Papers by Chaney St.Martin
Environmental Technology, 2014
6 Trinidad and Tobago 7 High-rate composting studies on green waste, i.e. banana leaves (BL) and ... more 6 Trinidad and Tobago 7 High-rate composting studies on green waste, i.e. banana leaves (BL) and lawn clippings (LC) 8 were conducted in 0.25 m 3 rotary barrel composters to evaluate and model changes in key 9 physico-chemical parameters during composting. Time to compost maturity and antagonistic 10 effects and relationships of composts against Pythium ultimum were also investigated. Higher 11 temperatures were achieved in LC compost (LCC) which did not translate to higher total organic 12 carbon (TOC) loss but resulted in lower carbon to nitrogen ratio (C:N) and a more mature 13 compost. With the exception of electrical conductivity (EC), net decreases were observed in pH, 14 TOC and C: N across compost types. Total Kjeldahl nitrogen (TKN) showed a net increase in 15 LCC and a net decrease in BLC. With the exception of TOC and pH, results showed that 16 compost type and time had a significant effect on the respective TKN, EC and C: N models. 17 Compost temperature and TOC were best described by the critical exponential and rectangular 18 hyperbola, respectively. Whereas, TKN, C: N and pH were described using double Fourier 19 functions and EC using Fourier functions. Composts achieved maturity within 19 days and 20 significantly inhibited mycelial growth of P. ultimum. Bacterial population was positively related 21 to mycelial growth inhibition (GI) across compost types whereas total microbial population had a 22 positive relationship with GI in LCC. Evidence suggests that multiple groups of microorganisms 23
Yet another attempt is being made in the Caribbean to modernize the agriculture sector through th... more Yet another attempt is being made in the Caribbean to modernize the agriculture sector through the adoption of technologies that have the potential of increasing the production and productivity of the vegetable sub-sector. The recent re-introduction of Greenhouse Technologies has once again generated heightened interest across the region. As in the past, several drawbacks have impeded full exploitation of the many advantages of this technology. This paper reviews the status of the sector in Trinidad and Tobago and Jamaica focusing on characterizing the various types of structures being used, crop management practices, the major constraints faced by producers, and the level of training. 16 farmers in Trinidad and Tobago and 22 Greenhouse Vegetable Producers in Jamaica were surveyed using detailed questionnaires. The data were presented as descriptive statistics. The results showed that the greenhouse vegetable producers rated the lack of information and adequate finance, insufficient...
Yet another attempt is being made in the Caribbean to modernize the agriculture sector through th... more Yet another attempt is being made in the Caribbean to modernize the agriculture sector through the adoption of technologies that have the potential of increasing the production and productivity of the vegetable sub-sector. The recent re-introduction of Greenhouse Technologies has once again generated heightened interest across the region. As in the past, several drawbacks have impeded full exploitation of the many advantages of this technology.
There is a paucity of information on the efficacy of nutrient amendments made from readily avail... more There is a paucity of information on the efficacy of nutrient amendments made from readily available local
material on seedling quality. The objectives of this study were to evaluate the combinatory effects and
relationships of compost tea, fertiliser, and Glomus intraradices inoculated-substrate on tomato seedling quality
as defined by fresh and dry biomass, root to shoot ratio, length of root and stem, and selected root system
architecture parameters . The factorial designed assays consisted of tomato sown in autoclaved or non-
autoclaved peat-based substrates, which was either fortified (PM) or not fortified (PNM) with the
endomycorrhizal fungi, G. intraradices, to which fertiliser only (FO), unfiltered compost tea + fertiliser (UCT +
F), or filtered compost tea + fertiliser (FCT + F) were applied to these substrates. With the exception of the
positive effect of FCT + F on leaf area, the application of compost teas + fertiliser to PM substrates (non-
autoclaved or autoclaved) did not provide any additional benefits compared to FO treatment. However, FO
applied to PM or autoclaved substrates resulted in lower or lowest seedling growth (root and shoot) compared to
UCT + F applied to PM substrates. The application of FCT + F, which had similar nutrient supplying capacity
as UCT + F but without microorganisms, to PM substrates, resulted in significantly lower seedling growth.
