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          University of Guyana               

Faculty of Agriculture & Forestry

Abstracts

Annual Review Conference

June 29 – 30, 2004

 Vol. 1   -   Number 1

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Dr. Patsy Francis, Dean

 The Faculty of Agriculture and Forestry aims to provide an environment which fosters scholarship among staff and students.  It is recognized that training, research and public service must be ongoing activities in order to fulfill our mandate in Agriculture. 

The faculty is committed to providing staff and students with opportunities which facilitate learning and stimulate independent thought.  This requires innovative and novel methods in networking and delivery of programmes in an environment of limited financial and human resources. 

Therefore our efforts at networking within Guyana, CARICOM and the developed world will be redoubled.  Research within the faculty will be both basic and applied and we welcome suggestions from stakeholders. 

The publication of these abstracts is an attempt to inform the public of the current research activities in the faculty.  These cover important areas of forestry, rice, sugar, livestock, economics and bio technology.

The Faculty takes this opportunity to recognize the assistance of all government and non government entities which supported our programmes in 2003 – 2004.  We appreciate the efforts of all the examiners, particularly subject specialists from NARI, GUYSUCO, GSA, GFC and GRDB.  We anticipate continued collaboration in 2004 – 2005.

Abstracts

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Table of Contents Continued

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Abstracts:

 Forestry 

Forestry Education In Guyana – Meeting The Challenges Of The 21^st Century

Rhonda Urlin-Knights

Over the last decade there has been a heavily felt need in the forestry sector for the establishment and reinforcement of education and training initiatives in an attempt to address some of the issues and constraints faced and to deal with changes such as those demanded by international agreements.  As stated in the National Forestry Action Plan, “All development in the forestry sector is contingent on the availability of trained people. Even at the present low level of activity in the sector, all operations are constrained, productive assets are misapplied, and human effort and economic resources are being wasted, due to the non- availability of trained personnel and training.”

The forestry sector is charged with the responsibility of sustainably managing the forest in a manner, which generates optimum benefits to the nation.   The successful achievement of this objective requires the employment of professional and technical skills, which will aid in improving quality standards, profitability and efficiency across the sector.

In addressing challenges there is need for greater collaboration between the forestry sector and tertiary forestry institutions. The development of national standards for forestry education must be effected. There is need for greater emphasis on forestry education at the secondary level. The formation of a professional body nationally is essential. Accreditation for tertiary programmes from international bodies and increased levels of research in forestry are all absolute necessities.

Keywords: Forestry sector, forestry education, stakeholders

A study of the relationship between site and growth potential for Pinus caribaea (Pine)

Anand Roopsind* and Bruce Thomerson

Plantation development in Guyana has been limited to the trials of only a few species (P.caribaea, Acacia mangium, Paulownia spp.) of which P.caribaea represents the most extensive. However these trials have been characterized by poor management after establishment.

This study revisited these P.caribaea trials (Yarrowkabra, Long Creek, Kairuni and the Bartica area) and evaluated their growth (Height and Diameter at Breast Height-DBH) in relation to various site conditions (pH, Available Phosphorus and Nitrogen, Cation Exchange Capacity, Drainage, Mean Annual Rainfall and Altitude).

A direct relationship between mean annual height increment and available phosphorus (r²= 0.9346) and Cation Exchange Capacity (r²=0.7765) was identified. The mean annual increment (m³/ha/yr) for each trial site of P. caribaea was determined by linking the mean height of each site into a yield table sourced from the Forestry Division of Trinidad and Tobago. In addition potential areas identified for future P. caribaea establishment were assigned a yield class (I-20 m³/ha, II-15.56 m³/ha, III-11.2 m³/ha, IV 6.67 m³/ha, V- 2.22m³/ha) based on this linear relationship.

The study determined that plantation establishment of P. caribaea on white sands (Regosol white quartz phase) would be uneconomical, based on the annual increment (m³/ha/yr) of the sites studied.

Key Words: Pinus caribaea, Plantation Development, Matching species with site.

 ***

A Skill Analysis Of Chain Saw Operators In Region 10, Guyana

Imole Mc Donald* and Bruce Thomerson

The aim of the study was to assess the skills of chain saw operators in Region 10 in the areas of experience, chain saw maintenance and felling techniques.

The need for vocational and technical training in the forestry sector has long been recognized. The capacity of the forestry sector to improve quality standards, efficiency and profitability is constrained by a shortage of skill chainsaw operators and in addition the need to improve practices for certification and sustainability.

Convenience sampling of chainsaw operators was conducted between Linden and Ituni utilizing a structured questionnaire as a survey instrument. The questionnaire sought to assess the skills of the operators in the following areas: age and experience, chainsaw maintenance and felling techniques.

A statistical analysis was done on the data using the Likert’s Scale (that is a numerical ranking of responses).

The results indicated that there was no correlation in the areas of total score vs. age, experience vs. age, experience vs. maintenance, experience vs. felling.

The study concluded that there was need for proper technical and vocational training programs to improve the quality, efficiency and profitability of the local forestry sector. Key Words: Felling Techniques, certification, skills training, forestry sector.

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 A Social Forestry Experience: The Guyana Context - An assessment of the perception of the responsiveness of the forest authority towards the need for social sustainability

Carlton Roberts* and Rhonda Urlin-Knights

Residents of the Hinterland communities of Guyana live in poverty while outsiders cream off their natural resources. Closure of major industrial operations exacerbates the grave unemployment situation. The victims of this economic abuse are crying out silently. 

