San Rafael del Norte, Nicaragua

National University of Agriculture at Nicaragua

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San Rafael del Norte, Nicaragua

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Mendieta-Araica B.,National University of Agriculture at Nicaragua | Sporndly R.,Swedish University of Agricultural Sciences | Reyes-Sanchez N.,National University of Agriculture at Nicaragua | Sporndly E.,Swedish University of Agricultural Sciences
Livestock Science | Year: 2011

The effect on milk yield, milk composition and ration digestibility of using Moringa leaf meal as a protein source in concentrate given to six lactating dairy cows fed a basal Elephant grass diet was tested using a changeover 3×3 Latin square design, replicated twice. The basal Elephant grass diet and a concentrate containing 20% soybean meal was compared with a concentrate where the soybean meal was replaced with the same amount of Moringa leaf meal. In the third diet commercially available components were used to compose an "Iso" concentrate with the same energy and protein content as the concentrate containing Moringa leaf meal. The intake of dry matter, organic matter, neutral detergent fibre and acid detergent fibre did not differ significantly between treatments and averaged 15.4, 13.9, 7.2 and 5.9kgday-1, respectively, while crude protein (CP) intake was higher (P<0.001) for the soybean meal treatment compared to the other treatments, 1.7 and 1.2kg CP day-1, respectively. The treatments did not differ with regard to digestibility with the exception of CP digestibility, which was significantly higher in the soybean meal treatment compared with the Iso concentrate, 0.70 and 0.62, respectively. Mean daily milk yield was significantly higher (P<0.05) when cows were given soybean meal compared with both Moringa leaf meal and the optimized concentrate, 13.2, 12.3 and 12.1kgday-1, respectively. There was no significant difference between treatments in either the milk composition, or the organoleptic characteristics of the milk. The conclusion is that locally produced Moringa leaf meal can, at the same protein and energy levels, successfully replace the commercial constituents in concentrate for dairy cows. © 2010 Elsevier B.V.


Blandon-Diaz J.U.,National University of Agriculture at Nicaragua | Blandon-Diaz J.U.,Swedish University of Agricultural Sciences | Forbes G.A.,International Potato Center | Andrade-Piedra J.L.,CIP | Yuen J.E.,Agricultural University of Ecuador
Plant Disease | Year: 2011

In this study, the adequacy of the late blight simulation model LATEBLIGHT (version LB2004) was evaluated under Nicaraguan conditions. During 2007 to 2008, five field experiments were conducted in three potato-production regions in northern Nicaragua. Two susceptible ('Cal White' and 'Granola') and one resistant ('Jacqueline Lee') potato cultivars were evaluated without use of fungicides and with three application intervals (4, 7, and 14 days) of the fungicide chlorothalonil. The simulation model was considered adequate because it accurately predicted high disease severity in susceptible cultivars without fungicide protection, and demonstrated a decrease in the disease progress curves with additional fungicide applications, similar to that observed in the plots. The model also generally predicted inadequate fungicide control, even with a 4-day spray interval, which also occurred in the field. Lack of adequate fungicide protection would indicate the need for cultivars with higher levels of durable resistance, and that farmers should consider more effective fungicides applications (higher dosages or different chemistries) if susceptible cultivars are used. © 2011 The American Phytopathological Society.


Mendieta-Araica B.,Swedish University of Agricultural Sciences | Sporndly E.,Swedish University of Agricultural Sciences | Reyes-Sanchez N.,National University of Agriculture at Nicaragua | Salmeron-Miranda F.,National University of Agriculture at Nicaragua | Halling M.,Swedish University of Agricultural Sciences
Agroforestry Systems | Year: 2013