Roots were not colonised with G. intraradices and results suggest that increased seedling growth was related to
the biological properties of the UCT and non-autoclaved substrates. Network width to depth ratio was the most
important factor affecting shoot growth. Quality of tomato seedlings resulting from non-autoclaved PM and
PNM substrates applied with UCT + F was comparable.
Keywords: compost, Solanum lycopersicum, nutrient amendment, mycorrhiza, soil-less substrate, seedling
performance
Maturity, which significantly affects the potential use of compost as a peat alternative substrat... more Maturity, which significantly affects the potential use of compost as a peat alternative substrate, or substrate component, is difficult to measure, and laboratory-based testing methods are generally unattractive to farmers, due to cost and time delays. The accuracy of relatively simple, quick, and inexpensive plant-exclusive and -inclusive methods for evaluating maturity of rotary barrel composted banana leaf (BL) and lawn clipping (LC) for use as seedling starter and transplant substrates for production of tomato (Solanum lycopersicum L.) and sweet pepper (Capsicum annum L.) seedlings were investigated. Nine substrates were tested: BL or LC compost mixed at rates of 20%, 50%, 80%, and 100% (by volume) with 0% compost; that is, PRO-MIX ‘BX’/Mycorise PRO (Premier Horticulture Ltd., Dorval, Canada) alone as the control. Compost rate affected substrate electrical conductivity (EC), which, in contrast to seedling emergence, survival, and aerial growth, increased with increasing compost inclusion rate. Compost maturity test methods produced no, low, and high levels of phytotoxicity results. Neither BL nor LC compost consistently had a greater phytotoxic effect; instead, the effect seemed to be crop specific. Leaf area was more sensitive to compounds present in the compost than root growth, and EC was the most important factor inhibiting seedling emergence, survival, and root length of tomato and sweet pepper. Microorganisms indigenous to LC compost likely suppressed the positive stimulatory effects of compost extracts diluted at 1:20 v/v on sweet pepper germination and root elongation. Solvita (Woods End Research Laboratory, Inc., Mt. Vernon, Maine), a rapid (4 h) compost maturity test, in combination with a seedling growth assay may be the simplest, least costly, and most useful method to evaluate compost use potential. PRO-MIX ‘BX’/Mycorise PRO amended with BL or LC compost at 1:5 v/v is a good alternative to peat-based substrates for use as a seedling starter and transplant substrate for production of sweet pepper seedlings.
High-rate composting studies on green waste, i.e. banana leaves (BL) and lawn clippings (LC), wer... more High-rate composting studies on green waste, i.e. banana leaves (BL) and lawn clippings (LC), were conducted in 0.25-m3 rotary barrel composters to evaluate and model changes in key physico-chemical parameters during composting. Time to compost maturity and antagonistic effects and relationships of composts against Pythium ultimum were also investigated. Higher temperatures were achieved in LC compost (LCC), which did not translate to higher total organic carbon (TOC) loss but resulted in lower carbon to nitrogen ratio (C:N) and a more mature compost. With the exception of electrical conductivity (EC), net decreases were observed in pH, TOC and C:N across compost types. Total Kjeldahl nitrogen (TKN) showed a net increase in LCC and a net decrease in BLC. With the exception of TOC and pH, the results showed that compost type and time had a significant effect on the respective TKN, EC and C:N models. Compost temperature and TOC were best described by the critical exponential and rectangular hyperbola functions, respectively. Whereas TKN, C:N and pH were described using double Fourier functions and EC using Fourier functions. Composts achieved maturity within 19 days and significantly inhibited the growth of P. ultimum. Bacterial population was positively related to growth inhibition (GI) across compost types, whereas total microbial population had a positive relationship with GI in LCC. Evidence suggests that multiple groups of microorganisms contributed to GI through antibiosis and competition for resources. Composts were determined to be suitable for use as components of plant growth substrates based on compost maturity indices.