The response of the Forest Authority to this situation demands increased capacity, higher staff motivation and revitalized efficiency. An assessment of the performance of the forest authority in this regard is gauged by the perception rating, on these issues, ascribed by the GFC staff and forest dependent individuals.  Samples were taken from both populations. Data were collected via interviews, questionnaires, and documentary analysis. Scores were generated on both the Likert and dichotomous scales. These scores were analyzed by sample means, percentages and Odds Ratio analysis. 

It was found that the approval ratings given by Technical Field Staff and Middle Managers were somewhat lower than the impressions gleaned from the Top Managers on the issues of preparedness of the Forest Authority for Social Forestry. Satisfactory approval ratings of between 40% and 60% were given by respondents from the communities on items related to:

v                Promoting a sense of responsibility towards the forest resources.

v                Enhancing the quality of community participation in forestry matters.

On the other hand, the communities gave poor ratings, of under 20%, to the contribution of the Forest Authority on items regarding:

v                Empowerment to manage the resource.

v                Improvement of economic benefits and equity.

It can therefore be concluded that the prevailing perception is that the GFC has already developed brilliant plans regarding social issues in the forestry sector; however, some of these crucial contributing factors leading towards social sustainability of forest dependent communities are yet to be addressed in meaningful ways.

Keywords:  Social Forestry, Social Issues in Forestry, Community Development,  Sustainable Livelihoods, Empowerment, Poverty Alleviation, Perceptions of Guyana Forestry Commission.

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The Structure of Home Gardens in Mahaica:  A study of their Composition and spatial variability

Alonzo Hartley*, Rhonda-Urlin Knights and Patrick Chesney

The islands of the West Indies have long been noted for their small farm subsistence agriculture. Caribbean kitchen gardens date back to slave plantation days. Kitchen gardens sustained slave workers on sugar plantations and provided the basis for future farming enterprises for slave families upon emancipation. Today these gardens continue to be a ubiquitous feature of the agricultural landscape in the Caribbean. These small units of production surrounding the Caribbean homestead are a microcosm of the farming system: the crop production knowledge and the skills of successive generations are acquired and passed on via the kitchen garden, which can be either a principal component of subsistence farming or the embryo from which a commercial agricultural or horticultural enterprise may develop.

The goal is to describe and analyse the biophysical components of home garden systems in selected areas of Guyana and how these systems can be improved in an environmentally safe manner.  The methodology of the project is divided into two phases; the first stage is diagnostic and involves the collection of baseline data. The second consists of the classification of home garden systems.

From the data obtained four layers are dominant these layers are

1.  Upper comprising mainly of coconut starting at10 m

2.  Middle comprising mainly of fruit trees e.g. Mangoes, star apples guava   between 4m-10m

3.  An intermediate layer comprising of shrubs e.g. cherries gooseberry and sourie between 1m-4m

Kitchen gardens in Guyana today still appear "crowded, confused, and haphazard".  On the other hand, one must recognized the virtues of traditional cropping practices, including mixed cropping, intercropping, and inter-culture of trees and vegetables. In the traditional pattern crops were arranged in natural "storeys": root crops occupied the subterranean level, followed by surface plants (notably beans, melons, and pumpkins), then by taller crops (such as cassava, maize, and peppers), with trees at the highest level, providing a comprehensive cover against soil erosion during heavy downpours and preventing or retarding the spread of disease and pests.  The diversity of home gardens provides some insight into the resilience and vitality of the system. All home gardens appear unique as they, on the surface, appear to follow no fixed patterns and are planted on what may appear to be the whims of the planter. But this research definitely indicates that some underlying forces drive the patterns which have evolved. The se forces may be cultural, economic, social or a heritage that has been passed on from one generation to the next.

Keywords:  Home Gardens, Spacial Diversity, Mahaica. 

*** 

An Appraisal of The Social Impacts of The Barama Company Limited on The Port Kaituma Community, N.W, Guyana.

 Urmilla Hardial* and Rhonda Urlin Knights

The study conducted was an appraisal of the social impacts of the Barama Company Limited on the Port Kaituma community, N W, Guyana.  

The study sought to establish the key social impacts that the forest company had on the remote resource dependent community. The study was intended to give new information that may be used as a guide by forestry planners in the future with a need to respond to the principles, success factor and challenges posed by company- community partnerships. The study was designed to investigate the following areas: income of the household, culture, infrastructure development and the health of residents. 

The study was conducted by the use of primary and secondary data sources. Primary data was gathered by use of a household survey administered to 30% of the population by random sampling.  

The study concludes that if the Environmental Social Impact Assessment conducted by the BCL were implemented, certain impacts would have been avoided.   

The study recommends that Government (agencies responsible) should play an active part in empowering remote communities. 