The effect of different planting densities (100,000 and 167,000 plants ha-1) and levels of nitrogen fertilization (0, 261, 521, and 782 kg N ha-1 year-1) on biomass production and chemical composition of Moringa oleifera was studied in a split-plot design with four randomized complete blocks over 2 years with eight cuts year-1 at the National Agrarian University farm in Managua, Nicaragua (12°09′30. 65″N, 86°10′06. 32″W, altitude 50 m above sea level). Density 167,000 plants ha-1 produced significantly higher total dry matter yield (TDMY) and fine fraction yield (FFDM), 21. 2 and 19. 2 ton ha-1 respectively, compared with 11. 6 and 11 ton ha-1 for 100,000 plants ha-1. Growth rate in 167,000 plants ha-1 was higher than in 100,000 plants ha-1 (0. 06 compared with 0. 03 ton ha-1 day-1). Average plant height was 119 cm irrespective of planting density. Fertilization at the 521 and 782 kg N ha-1 year-1 levels produced the highest TDMY and FFDM in both years of the study and along all cuts. The interaction between cut and year was significant, with the highest TDMY and FFDM during the rainy season in the second year. Chemical composition of fractions showed no significant differences between planting densities. Significantly higher crude protein content was found in the coarse fraction at fertilizer levels 521 and 782 kg N ha-1 year-1 (87. 9 and 93. 7 g kg-1 DM) compared with lower levels. The results indicate that Moringa can maintain up to 27 ton ha-1 dry matter yield under dry tropical forest conditions over time at a planting density of 167,000 plants ha-1 if the soil is regularly supplied with N at a level of approximately 521 kg ha year-1 in conditions where phosphorus and potassium are not limiting. © 2012 Springer Science+Business Media B.V.


Castro-Marin G.,National University of Agriculture at Nicaragua | Tigabu M.,Swedish University of Agricultural Sciences | Gonzalez-Rivas B.,National University of Agriculture at Nicaragua | Oden P.C.,Swedish University of Agricultural Sciences
Tropical Ecology | Year: 2011

We examined the optimal temperature and light requirements for seed germination of Bombacopsis quinata, Cordia alliodora, Lysiloma divaricatum and Tabebuia rosea and establishment of B. quinata, C. alliodora and T. rosea seedlings planted under different light conditions. Seeds of L. divaricatum germinated rapidly and to a large extent at all constant temperature regimes (15-35 °C) both in light and darkness. Exposure of seeds to alternating temperatures of 20/15 °C resulted in 58% germination in darkness and 62% in light. C. alliodora and T. rosea seeds germinated equally well at constant temperature regimes ranging from 20 °C to 35 °C in light and darkness. Exposure to alternating temperatures (20/15 °C) resulted in higher germination for seeds of C. alliodora in dark than in light, while it inhibited the germination of T. rosea seeds. Seeds of B. quinata incubated at 20 °C and 25 °C in light and 20 °C in darkness exhibited the highest germination while exposure to alternating temperatures completely arrested germination in this species. Survival of C. alliodora seedlings was higher on open and partially-open sites than on the site under closed canopy. B. quinata had the lowest survival while T. rosea had the highest on the open site. The findings are discussed in relation to the restoration of abandoned sites. We concluded that while C. alliodora and T. rosea could potentially serve as framework species for the restoration of degraded and/or abandoned sites, B. quinata does not meet the requirements of a framework species for restoring degraded sites in drier regions. © International Society for Tropical Ecology.


Trognitz B.,AIT Austrian Institute of Technology | Trognitz B.,Growth Science | Cros E.,CIRAD - Agricultural Research for Development | Assemat S.,CIRAD - Agricultural Research for Development | And 6 more authors.
PLoS ONE | Year: 2013

The sensory quality and the contents of quality-determining chemical compounds in unfermented and fermented cocoa from 100 cacao trees (individual genotypes) representing groups of nine genotype spectra (GG), grown at smallholder plantings in the municipality of Waslala, Nicaragua, were evaluated for two successive harvest periods. Cocoa samples were fermented using a technique mimicking recommended on-farm practices. The sensory cocoa quality was assessed by experienced tasters, and seven major chemical taste compounds were quantified by near infrared spectrometry (NIRS). The association of the nine, partially admixed, genotype spectra with the analytical and sensory quality parameters was tested. The individual parameters were analyzed as a function of the factors GG and harvest (including the date of fermentation), individual trees within a single GG were used as replications. In fermented cocoa, significant GG-specific differences were observed for methylxanthines, theobromine-to-caffeine (T/C) ratio, total fat, procyanidin B5 and epicatechin, as well as the sensory attributes global score, astringency, and dry fruit aroma, but differences related to harvest were also apparent. The potential cocoa yield was also highly determined by the individual GG, although there was significant tree-to-tree variation within every single GG. Non-fermented samples showed large harvest-to-harvest variation of their chemical composition, while differences between GG were insignificant. These results suggest that selection by the genetic background, represented here by groups of partially admixed genotype spectra, would be a useful strategy toward enhancing quality and yield of cocoa in Nicaragua. Selection by the GG within the local, genetically segregating populations of seed-propagated cacao, followed by clonal propagation of best-performing individuals of the selected GG could be a viable alternative to traditional propagation of cacao by seed from open pollination. Fast and gentle air-drying of the fermented beans and their permanent dry storage were an efficient and comparatively easy precondition for high cocoa quality. © 2013 Trognitz et al.


