bluuebunny/crossref_metadata_2025 huggingface dataset:
Determinación de la edad susceptible del fruto de la papaya (Carica papaya L.) a la antracnosis (Colletotrichum gloeosporioides. (Penz.)).
Authors: Durán Alfredo , Mora Dennis , Chavarría Erick
Published: October 2018

A research was carried out in Sarapiquí, Heredia, Costa Rica, between May and September, 1993. The objective was to determine the phases of susceptibility of native papaya to anthracnose produced by Colletotrichum sp., as well as to prove the presence of anthracnose-resistant genotypes. Results indicated that at all ages, fruits examined were susceptible to anthracnose, and that a combination of native papaya genotypes may either present a permanent resistance to the disease, or never show any signs at all. There was no evidence to prove that fruits might show a temporary resistance at certain development phases, which might be camouflaged by subsequent susceptible periods. Nor was there evidence to suggest phases of greater or lesser susceptibility to the disease. Some native papaya genotypes showed resistance through the period examined.
Mejoramiento genético de frijol tipo Andino para Panamá: Resultados de un proyecto de PROFRIJOL. 1993-1996.
Authors: Rodríguez Emigdio , Lorenzo Edwin , González Francisco
Published: October 2018

Native germplasm of a Panama common bean was evaluated in order to obtain its morphologic characteristics and compare them with a group of lines and varieties of CIAT’s breeding program. The purpose was to find a germplasm that could surpass native varieties in terms of its resistance to Web Blight, yield, growing habits, and grain color. A randomized complete block design was used. Five promising lines for commercial use were selected based on yield, resistance to Web Blight, growth pattern, and grain color criteria. Three bean lines are undergoing validation trials in farms.
El Consorcio Cooperativo de Comercialización, Costa Rica: frijol.
Authors: Mora Floribeth , Abdelnour Ana , Herrera Franklin , Salazar Joaquín
Published: October 2018

The admission of Costa Rica into the World Trade Organization, and the subscription of the Bilateral Free Trade Agreement with Mexico and the agreements with other Central American countries brought about important changes in bean commercialization in Costa Rica. This partly resulted in the creation of CCCRL as an alternative for bean commercialization. Operation and viability of this Consortium are analyzed under the new conditions for the commercialization of agricultural and arming products, both at a national and international level. Agroecological crop conditions are also examined, as well as the socio-economic and cultural characteristics of the population involved in bean production, and their possible influence on CCCRL viability.
Manejo de la mustia hilachosa (Thanatephorus cucumeris (Frank)) en el cultivo del frijol comun (Phaseolus vulgaris L).
Authors: Rodríguez Emigdio , Lorenzo Edwin , Acosta Miguel , González Francisco , Mora Bernardo , Godoy Graciela
Published: October 2018

Several studies about web bligh control were carried out in Panama, the Dominican Republic, and Costa Rica. The pathogen´s genetic variability, bean varietal tolerance, chemical control, and sowing densities were evaluated. In Panama yield was increased through Benomyl applications and a greater sowing density. In the Dominican Republic Rhizoctonia AG 4, AG 2 2 and AG 1 groups were found. Several bean genotypes were evaluated, as well as populations from the web blight tolerant JB X MUS 14 cross. Between 20% and 40 % web blight severity was found in Costa Rica. Coverage and application of chemicals improved bean yield.
Evaluación de diversos patrones heteróticos en la formación de híbridos de maíz para el bajío mexicano.
Authors: De León Humberto , Ramírez Ernestor , Martínez Gaspar , Oyervides Arnoldo , De la Rosa Alfredo
Published: October 2018