Key words: Company-community partnerships, culture, household, income, infrastructure, and social impact

*** 

Bird watching opportunities within Georgetown, Guyana -  A survey of three potential  sites 

William Trim* and Elroy Charles

South America is the fastest growing destination in nature tourism but this type of tourism is fairly new to Guyana. While there have been some overtures to avitourism in Guyana, the expeditions have been mainly to remote areas, unknown and at exorbitant cost.  This research was therefore designed to count the number of birds at 3 sites nearby (within Georgetown) and to consider the potential of birdwatching at these sites. Hence, subsequent to some informal interviews and reconnaissance, area restricted searches (similar to the rhythm of a birder) were executed to observe, count and record the number of birds sighted within 5-minute intervals of 1-hour periods during one season (the short dry season of Guyana). Overall, 110 species of birds were recorded with 82 species (the highest number) found in the University of Guyana Compound, 79 species at Georgetown Botanic Gardens and 72 species at Promenade Gardens. It turned out that all 3 sites have enough bird species to stir the interest of ornithologists, amateur and aspiring birders, researchers and biology students closer to “home” – right in their backyard – as suggested by The Royal Society for the Protection of Birds (RSPB)

Key words: Nature tourism, avitourism,  

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Potential Microbes, a Tribute to National Wealth

Prof L. Kumari

Since time immemorial, man has taken advantage of the activities of microbes, without understanding the true nature and without appreciating their role in the living process.  Plant pests and diseases management methods must be affordable, renewable, socially acceptable, and ecologically sustainable growth of agriculture, including forestry.

The plant pest and disease management methods must be affordable, renewable, socially acceptable, ecologically sustainable.  Moreover, the use of pesticides is becoming social as well as economic and environmental issue which continue to be the target of public pressures worldwide.  In this context the trend towards higher yields and quality of agricultural and forestry products create an even greater challenge for ecologically sustainable pest and disease management.

 The study of beneficial microbes now take a new turn.  Their importance in the cycle of life on this earth in the transformation of organic matter and of the essential elements, such as carbon and nitrogen are noteworthy.  The utilization of microbes in numerous industrial fermentation products, bioremediation of diversified pollutants, biotechnology and their outstanding ability to produce chemical substances (antibiotics) for combating human, animal and plant pest and disease have resulted in tremendous interest in the activities of microbes and their potential utilization for the benefit of man.

 Since microbes play an extensive role in agriculture, preliminary attempts were made to isolate soil micro-organisms in Guyana and evaluated for their biological control potential.  Attempts were also made to screen the organisms for the control of rice bug.  Microbes were isolated from dead rice bugs and characterized.  Effective microbes capable of controlling rice bugs will be subsequently characterized for field application.  Focus is given only for microbes beneficial in agriculture as microbes maintain the soil fertility, protect the crop fro pests and diseases, regulates the plant growth, provide systemically acquired resistance, and result in high yield.  Thus microbes are a tribute to national wealth. Keywords:  Beneficial microbes, sustainable agriculture, bio-remediation, biotechnology

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The effect of timing and rate of application of potassium on grain yield of rice grown under a lowland irrigation production System

Satanand Narain*. T.M Velloza and Julian Charles

Potassium (K) is an important macronutrient and is essential for good grain yields in rice.  Rice has been grown in Guyana for well over fifty years without any significant potash additions to the soil, in terms potassic fertilizers.  Soil tests done on rice soils in several rice growing areas have revealed that the levels of available K in these soils were close to or even below the critical level, that 0.2 milliequivalents per 100 soil.  Additionally, the fungal disease, Brown Spot (Bipolaris oryzae) has become more prevalent throughout the rice belt and might be indicative of K deficiency.  With this in mind, this study was implemented with a view of determining the effect of rate and timing of K application on grain yield and yield attributes, the incidence of Brown Spot, grain quality and growth factors such as plant height and the number of tillers per m².  This study was conducted at the Rice Research Station, Burma, ECD on Lichfield Clay – 42 (and Potassium was applied at three rates (0, 50 and 100 kg K₂O/ha) using six different timings of application, namely (i) All K₂O at final land preparation (ii) All K₂O at 21 DAS (iii) All K₂O at 42 DAS (iv) ½ K₂O at final land preparation + ½ K₂O at 21 DAS (v) ½ K₂O at final land preparation + ½ K₂O at 42 DAS (vi) ½ K₂O at 21 DAS + ½ K₂O at 42 DAS. 

Apart from potassium, nitrogen was applied in the form of urea at the rate of 75 kg N/ha in three splits, i.e., ¼ at 21 DAS + ½ at 42 DAS + ¼ at 60 DAS.  Phosphorus was applied in the form of TSP at the rate of 30 kg P₂ O₅ /ha at 21 DAS.

A randomised complete block design (RCBD) with a factorial treatment design was used and there were three (3) replications.  Plot sizes were 24 m² (6 × 4). Pre-germinated seeds were sown at 156.8 kg/ha and measurements were taken on plant height and tillers per m² at maturity (105 DAS), grain yield at 14% moisture content, panicle length, filled grains and unfilled grains per panicle, 1000-grain weight at 18 % moisture content, % head rice recovery and % milling yield and Brown Spot.  Duncan’s Multiple Range Test was used to separate treatment means and treatments were considered significantly different at 10% probability level.

No incidence of brown spot disease was found in the experiment. Results showed that there was no significant difference between treatments with respect to tillers/m² at maturity, 1000-grain weight, percentage head rice recovery and milling yield and grain yield at 14% moisture content. Grain yield showed an increase with increasing rates of potassium application albeit non significant at a 10% level.  Percentage plant tissue K also increased with increasing potassium rates. There was also an increasing trend in the grains/ panicle, panicle length, plant height at maturity, percentage head rice recovery and milling yield when all the K was applied at 42 DAS, when ½ was applied at land prep + ½ at 21 DAS, and when ½ was applied at land prep and ½ at 42 DAS.