Biological Agriculture & Horticulture, Jan 1, 2012
Studies were undertaken to determine the effects and relationships of compost type, aeration, and... more Studies were undertaken to determine the effects and relationships of compost type, aeration, and brewing time on compost tea properties, phytotoxicity, and efficacy in inhibiting growth of Pythium ultimum in vitro. The effect of compost tea on dry matter of tomato and sweet pepper seedlings cultivated on compost-amended substrate was also investigated. Compost type, aeration, and brewing time significantly affected the microbial and chemical properties of compost teas made from banana leaf (BLC) and lawn clipping (LCC) composts. Both aerated and nonaerated compost teas made from BL and LC composts significantly inhibited mycelial growth of P. ultimum. However, growth inhibition (GI) levels were significantly higher in compost teas produced from LCC. Aerating compost tea (ACT) did not consistently result in higher GI levels across compost types. Neither did increasing brewing time beyond 18 h for ACT and 56 h for nonaerated compost tea (NCT). Across all ACTs, yeast population was positively related to GI whereas bacterial population had a positive relationship with GI across all NCTs. Evidence suggests that multiple groups of microorganisms contributed to GI through antibiosis and competition for resources. All compost teas stimulated seed germination of tomato and root growth in sweet pepper. However, NCTs brewed for 56 h using LCC or BLC, and ACT produced from BLC brewed for 18 h, significantly reduced seed germination of sweet pepper. Application of NCT brewed for 168 h made from BLC significantly increased total dry matter of tomato seedlings by 122% compared with the control.
Uploads
Papers by Chaney St.Martin
material on seedling quality. The objectives of this study were to evaluate the combinatory effects and
relationships of compost tea, fertiliser, and Glomus intraradices inoculated-substrate on tomato seedling quality
as defined by fresh and dry biomass, root to shoot ratio, length of root and stem, and selected root system
architecture parameters . The factorial designed assays consisted of tomato sown in autoclaved or non-
autoclaved peat-based substrates, which was either fortified (PM) or not fortified (PNM) with the
endomycorrhizal fungi, G. intraradices, to which fertiliser only (FO), unfiltered compost tea + fertiliser (UCT +
F), or filtered compost tea + fertiliser (FCT + F) were applied to these substrates. With the exception of the
positive effect of FCT + F on leaf area, the application of compost teas + fertiliser to PM substrates (non-
autoclaved or autoclaved) did not provide any additional benefits compared to FO treatment. However, FO
applied to PM or autoclaved substrates resulted in lower or lowest seedling growth (root and shoot) compared to
UCT + F applied to PM substrates. The application of FCT + F, which had similar nutrient supplying capacity
as UCT + F but without microorganisms, to PM substrates, resulted in significantly lower seedling growth.
Roots were not colonised with G. intraradices and results suggest that increased seedling growth was related to
the biological properties of the UCT and non-autoclaved substrates. Network width to depth ratio was the most
important factor affecting shoot growth. Quality of tomato seedlings resulting from non-autoclaved PM and
PNM substrates applied with UCT + F was comparable.
Keywords: compost, Solanum lycopersicum, nutrient amendment, mycorrhiza, soil-less substrate, seedling
performance
material on seedling quality. The objectives of this study were to evaluate the combinatory effects and
relationships of compost tea, fertiliser, and Glomus intraradices inoculated-substrate on tomato seedling quality
as defined by fresh and dry biomass, root to shoot ratio, length of root and stem, and selected root system
architecture parameters . The factorial designed assays consisted of tomato sown in autoclaved or non-
autoclaved peat-based substrates, which was either fortified (PM) or not fortified (PNM) with the
endomycorrhizal fungi, G. intraradices, to which fertiliser only (FO), unfiltered compost tea + fertiliser (UCT +
F), or filtered compost tea + fertiliser (FCT + F) were applied to these substrates. With the exception of the
positive effect of FCT + F on leaf area, the application of compost teas + fertiliser to PM substrates (non-
autoclaved or autoclaved) did not provide any additional benefits compared to FO treatment. However, FO
applied to PM or autoclaved substrates resulted in lower or lowest seedling growth (root and shoot) compared to
UCT + F applied to PM substrates. The application of FCT + F, which had similar nutrient supplying capacity
as UCT + F but without microorganisms, to PM substrates, resulted in significantly lower seedling growth.
Roots were not colonised with G. intraradices and results suggest that increased seedling growth was related to
the biological properties of the UCT and non-autoclaved substrates. Network width to depth ratio was the most
important factor affecting shoot growth. Quality of tomato seedlings resulting from non-autoclaved PM and
PNM substrates applied with UCT + F was comparable.
Keywords: compost, Solanum lycopersicum, nutrient amendment, mycorrhiza, soil-less substrate, seedling
performance