This research was carried out to evaluate and characterize several heterotic patterns as a breeding strategy for developing hybrids for the Bajio region in Mexico. It was based on the performance of the crosses made, in the estimation of the type of gene action within each heterotic pattern, and the proportion of high yielding hybrids for intermediate or middle-altitude regions of Mexico. The genetic material evaluated included three heterotic groups: Tropical x Bajio (TxB); Dwarf x Normal (DxN), and Early x Late (ExL), with 20 hybrids each one and two commercial controls recommended for the region. Hybrids were developed using a nested mating design, where each of five males was crossed with four females. Hybrids were considered as full-sibs, and then, utilized for the genetic characterization of the groups or heterotic patterns. Data were recorded for ear yield at 15,5% moisture content, days to anthesis, days to silking and plant height. Hybrid evaluation was conducted in two representative locations of middle-altitude (1100 to 1900 masl) regions during the spring-summer season of 1995 at Celaya, Gto.and Sandia el Grande, N.L. Results showed that the ExL pattern produced hybrids having the best agronomic traits and the highest genetic variance. Due to the intrinsic asynchrony difficulties it was concluded that the DxL pattern was the best strategy for developing hybrids for the middlealtitude regions of Mexico.
Rhabdovirus en papayo (Carica papaya L.) en el sureste de México.
Authors: Becerra Enrique Noé , Cárdenas Elizabeth , Lozoya Héctor , Mosqueda Raúl
Published: October 2018

In commercial papaya plantations of the southeastern Mexican States of Chiapas, Tabasco, Oaxaca and Veracruz, 0.1 to 10% incidence of plants with peculiar symptoms were observed, sampled and studied for viral infections. Stem internodes were shorter than normal, the leaves were smaller and harder. There was necrosis in younger leaves, petioles were shorter and curved with reddish-gray stripes, and flower and small fruits were standing upright. In negative staining bullet-shaped particles were observed, as well as rod shaped and isometric ones. Bacilliform particles with a perinuclear membrane were also observed within the nucleus in ultra thin preparations, and stained preparations inclusions were present in the nucleus of the floem. The disease could not be mechanically nor seed transmitted. The incidence was higher in the summer than in the winter. All the description coincided with an infection by the papaya apical necrosis Rhabdovirus, although mixed with the papaya ringspot Potyvirus and with an isometric particle not identified.
Impacto de la investigación en mejoramiento de maíz en Centroamérica y el Caribe: 1966-97.
Authors: López-Pereira Miguel A.
Published: October 2018

Results of a CIMMYT study to determine the impacts of maize breeding research in Latin America in 1966-97 are presented, specifically in this case for Central America (Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama) and the Caribbean (Cuba, Haiti, Dominican Republic). This study is part of a worldwide effort by CIMMYT to update a similar study done in 1992. Results are presented here on the number and characteristics of all the maize varieties and hybrids released by public research programs since 1966; investment in maize research by public and private organizations; the volume of maize seed sold in recent years, maize seed prices; maize area planted to improved seed and the estimated value of the surplus maize production due to the use of improved seed; and legal and regulatory aspects of maize seed industries in the region. The relationship between the national maize research programs and CIMMYT is also addressed especially how these organizations have worked together over the years to advance the knowledge and the development of new improved maize technologies.
Mejoramiento genético para tolerancia a altas temperaturas y resistencia a mosaico dorado en frijol común.
Authors: Rosas Juan Carlos , Castro Aracely , Beaver James S. , Pérez Carlos A. , Morales Adrián , Lépiz Rogelio
Published: October 2018

In 1994-95, sources of heat tolerance were identified in common beans after screened several germplasm and advanced lines nurseries in Choluteca and Nacaome (≤ 50 masl), in the southern region of Honduras. The best heat tolerant genotypes were validated under greenhouse controlled conditions (35/27 °C day/night) in Geneva, New York. Afterward, crosses were made to develop small-red bean lines with heat tolerance and resistance to BGMV and other limiting factors. The F2- F5 segregant populations were evaluated for multiple traits including BGMV, common bacterial blight, angular leaf spot, rust, low fertility conditions, and selected for agronomic performance and commercial value. In 1998, 217 F6 and F7 advanced lines were evaluated in the irrigation district Lempa-Acahuapa (20 masl), in the Pacific region of El Salvador for heat tolerance and BGMV. The same nurseries were evaluated in Liberia, in the Northwest region of Costa Rica, for tolerance to high temperatures; and at Zamorano, Honduras for resistance to common bacterial blight, angular leaf spot and rust. A group of lines were identified having superior yield and adaptation than commercial checks, under high temperature conditions in El Salvador and Costa Rica. Some of these lines were also resistant to BGMV in El Salvador, and moderate resistant to web blight in Costa Rica, and they had excellent agronomic performance and good commercial value.
Genotipos de frijol (Phaseolus vulgaris L.) resistentes a Xanthomonas campestris pv. phaseoli de México.
Authors: Navarrete Rosa , Acosta Jorge A.
Published: October 2018