This study provided sound base information as regards the effect of rate and timing of K application on the grain yield of rice, and should be repeated on a marginal soil where K deficiency has been proven via both soil and plant tissue analyses. Keywords: Rice, seed rate, potassium, yield attributes, brown spot.

***

The effect of seed rate on the grain yield of five new rice lines grown under low land irrigated production system.

 Ghansham Payman* T.M. Velloza and Julian Charles

Rice (Oryza sativa) is the second largest foreign exchange earner in the agricultural sector in Guyana.  There are many factors that affect the production of rice, one of which is the seed rate used at sowing.  Thus, the general objective of this research was to determine the appropriate seed rate for optimal grain yields of the new rice lines under a lowland irrigated production system.  The specific objectives were to determine the effect of seed rate on the following – development of the different weed species, the development of the common fungal diseases, the grain quality (%milling yield), the yield attributes (panicles length, filled and unfilled grains, and 1000- grain weight), the growth factors (plant height and tillers at maturity) and the percentage lodging of the varieties.  The experimental design used was a RCBD with a factorial treatment design.  The 5 lines used G98 22-4, G98 24-1, G98 30-3, G98 196 and G98 135.  The 4 seed rated that were used as 134.4 kg\ha, 156.8 kg\ha, 179.2 kg\ha and 201.6 kg\ha (120, 140, 160 and 180 lbs\ac).

No weeds were found in this experiment, as well as no lodging took place. It was found that seed rate had no significant effect on disease incidence, percentage head rice and total rice recovery, grain yield at 14% moisture, panicles per m² 1000-grain weight, filled and unfilled grains and plant height.  The seed rate of 134.4 kg/ha had significantly (p<0.10) longer panicle than rates of 179.2 kg/ha and 201.6 kg/ha.  In terms of the varieties, G98-135 was found to have a higher incidence of brown spot disease.  G98-135 had significantly longer panicles that the other varieties, while G98 196 had significantly shorter panicle than the other varieties.  The other yield characters did not vary with the varieties.  G98-30-3 had a significantly higher head rice recovery than G98-22-4, G98-135 while G98-196 had a significantly higher percentage total rice recovery than all other varieties.  G98-30-3 and G98-135 had significantly higher total rice recovery that G98-24-1.  G98-135 significantly out yielded the other varieties.  G98-135 and G98 22-4 were significantly taller at maturity Seed rate had no effect on the yield.

 Since the seed rates had no significant effect on the yield the most economical rate of application would be 134.4 kg ha for any of the 5 varieties.  The experiment needs to be replicated in different locations where it can be subjected to different microclimatic conditions with varying disease and weed pressures.  There is also a need to study the effects of seed-rate on the new lines in areas where there is delayed harvesting to check the lodging of the lines. 

Keywords:  Rice, Seed rate, planting density, yield attributes, lowland Irrigated production system.

***

The influence of water depth on the emergence and yield in rice

 Visan Budraj*, T.M. Velloza and Leroy Small

In Guyana, the rice crop is planted twice yearly and poor drainage is one of the major causes for the poor performance of the rice industry. Thus it is important to examine varieties to determine if any one could be used to establish an excellent crop under flooded conditions. This project was designed to determine which of the five (5) commercial varieties that are available to farmers would perform the best when grown under flooded condition.

This experiment was done in the second season of 2003-2004 season at the Rice Research Station at Burma Mahaicony.

The experiment was a randomized complete block design (R.C.B.D.) with three (3) replications, four (4) depths 0”, 2”, 4”, & 6”.

The experiment was carried out under control conditions i.e. in concrete cells in a protected area.

The cells were filled with soil taken from a field that had little history of the existing weed problem and filled with water to depth of 0,2,4 and 6 inches above the soil surface.  One hundred (100) pre-germinated seeds of the five varieties were sown in a straight line across the cell under flooded conditions.  After three (3) days data collection commenced. 

 Results indicated, the variety G-98-30-3 was the most vigorous in-terms of emergence, had the best average height at maturity, most fertile tillers, and thus was the best yielder when analytically compared to the others, giving yields of 42 bags/acre. It is therefore recommended that commercial rice farmers use this variety in order to obtain better yields thus maximizing their profits in subsequent rice crops.

Keywords: flooded conditions, pre-germinated seeds, water depth, fertile tillers

***

Effect of pH and different sources of nitrogen fertilizer on Ammonia volatilization from Whittaker clay in the laboratory

Nazir Succoor*, T.M. Velloza and Anton Dey

Urea is a dominant form of nitrogen (N) fertilizer in world agriculture (Hauck, 1984). However, problems associated with its use as a fertilizer include, among other soil loss mechanisms, the loss of N as ammonia (NH₃). The N fertilization policy of the Guyana Sugar Corporation (Guysuco) stipulates the use of both urea

and ammonium sulphate (SA) as the main sources of N for sugarcane production. These fertilizers are applied in a single dose to the surface of the soil.