Miranda F.,Swedish University of Agricultural Sciences | Miranda F.,National University of Agriculture at Nicaragua | Bylund H.,Swedish University of Agricultural Sciences | Gronberg L.,Swedish University of Agricultural Sciences | And 2 more authors.
Environmental Entomology | Year: 2011

The diamondback moth Plutella xylostella (L.) (Lepidoptera: Plutellidae) is a serious pest of economically important brassica crops such as cabbage (Brassica oleracea Linne). To address the current lack of baseline information concerning predators of P. xylostella, and their potential role as biological control agents, especially in Central America, we aimed to 1) identify predators in northern Nicaragua, and estimate their population densities; 2) assess their killing rate of eggs and larvae of P. xylostella; and 3) assess if predators feed more of smaller P. xylostella larvae. Individuals of selected predator groups were offered eggs, second-or third-instar larvae. Our results indicate that there exists a broad spectrum of predators, within and around cabbage fields in Nicaragua that have the capacity to feed on P. xylostella eggs and larvae under laboratory conditions. Predators with the highest killing rates were adult and larval rove beetles (Staphylinidae), sheet weaving spiders (Linyphiidae), and larger jumping spiders (Salticidae). Although all predator densities varied in space and time the consistently most abundant predator groups with the highest consumption or killing rate, and consequently the highest potential for suppressing P. xylostella populations were wolf spiders (Lycosidae) and rove beetles (Staphylinidae), although sheet weaving spiders, jumping spiders, assassin bugs (Reduviidae), and damsel bugs (Nabidae) also can be important. We conclude that those generalist predators exhibiting the highest killing rates in the laboratory should be considered for further study in the field as candidate species with a role in the management of pest P. xylostella. © 2011 Entomological Society of America.


Blandon-Diaz J.U.,National University of Agriculture at Nicaragua | Blandon-Diaz J.U.,Swedish University of Agricultural Sciences | Widmark A.-K.,Swedish University of Agricultural Sciences | Hannukkala A.,Mtt Agrifood Research Finland | And 3 more authors.
Phytopathology | Year: 2012

Late blight caused by Phytophthora infestans (Mont.) de Bary is a constraint to both potato and tomato crops in Nicaragua. The hypothesis that the Nicaraguan population of P. infestans is genotypically and phenotypically diverse and potentially subdivided based on host association was tested. A collection of isolates was analyzed using genotypic markers (microsatellites and mitochondrial DNA haplotype) and phenotypic markers (mating type, virulence, and fungicide sensitivity). The genotypic analysis revealed no polymorphism in 121 of 132 isolates of P. infestans tested. Only the Ia haplotype and the A2 mating type were detected. Most of the tested isolates were resistant to metalaxyl. The virulence testing showed variation among isolates of P. infestans. No evidence was found of population differentiation among potato and tomato isolates of P. infestans based on the genotypic and phenotypic analysis. We conclude that the Nicaraguan population of P. infestans consists of a single clonal lineage (NI-1) which belongs to the A2 mating type and the Ia mitochondrial DNA haplotype. Moreover, based on the markers used, this population of P. infestans does not resemble the population in countries from which potato seed is imported to Nicaragua or the population in neighboring countries. The data presented here indicate that the NI-1 clonal lineage is the primary pathogen on both potato and tomato, and its success on both host species is unique in a South American context.© 2012 The American Phytopathological Society.


Bommarco R.,Swedish University of Agricultural Sciences | Miranda F.,National University of Agriculture at Nicaragua | Bylund H.,Swedish University of Agricultural Sciences | Bjorkman C.,Swedish University of Agricultural Sciences
Journal of Economic Entomology | Year: 2011