During 1995 the reaction of bean genotypes from different origin to Xcp was scored under greenhouse conditions at the Valle de Mexico Experimental Station of INIFAP. Three experiments were made with a)120, b)44 and c) seven bean genotypes. Plants of a and b at the V3 stage were inoculated with razor blades using a mixture of nine Xcp strains, and c individually with seven different strains of Xcp with different grade of virulence. The disease severity was scored 20 days after the inoculation comparingwith a visual scale of nine grades. Data were analyzed under a completely random design. In a the genotypes that showed resistant reaction were: A 36, A 475, G 5686, G 11867, Harowood, SEA 14, XAN 266, MCD 4012 and REN 27. In b the resistant genotypes were: Sequía Durango, Taylor and XAN 30. The disease severity of all genotypes in each experiment showed a normal distribution, with the maximum number of genotypes at the five grade of severity in the first trial and six in the second. The resistant genotypes in the last trial showed a differential reaction and genotype by strain interaction, REN 27 and SEA 14 proved to be resistant to most of the strains inoculated. These results indicate that the inoculation of mixtures of Xcp strains with different pathogenicity was efficient to identify resistant bean genotypes.
Control de malezas en arroz de temporal con clomazone, solo y en mezcla con propanil y 2,4-D.
Authors: Esqueda Valentín A.
Published: October 2018

Three experiments were carried out in order to evaluate the effect of the herbicide clomazone, alone and mixed with propanil and 2,4-D on weed control and toxicity to rice cv. Milagro Filipino, growing under upland conditions. All the experiments were established in Los Naranjos, a rice-growing area located in the Municipality of Tres Valles, in the state of Veracruz. The dominant weed species in the experimental plots were Cyperus iria, Echinochloa colona, Cyperus rotundus, Scleria setuloso-ciliata and Malachra fasciata. Clomazone applied preemergent, efficiently controlled E. colona at 0,72 and 0,96 kg a. i./ha, but its effect was partial and temporary on S. setuloso-ciliata and it had no effect on C. iria and C. rotundus. Mixture of clomazone + propanil + 2,4-D efficiently controlled E. colona and C. iria from 0.60 + 1.44 + 0.24 kg a. i./ha. It also had a good initial control of C. rotundus, but its effect was completely lost between 45 and 60 days after the application and its effect on S. setuloso-ciliata was influenced by the soil moisture: the higher the moisture the better this weed was controlled and viceversa. Rice grain yields obtained in plots where clomazone, alone or mixed with propanil and 2,4-D was applied were statistically similar to those obtained in plots where the weed control regional treatment was applied.
Aptitud combinatoria general y específica de líneas tropicales de maíz usando probadores.
Authors: Sierra Mauro , Marquez Fidel , Valdivia Roberto , Cano Octavio , Rodríguez Flavio A.
Published: October 2018

Thus, during autumn - winter season in 1996/97, there were evaluated in Cotaxtla, Ver. top crosses of tropical maize lines derived of several sources of germplasm such as: a) Recycled lines from H-513XVS-536, b) lines derived from a compound of wide genetic base (CABG3), c) Elite lines from Cotaxtla maize program and d) CIMMYT lines . There were used as testers, the lines LT154, and LT155 which are parents of H-513 and CML247 and CML254 which cross is an heterotic pattern defined by CIMMYT for the tropic . There were found lines like F31 x F30-4-3, F41 x F40-1-2, CABG3’-12-2-1-2-1, LT-174 y CML55 that registered good specific combining ability with tester 2 (LT-155) ;and F4 x F3-5-2 and CML15,with tester 4 (CML 254). On the other hand F4 x F5-5-1, CABG3’-12-2-1- 2-1, LT-174, CML13 and CML 15 had the best general combining ability. In relation with testers, it was found for recycled lines, that testers LT154 and CML254 registered the highest values for regression coefficients; It indicates that these testers identify the best lines; In lines derived from CABG3, tester LT155 registered the best value; In Elite lines, testers 2(LT155) and 3(CML247) identified better lines and from CIMMYT lines the best tester was CML254.
Heterosis, habilidad combinatoria y diversidad genética en híbridos comerciales de maíz (Zea mays L).
Authors: De la Rosa Alfredo , De León Humberto , Martínez Gaspar , Rincón Froylan
Published: October 2018