Earlier studies done in Guyana (Dey and Davis, 1997) indicated low N uptake efficiency in sugarcane plants, which may have suggested a direct relationship to either one or many of the several soil N loss mechanisms. NH₃ volatilization is however not known to be a significant factor in soils with pH values below or around 6.0. Since most of the soils in Guysuco are acid (pH < 5.5) N loss by volatilization is not considered a significant factor in N losses in these soils. A laboratory study was therefore initiated to evaluate NH₃ volatilization from surface applied N fertilizers to limed (pH 5.6) and un-limed (pH 5.6) Whittaker series clay soil. NH₄-N was collected in 0.05 M H₂SO₄ solution and N losses was determined by titrating the solution with 0.1 M NaOH. A rate of 108 kg N/ha was applied in all the treatments except the control. The sample was brought to 35% moisture content.

The sources of N evaluated included urea, SA and a mixture of urea and SA. NH₃-N losses from volatilization were small for all of the N sources and were in the order urea + SA > urea > SA. A small increase in soil pH resulting from the liming of the soil resulted in small increases in NH₃ volatilization from all N sources. The maximum N losses from limed and un-limed soil were 18 and 16 ppm respectively, and represented 2.2 and 2.0 percent of applied N.

There is no urgent need for Guysuco to make any changes to the fertilizer regime with regards to application method and type of N fertilizers because N losses were not significant and as such will not impact negatively on cost.

Keywords:  Nitrogen loss, Ammonia volatilization 

***

 The efficacy of reduced tillage operation in combination with glyphosate for the control of weed in rice cultivation in Guyana

Dwarka Dipoo*, Elroy Charles and Leroy Small

 The cost of conventional land preparation represents between 20% and 25 % of the total cost of production. It is theoretically possible to replace some of the conventional operations with a total herbicide (Glyphosate 2%) to achieve with control, thus reducing the cost of the operation. 

This experiment on the efficacy of reduced tillage in combination with Glyphosate was done using rice variety G98-1-96 at the rice research station, Burma (first crop 2004). The treatments used were as follows: (1.) Conventional method (2.) Drained /reflooded @12DAS   (3.) One wet operation + Glyphosate after 10 DAS (4.) One wet operation + Glyphosate after 13 DAS (5.) One wet operation + Glyphosate after 16 DAS. These treatments were replicated 5 times using a simple randomized complete block design. 

Of all the treatments, the 3^rd method of land preparation (1 wet operation + Glyphosate after 10 DAS) proved most successful by producing the highest grain yield of an average of 35.1 bags per acre. It was also composed of the highest amount of fill grains of per panicle. The highest average plant height at maturity (81.4 cm) also came from this treatment.

From an economic point of view, the third treatment (1 wet operation + Glyphosate 2% after 13 DAS) resulted in a 45.7 % reduction in the total production cost when compared with the conventional method of land preparation. This method is highly recommended since the unit cost per input is lower and the output is higher. This shows a lot of promises to farmers and can go a very far way in enabling Guyana to be more competitive on the regional and international market.

Keywords: Conventional land preparation, herbicide, reduced tillage.

***

Ascertaining the trend of the deterioration of insect damage stalks and the impact of deterioration on juice quality of sugarcane.

 Michael Chung*, Elroy Charles and Claudette Richards-Haynes

The Diatraea spp is considered one of the major problem pests in the sugar industry in Guyana (Guysuco). The insect usually cause considerable damages by boring/tunneling the stalk, due to the larva feeding habit. In young plants the damages usually result in death “dead heart” and in older canes there maybe side shoot or “dead tops”.

These damages result in the loss of sugar (sucrose content). The method was used to determine the sucrose content that is lost due to the Diatraea Spp damages is by comparison.  The main objective behind this research was to ascertain whether any specific trend of deterioration in the sugarcane was caused by Diatraea spp

Stalks were taken from the field at different level of Diatrera damages and analysed 24 and 48 hours after burning.

The juice was extracted from the samples and analysed to determine the Brix, Polarization % and Fiber percent of the stalks. From the experiment it was observed that as the damages increased the quality of the juice was reduced despite the fluctuation of the results

The results from the analysis indicated that there was more fluctuation in the 24hrs period than the 48 hrs.  From the results obtained in this experiment the relationship between damage stalks at different levels and deterioration were not significant.

Keywords:  Diatrera, Brix, Polarization and Fiber.  

*** 

Investigating the reproductive capability and dose response of three  entomopathogenic nematodes to use as possible bio-control agents in sugarcane.

Rohit Singh*, Elroy Charles and Basil Dasrat

 Identification of a biological control agent is considered the most appropriate direction of focus to effect control on Diatraea centrella a sugarcane pest in Guyana. The successful species must be able to survive native environmental conditions, successfully reproduce within the environment and at the same time be aggressive enough to efficiently seek out and parasitise host larvae. A comparative laboratory evaluation of the reproductive capability of four Entomopathogenic Nematodes was done on Diatreae centrella larvae as hosts. Each species of EPN and a control were considered treatments, replicated five times and inoculated at a rate of 200 infective juveniles/ml (IJs/m). After death of host larvae, cadavers were transferred to White traps and IJs counted at 48 hrs intervals until IJs release ceases or for 100days. Statistical analyses (as for CRD) revealed that the ability of Steinernema abbasi  to infect and kill D. centrella larvae is comparable to Steinernema riobrave and Heterorhabditis bacteriophora but it is superior to Steinernema carpocapsae. It has also shown that S. abbasi, like the former two can survive and successfully reproduce within the cadaver for a full 100 days. IJs yields per 48 hrs period and overall IJs yields were also comparable to H. bacteriophora and S. riobrave but superior to S. carpocapsae. To determine the most effective dosage of a formulation containing the species, a dose response test was also done. Five treatments were inoculated at 8 rates and replicated 5 times. Three days after inoculation, whether dead or alive, all inoculated larvae were dissected and IJs released, counted. A regression analysis revealed that there is a moderately strong relationship between the two and as the dosage increased so did the release of IJs up to a dosage of 300IJs/ml at which level the number of IJs released begins to decline. The most infective species therefore are S. riobrave, H. bacteriophora and S. abbasi and their most effective dosage is 300IJs/ml

Keywords: Entomopathogenic Nematodes, biological control, Diatreae centrella, infective juveniles

***

Evaluation of reduced Tillage operations and their effect on sugarcane growth and yields.