Intensive use of pesticides is common and increasing despite a growing and historically well documented awareness of the costs and hazards. The benefits from pesticides of increased yields from sufficient pest control may be outweighed by developed resistance in pests and killing of beneficial natural enemies. Other negative effects are human health problems and lower prices because of consumers' desire to buy organic products. Few studies have examined these trade-offs in the field. Here, we demonstrate that Nicaraguan cabbage (Brassica spp.) farmers may suffer economically by using insecticides as they get more damage by the main pest diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), at the same time as they spend economic resources on insecticides. Replicated similarly sized cabbage fields cultivated in a standardized manner were either treated with insecticides according common practice or not treated with insecticides over two seasons. Fields treated with insecticides suffered, compared with nontreated fields, equal or, at least in some periods of the seasons, higher diamondback moth pest attacks. These fields also had increased leaf damage on the harvested cabbage heads. Weight and size of the heads were not affected. The farmers received the same price on the local market irrespective of insecticide use. Rates of parasitized diamondback moth were consistently lower in the treated fields. Negative effects of using insecticides against diamondback moth were found for the density of parasitoids and generalist predatory wasps, and tended to affect spiders negatively. The observed increased leaf damages in insecticide-treated fields may be a combined consequence of insecticide resistance in the pest, and of lower predation and parasitization rates from naturally occurring predators that are suppressed by the insecticide applications. The results indicate biological control as a viable and economic alternative pest management strategy, something that may be particularly relevant for the production of cash crops in tropical countries where insecticide use is heavy and possibly increasing. © 2011 Entomological Society of America.


Loaisiga C.H.,National University of Agriculture at Nicaragua | Loaisiga C.H.,Swedish University of Agricultural Sciences | Brantestam A.K.,Nordic Genetic Resource Center | Diaz O.,University of Los Lagos | And 2 more authors.
Genetic Resources and Crop Evolution | Year: 2011

Teosintes are the closest relatives to modern maize, Zea mays L. ssp. mays. They are wild grasses with a native distribution area from Mexico to Nicaragua and represent an important genetic resource. However, the genetic diversity of Nicaraguan teosinte (Zea nicaraguensis Iltis et Benz) has not yet been determined. This teosinte species has decreased in the last 25 years and now must be regarded as an endangered species. An analysis of the genetic diversity of Zea nicaraguensis was carried out in a total of 240 individuals from seven populations. Eleven Simple Sequences Repeat (SSR) primer pairs were used. A total of 42 alleles were found, the range of alleles per locus was 2-5 (mean 3.8) and the numbers of genotypes varied between primers. The primer Bnlg 1538 showed the highest value, with 45 genotypes through all populations. The genetic diversity observed (Ho) between all populations varied from 0.51 to 0.63, with an average of 0.563. One of the populations had as many as 40 alleles. Analysis of molecular variance (AMOVA) revealed that most of the variation was within population, at a significantly high level (P < 0.001). Rare alleles were detected in all populations, but unique alleles were only found in four populations. These results are highly relevant when developing conservation strategies and show that preserving populations in their natural habits is highly important. © 2010 Springer Science+Business Media B.V.


Mason M.,Alcorn State University | Cuadra E.J.,Alcorn State University | Elsasser T.H.,U.S. Department of Agriculture | Lopez J.,National University of Agriculture at Nicaragua | Yoonsung J.,Prairie View A&M University
Canadian Journal of Animal Science | Year: 2013

Fifty-eight non-lactating cows previously synchronized for estrus were assigned to two treatments to assess the effects of progesterone supplementation and its correlation with tumor necrosis factor-α (TNF-α) and cortisol on the survival of the transferred embryos. On day 7 after exhibiting estrus (day 0), cows in both groups received embryos. In contrast with the control group, animals in the CIDR-group had a controlled internal drug release (CIDR) additionally inserted. Blood samples for progesterone, TNF-α and cortisol analysis were taken immediately before insertion and removal of CIDRs and 7 d after insertion. Progesterone did not differ between the control and the CIDR animals at any day of the study; however, it significantly increased at 7 and 14 d after insertion of the embryos in the control animals, compared with the levels observed in that same experimental group at the time of the transfer. Regardless of the treatment, all pregnant cows experienced a significant increase in progesterone from day 0 to day 7. Progesterone on day 0 was correlated to itself (r =0.46) on day 14 and to TNF-α (r = -0.37) on day 0 in pregnant animals; TNF-α on day 7 was significantly higher in pregnant cows compared with non-pregnant and correlated between day 0 and day 14. These results suggest that high levels of progesterone during the first 14 d after the transfer are indicative of the survival of transferred embryos. Additionally, these data also indicate that the decrease in TNF-α concentration on day 7 after the transfer of embryos may be associated with the low concentrations of progesterone observed in the non-pregnant animals.

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