality following vaccination with the live LaSota vaccine.     

Effects of body condition score (BCS) on steroid‐ and eicosanoid‐metabolizing enzyme activity in various mare tissues during winter anoestrus

The objective of this study was to determine the activity of steroid‐ and eicosanoid‐metabolizing enzymes in horses with varying BCSs. The BCSs of twenty non‐pregnant, anoestrous mares were determined prior to euthanasia, and tissue samples were collected from the liver, kidney, adrenal gland, ovary and endometrium. Cytochrome P450 1A (CYP1A), 2C (CYP2C), 3A (CYP3A) and uridine 5′‐diphospho‐glucuronosyltransferase (UGT) activities were determined using luminogenic substrates. The MIXED procedure of SAS was used to test the effect of BCS on enzyme activity and differences between tissues. Activity of CYP1A in adrenals was increased (p ≤ .05) in BCS 5 versus BCSs 4 and 6. Activity of CYP1A in the liver was increased (p = .05) in BCS 4 versus BCSs 5 and 6. Activity of CYP1A was 100‐fold greater (p < .0001) in the liver than in the adrenal, ovary and kidney. Activity of CYP2C was 100‐fold greater (p < .0001) in the liver than in the adrenal, ovary and endometrium. Activity of CYP3A was only detectable in the liver. Activity of UGT in the kidney was decreased (p = .02) in BCS 4 versus BCSs 5 and 6. Activity of UGT was threefold greater (p < .0001) in the liver than in the kidney, whereas activity of UGT was ninefold greater (p < .0001) in the kidney than in the ovary and endometrium. In general, BCS did not alter the activity of steroid‐ and eicosanoid‐metabolizing enzymes in horses. However, tissue differences in these enzymes indicated abundant hepatic metabolism in horses, which is similar to other livestock species.