Abasola Simon*, T.M. Velloza, and Norman Friday

The Guyana coastal plains represent a faction of the continuous low and wetlands, which extend from the mouth of the Amazon river to the Orinoco delta.  The soils have been developed in alluvial deposits of marine and river origin (Smith, 1983).  The majority of the soils have high clay contents with properties of high moisture retention (Table I).  In recent times, machine use in the Guyana Sugar Corporation (Guysuco) has been emphasized.  However, with an average annual rainfall on the coast of between 1900 and 2300 mm and the clayey nature of the soils, it is sometimes very difficult to operate machines in-field following even moderate amounts of rainfall.

Tillage in Guysuco usually consists of several passes with a plough and/or harrow as primary tillage implements over the entire bed width.  Such tillage operations are costly, and significantly contribute to the overall high cost of sugar production in Guyana.

Promising results obtained from previous work using the Howard Paraplow (itself considered a reduced tillage implement) on coastal clay soils in Guyana (Dey et al, 1997) prompted Guysuco to look for more cost effective tillage operations that can sustain cane yields and reduce overall cost of production.  Based on these results it was decided to investigate more thoroughly minimum tillage operations as part of standard land management practices.  To this end, a trial encompassing minimum tillage operations was established at La Bonne Intention (LBI) estate location for direct comparison with the standard full width tillage treatment.  The four tillage operations being evaluated are (i) no tillate (NT), (ii) strip tillage (ST), (iii) reduced tillage (RT), and (iv) conventional full width tillage (CT).

The operational cost per hectare for the NT, ST, and RT were lower than the CT system, with the NT being the lowest.  All minimum tillage operations showed better machine efficiency than for the CT system.  Tiller population (at 11 weeks) and cane girth and height were similar for all the treatments.  Root density fluctuated between treatments at the various depths.  Reduce tillage had the lowest soil bulk densities and resistance in the top and subsoil while strip tillage had the highest.  Breakdown on soil characteristics and cost parameters, RT seems to be an alternative to CT but final judgement will have to wait on yield assessment.  

Keywords:  No tillage, reduced tillage, strip tillage

 ***

Evaluation of the performance of broilers fed a multienzyme complex Avizyme^® 

and its effects on VFA production and utilization

 Patsy Francis

One hundred eighty, male, one-day-old, Hubbard broiler birds were randomly assigned to three levels of  Avizyme^® in rye and corn-based diets to assess changes in fermentation, water consumption and their effect on performance and microbial population in the gastrointestinal tract.  Enzyme addition water to feed consumption ratio in rye diets (P  0.03), reduced feed to gain ratio and increased cumulative weight gain (P  0.03) more effectively in rye than in corn diets.  Gastrointestinal determinations for total lactobacilli and pathogenic cliostridia were consistently higher in birds fed rye diets (P  0.02), but salmonellae were only higher in week six.  Enzyme addition reduced total colony forming units in the caeca but not in the ileum or jejunum of birds on both grain types (P  0.02) with clostridia declining at a greater rate in the corn diets.  Acetate concentration was higher and increased with the addition of Avizyme^®   in rye diets (P  0.0001), but neither grain source nor enzyme addition affected the concentrations of isobutyrate, isovalerate or propionate in digesta samples.  The addition of Avizyme^®   generates more digestible and fermentable substrates which improves bird performance, water intake and may reduce profileration of some opportunistic pathogens.

Keywords:  Avizyme, rye, microorganisms, fermentation, performance

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An Evaluation Of Chemical Changes In Poultry Litter Treated With Calcium Carbonate And Aluminium Sulphate. 

Rayon King* and Patsy Francis

 The breakdown of uric acid in poultry litter produces the gas ammonia which is detrimental to birds and farm workers. Increased feed conversion, mortality and reduced weight are associated with ammonia in broiler houses. The objective of this study was to evaluate the economics of treating the litter in broiler houses with Aluminium Sulphate (alum) and a Aluminium Sulphate and limestone combination. One hundred and eighty birds were randomly assigned to six experimental treatments in a CRD with 10 birds per replicate and 3 replicates per treatment. Ammonia volatilization, broiler performance and the chemical changes were evaluated. The treatments were as follows: Treatment 1: 60g Al₂So₄/kg litter, Treatment 2: 40g Al₂So₄/kg litter, Treatment 3: 20g Al₂So₄/kg litter, Treatment 4: 20 kg lime + 20 kg Al₂So₄/kg litter, Treatment 5: 30 kg Lime + 10 kg Al₂So₄/kg litter, Treatment 6: Control-0 Alum + 0 Limestone. Bird performance was monitored and litter was sampled every ten days.