Knowledge about the combining ability, genetic diversity and heterosis of germoplasm from a maize breeding program is essential for hybrids and varieties development. The objetives of this study were (1) To identify commercial hybrids with high genetic value (GCA and heterosis) useful for initiating a maize breeding program to produce and improved hybrids, varieties and synthetics; (2) To demonstrate that is feasible to create a maize breeding program from commercial hybrids. Estimates of general (GCA) and specific combining ability (SCA) were obtained using the method IV of Griffing (1956) and the genetic distances were estimated according to the method suggested by Troyer (1988). The best crosses were AS910 X AS4450 and PP9538 X AS948 having a yield of 17.538 and 17.463 t/ha respectively; the same crosses had the highest values of SCA. The crosses with the highest values of heterosis over the midparent were PP9539 X AN453 and PP9603 X PP9539 with 11,35 and 11,13 percent respectively. The highest positive values of GCA effects were obtained from hybrids PP9539 and AN447 with 1.168 and 0.684 t/ha respectively;. and the hybrids with the best heterosis were PP9539 ( 2.269 ) and A7500 ( 1.170 ). The most related hybrids were AS910 and AN450 with a genetic distance of 0,033 and heterosis of -47,68 percent whereas the most diverse were AN454 and A7500 with a genetic distance of 1.418 and heterosis of 12,26 %.
Fraccionamiento de nitrógeno en frijol (Phaseolus vulgaris L.) en el valle de San Juan.
Authors: Cedano Juan , De la Rosa Danna , Sánchez Alfonsina , Oviedo Fernando
Published: October 2018

An experiment was conducted in five locations in the San Juan valley, Dominican Republic, to study the response of splitting nitrogen fertilization and time of application on the seed yield of common bean (Phaseolus vulgaris L.). Trials were established between november 5 to 14,1997. In each location nine treatments were tested under a Complete Random Design. There was no response to nitrogen fertilization in a single or splitted application in locations with high nitrogen content in the soil; whereas in location with soils deficient in this nutrient, a significant response (P<0.05) was observed in both, fertilization rate and in the splitting of the doses. There were significant differences among locations (P<0.05) and the interaction location X fertilization treatment was not significative.
Sistema radical en genotipos de papa, bajo condiciones de invernadero.
Authors: Cortez S. , Camacho S. A. , Martínez Gaspar , Kuruvadi S. , Mendoza Mariano
Published: October 2018

The objectives of this research were to study variability of growing and distribution of the root system in 10 commercial and experimental potato clones and to identify the best materials in different soil profiles. It was used a complete random block design, under greenhouse conditions at the Universidad Autónoma Agraria Antonio Narro, Saltillo, Mexico. Black polyethylene containers of 90 cm long and 30 cm diameter were used for evaluating root system. Restricted irrigation was applied to increase root growing. Experimental plot was one container with two plants. After flowering and 125 days of growing, shoot was cut. Soil in every container was divided in four sections. Shoot and roots were dried at 70 °C for 48 hours and weighted. Analysis of variance revealed highly significant differences for dry root weight among potato varieties at the four considered profiles: 0-20, 20-40, 40- 60, 60-80 cm, and for total profile (0-80 cm). Boer, Russet Burbanck and Utatlan were outstanding varieties for the total production of roots. Boer Russet Burbanck, Atlantic and Gigant varieties produced the higher amount of roots in the 60- 80 cm profile and produced a good roots growing patterns in different profiles.
Identificación de malezas trepadoras del banano (Musa sp.) en la zona caribe de Costa Rica.
Authors: Rodríguez Ana María , Agüero Renán
Published: October 2018