Mortality, litter pH, litter total nitrogen which is a measure of the ammonia trapped in the litter (keldjhal and Nessler method) and litter moisture were evaluated. The environmental conditions prevailing at the time of the study were also documented. This included  temperature, relative humidity and wind speed. The results of the study indicated that at  (P< 0.05),  litter pH of the control was significantly higher than all of the other five treatments, with litter treated with  60g Al₂ SO₄ having the lowest pH. The total nitrogen of treatments 1, 2, 4 and 5 were not significantly different from each other but they were significantly different than that of the control (P <0.05). Bird weight did not differ among treatments 1, 2, 4 and 5 but with the exception of treatment 5 they were significantly different from the control.  Treatment 3 did not differ from the control.  Results of this study indicate that treatment 1: 60g of Alum/kg. litter was the most effective in ensuring low litter pH, trapping more ammonia and subsequently resulting in higher bird weight. Treatment two however is the most cost effective.

Keywords: Broilers, litter treatment, aluminum sulphate, limestone, vocalization

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The effect of feeding multi-nutritional blocks on growth parameters and  carcass quality of rabbits

 Kelvin Pelle* and Patsy Francis

Fifteen crossbred rabbits were randomly allocated in a CRD experimental design to six groups   (3 groups of three and 3 groups of 2) and caged separately. The cages were randomly assigned to two dietary treatments; (treatment 1) ad libitum commercial rabbit pellets and (treatment 2) ad libitum multinutritional (m.n.) blocks made with Leucaena leucocephala  Rabbits were fed over a six week period. The objectives were to compare the effect of the two dietary treatments on feed consumption, average daily gain (ADG), feed conversion ratio (F.C.R.) and carcass quality.   No obvious health problem was encountered during the experiment. The parameters measured were feed intake and live weight gain. Carcass weight and organoleptic properties were also assessed. Chicken was added as a third treatment for the organoleptic test for comparison to a standard meat. Average feed intake was the highest with commercial pellet (23.82 g) but 52.35% lower for m.n. blocks (11.35 g). There was no significant difference in feed consumption, dressing % and dissectible fat (p<0.05). ADG was significantly different (P<0.05) for treatments, 24.01g and 11.27g respectively. FCR for commercial pellets was significantly lower (4.05:1) compared to m.n. blocks (6.43:1). Treatment 1 received higher scores on the organoleptic evaluation than both treatment 2 and chicken (81, 75.9 and 79 respectively) and was ranked a higher quality meat (86 to 72 and 81 respectively). The feed cost per unit weight gain was 42% lower for m.n. blocks (EC$3.51) than for pellets (EC$6.07).  It is concluded that feeding m.n. blocks would be cheaper than feeding commercial pellets but that ADG, FCR and carcass quality would be affected.  Keywords: Nitrogen loss, Ammonia volatilization.

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Effects Of Ensiling Sugarcane Bagasse And Brewers Grains On Nutrient Composition And Feeding Value

 Shenella Benjamin* and Patsy Francis

The feeding value of sugarcane bagasse and brewers’ grain silage was evaluated in dairy heifers.

Sixteen hundred pounds of bagasse and brewers grain were collected and mixed together on a 1:1 ratio, using fifteen pounds (15lbs) of diluted molasses to every hundred pounds (100lbs) mixture of bagasse and brewers grain. Immediately after mixing they were place into salt bags lined with 38’x 50’garbage bags. The materials were compacted and the bags sealed. These materials were allowed to ensile for four different periods 45,60,75,90 days (silage and concentrates fed at the end of each period of ensiling is regarded as the different treatments in this experiment (p45, p60, p75, p90, crtl45.crtl60, ctrl75, ctrl90). After the various periods of ensiling had elapsed the bag were opened, spoilage were removed and the proximate composition of samples were determined.

Six cross breed heifers of weighing approximately138.64 to 244 kg were selected for the trial. These heifers were divided into two groups (animal 1,3,5) in the first group and (animal 2,4,6) in the second. These animals were kept under a semi intensive system, where all animal were allowed to graze a mix forage sward pasture for eight hours each day and housed in individual cubicle of 20 ft² The first group of animals were fed the different kinds of silages while the second group were fed wheat middling and copra meal concentrates. Feeding of the different treatments last for one weak and animals were weighed before and after each treatment. The daily intake of animals under different treatments was recorded.

At (P=0.05) level of significance daily gains of animals when fed p90 and ctrl90 was 19 which not significantly different from those fed ctrl45 which was 17.667, but was significantly from daily gains of animals when fed p45, p60.which was 12.667 lb and 12.333 lb but p45 and p60 were not significantly different from ctrl60 in daily gains, value (11.00).

However  feed intake at (P=0.05) p75 had the highest level of intake by animals (6.333lb) which was significantly different from p60, ctrl75, ctrl90, ctrl45, ctrl60, and p90.

For the proximate analyses carried out on the silages and the concentrate mix of copra meal and wheat middling it was found that the nutrient composition (dry matter, crude protein, crude fiber, crude fat and ash) of the concentrate was significantly different at (P <0.05) from that of silage at all of the different ensiling periods. 

However based on average daily gains and feed intake of animals it can be concluded that sugar cane bagasse and brewers grain silage can be used as a supplement for the feeding of  dairy heifers.

Key words:  Dairy heifers, ensiled bagasse, brewers grains

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 An evaluation of the effects of tapeworms and roundworms on growth

parameters of sheep

Farhaan Uthman*, Patsy Francis and Ariston Lyte

The objectives of the study were to determine whether the presence or absence of larvae and eggs in the faecal content of sheep had any correlation with farm, age and sex of sheep observed. The study also identified the age group most affected, observing whether or not sanitary conditions affect sheep kept under different conditions.

Two farms were examined, (NARI and Chung) and a total of forty-eight (48) sheep were used, with twenty-four  (24) sheep being used on each farm (twelve (12) adults and twelve (12) juveniles). The weights of and faecal samples from these animals were taken over a three-month period. These samples were then examined using the Helmento Ovoscopic Sedimentation method and Floatation Method (Mc Master method). Evaluations were done to determine if the presence of  larvae or egg were associated with  the sex of the animals, age of the animals, sanitary conditions of the farms, and weight gains. Analysis of weight gain was done using weight as a Covariate with Ls means-separation, over a period of one hundred and forty four days. Samples were taken at intervals of eighteen days. An examination of the replicate, weight, farm, group and the farm by group indicated significance at day one. Replicates and farm values were 0.045 and 0.076 respectively. There was a significance in  weight gain (P= 0.0436) at day  eighteen. There was also a farm by group interaction (P= 0.01).  On sample day three, there was no significant difference in replicates, weight gain, farm, and farm by group.

For the analysis of weight gain using weight as covariate with LS means-separation, in farm samples on day one, there was no significant difference between the two farms.  This

trend was observed throughout the experimental period. The total gain by Farm was also not significant.  This study indicates that juveniles across farms were more affected than adults with no significant difference in weight gain.

Keywords: Sheep, Weight Gain, Tapeworms, and Roundworms

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 The Supply Response of Farmers’ production to the price of Beef on the domestic market of Guyana.

 Arnold De Mendonca

The study indicates that beef farmers in Guyana operate on a low input – low output basis with the majority of farmers being part time and their enterprises being undertaken for the purpose of supplementing income.  The study also indicates that the industry is not ready as a whole for the export of carcasses.  

Sixty-one (61) beef-producing farmers in the Region 5 area were randomly selected and interviewed using a structured questionnaire.  The questionnaire sought to determine farmer-profiles, production and marketing practices, access to credit and other constraints.  Knowledge of farmers operating in the industry and their perceptions of future price and possible responses towards further investment plans to increasing the supply of beef if prices increased satisfactorily.  The data collected were analyzed using simple analytical techniques.  

The study identified factors that were related to farmers’ perceptions and response to increased prices.  Farmers’ responses to increased prices were not constrained by farm related, socio-economic, cultural, environmental or personal factors however, the study found responses were constrained by the access to credit and availability of adequate lands for increased production.  The study also found that the current slaughter rates for all classes of cattle were contributing to the decline of the national herd.  

The study concluded and recommended that current production; slaughtering and marketing activities did not predispose the industry to a sustainable export trade.  It is necessary that research and extension training activities focus on making the production system intensive and more competitive.  Additionally there should be the infusion of new breeds in the industry to increase carcass quality.

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Faculty of Agriculture & Forestry:

Dr. Patsy Francis                                  Dean

Dr. T.M. Velloza                                   Assistant Dean   

Mr. Elroy Charles                                 Lecturer

Mrs. Rhonda Urlin-Knights               Lecturer

Mr. Bruce Thomerson                         Lecturer

Mr. Arnold De Mendonca                  Lecturer

UGBC                                                   Faculty of Social Sciences

Dr. P.Thakur                                             Mr. Leslie Simon

Dr. L Kumari                                          Faculty of Natural Sciences

                                                               Mr.  Calvin Bernard

NARI                                                      GSA

Dr. Patrick Chesney                             Ms. Lynette Cunha

Mr. Cleveland Paul                              Mr. Compton Hinds

Mr. Egbert Ralph                                  Mr. Owen Bovell

Dr. Robin Austin

Mr. Juan Solomon

NDDP                                                    GDDP

Dr. Nicholas Waldron                         Mr. Kelvin Craig

GFC                                                        WWF

Dr. Racquel Thomas                            Dr. Gary Clarke

Ms. Trudy Clarke                                

Ms. Yolanda Hawker

GUYSUCO                                            GRDB

Mr. Anton Dey                                     Mr. Julian Charles

Ms. Claudette Richards-Haynes       Mr. Leroy Small

Ms Lisa Shrivaj

Mr Basil Dasrat

IICA                                                       IWOKRAMA

Mr. Cromwell Crawford                       Dr. David Singh

Rural Women’s Network                  Guyana forum for Youth in Agriculture

Ms. Bibi Andrews                                Ms. Dillon Husbands

MFCL                                                    Private

Mr. Errol Luke (CCLO)                        Mr. John Browman (Former Dean, Fac of Agri))

Dr. Vernon Mc Pherson  (Part time Lecturer)

For More Information Contact

Dr. Patsy Francis, Dean

Faculty of Agriculture & Forestry

University of Guyana

Turkeyen Campus,

PO Box 101110, Georgetown, Guyana

Tel: 222-5424, 3599

Email:ugfacagri@yahoo.com

Website:  http://www.uog.edu.gy

 Compiled & Designed By

Arnold De Mendonca

Lecturer.

  Faculty of Agriculture & Forestry University of Guyana

Email: demendonca_arnold@yahoo.com

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