Population of climbing weeds in banana plantations of Costa Rica have increased over the years. Taxonomic identification of these species is needed as a basis for other studies. This study is an attempt in such direction, one that should be fine tuned in the future, since identification for many of the climbing species is rather difficult. Surveys were conducted at several farms of the Atlantic region of Costa Rica. Cucurbitaceae, Araceae and Fabaceae were the families with the greater number of species.
Evaluación de variedades de cebolla en la República Dominicana.
Authors: Morales José Pablo , Navarro Félix , Rondón Félix , Báez Clemente , Genao Ricardo
Published: October 2018

A field study was conducted in order to evaluate 16 onion crops for their yield, grade and susceptibility to pests and diseases under field conditions in San Cristóbal, Dominican Republic. The cultivars 'Texas Grano 438', 'Liberty', 'Lexus', 'Domingo', 'Serrana', 'Mercedes', 'Yellow Granex', 'Cougar', XPH 6700, 'Sebaqueña', 'Contessa', 'White Hawk', 'Diamante', 'Red Creole', 'Híbrido Rojo' and 'Sivan' were distributed in randomized complete blocks with three repetitions. Experimental units consisted of two double rowsthree meters in  length. 'Red Creole', 'Yellow Granex' and 'Contessa' were utilized as prototypes for the red, yellow, and white onion crops, respectively. Onion crops were managed following a medium level technology package recommended for the zone. The variables evaluated were early development, diameter of thebulb neck at harvest, number of rings per bulb, incidence of pests and diseases, yield grades, total commercial yield, percentage of twin bulbs and percentage of rotten bulbs after curing. Statistical analysis revealed that among yellow cultivars, the materials with the best attributes of yield and bulb quality were 'Texas Grano 438', 'Lexus', 'Liberty' and XPH 6700. The yield of the of 'Texas Grano 438'. Among white onion crops, 'Diamante' and 'Contessa' were significantly better than 'Sebaqueña' and 'White Hawk' in terms of early development and/or yield. For the red crops, 'Red Creole' was significantly inferior than 'Híbrido Rojo' and 'Sivan' in bulb grade and yield.
Evaluación de coberturas orgánicas y plásticas para el control de malezas en tomate (Lycopersicon esculentum Miller).
Authors: Taravera Mario E. , Padilla José R.
Published: October 2018

Three organic mulches were evaluated: pine sawdust, sugar cane dry-bagasse, rice chaff, along with two plastic coverings: Black plastic, gray plastic and a relative control. Trifluralin was applied in pre-sowing. Hilling was applied 15 days-after treatment and weeds were controlled manually 50 days-after treatment. Seedings from Peto 98 were obtained from a greenhouse. A completely randomized block design with four repetitions was used. The higher incidence of weeds was found when using organic mulches this affected the yields of fruits. The higher return was obtained with the plastic coverings.
Producción artesanal de semilla de frijol en Veracruz, México.
Authors: López Ernesto , Ugalde Francisco J. , Contreras Rafael , Barradas Antonio
Published: October 2018

To solve the shortage of improved bean seed in the Municipalities of Medellin and Jamapa, a project for farmer’s bean seed production (PASF) was started in 1998/99, following a partnership model wich included the Municipality Office for Agriculture Promotion, bean producers and researchers from the INIFAP Bean Program. During the first growing cycle, demonstrative plots with different bean varieties and lines were established and bean growers were trained using the method of learning by doing. During the second growing cycle, bean varieties were multiplied in plots of farmers who received advice from the INIFAP researches and the PASF bean seed was delivered. With the production of four tons of bean seed and the support of the Municipality which paid for 50% of the seed cost, 100 ha were sowed by 118 bean growers during the 1999-2000 Fall-Winter growing cycle; moreover 800 kg of bean seed were directly distributed by the bean growers. Due to the irregular rainfall, grain yields of the commercial plots were variable. In the Municipality of Veracruz, the PASF varieties had a yield average of 550 kg/ha and in the Municipality of Jamapa the yield average was 650 kg/ha. Even so, these grain yields were higher than those obtained in plots sowed with seed from emergent programs or traditional farmer seed. The promoted strategy is a variable alternative to satisfy the demand of municipal bean seed and to start an adoption process of bean varieties among bean growers. This model is being promoted in other Municipalities of the State of Veracruz.
Efecto de tipos de labranza sobre la población de malezas en caña de azúcar (Saccharum officinarum L.).
Authors: León Ramón , Agüero Renán
Published: October 2018

Experiments were conducted in two sugarcane fields, one with low weed pressure (plot 1) and the other with high weed pressure (plot 2). Four treatments were established in each study: green harvest that left plant mulch on soil surface (VCR), green harvest without plant mulch on soil surface (VSR), burning the crop before harvest without soil disturbance (QSL) and burning the crop before harvest with soil disturbance (QCL). Evaluations were made 75 days after harvest. The evaluations were conducted separately in rows and between rows. In addition, sugarcane population and height were measured. Differences in weed populations were not observed for the field with low weed pressure (plot 1). In the field with high weed pressure (plot 2), weeds were favored by burning and soil disturbance caused by fertilizer incorporation. Thus the treatments QSL and QCL showed the highest percentage of surface coverage. Also, the QCL treatment had the greatest weed populations resulting in reduced sugarcane population and height. Purple nutsedge (Cyperus rotundus L.) and itchgrass (Rottboellia cochinchinensis (Lour.) Clayton) had the greatest percentage surface coverage, especially in QCL. Weed populations were larger in rows than between rows. Apparently in rows, weeds found better conditions for germination and nutrient uptake.
Degradabilidad in situ de la materia seca, proteína y fibra del forraje de morera (Morus alba).
Authors: Boschini Carlos
Published: October 2018

The purpose of this study was to determine the ruminal degradability of dry matter, crude protein, neutral detergent fiber and their fractions, contained in regrowth of mulberry at 56, 84 and 112 days. The degradation of leaves, stems and the whole plant was calculated. The potential degradability of these three components diminished as the regrowth aged. The soluble fraction of the dry matter was reduced from 29% to 25% in the leaves and from 27% to 19% in the stems between the 56th and the112th day. The degradable fraction in the stem remained constant (61-63%) on the three measuring days, with ruminal degradation levels of 14%, 10% and 9%/h respectively. In the stem the degradable fraction diminished from 42% to 30% between the 56th and 112th day, with degradation speeds of 8.4%, 6.7 % and 5.3%/h. The soluble crude protein diminished with age from 41% to 33% in the entire plant and the degradable fraction remained constant between 49% and 51%. The degradation rate was higher than 9.4%/h. The neutral detergent fiber had a degradable fraction of 71%, 62% y 43% on the 56th, 84th and 112th day, with degradation rates of 13%, 10% y 9%/h respectively. The degradation of the neutral detergent fiber began in the rumen with a lag time of 1.5 to 3.2 hours.
Situación de la producción de frijol y maíz en Concepción de Pilas y Veracruz de Pejibaye, Costa Rica.
Authors: Álvarez Pablo , Cárdenas Hernando
Published: October 2018

The socioeconomic study was conducted at the southern zone of Costa Rica, in the district of Pejibaye, located in Perez Zeledón, through an inquiry of 80 producers aleatorily chosen. The information was obtained on May, 1999. About 84% are landowners, with productive units of an average of 14.5 ha. Most of the basic grains producers diversify with others farming activities, such as spoonflower, coffee and pasture. It was determined that the level of diversification increases with the size of the productive units. Also, within the subsystem of basic grains, most of them diversify it in combination with corn and bean. Ninety percent of the producers plant corn during summer time (December to February), with an average area of 2.5 ha and with an average production of 1.9 t/ha. Regarding bean, the main crop comes on wintertime (May to August) with an average area of 3 ha, and a yield of de 0.6 t/ha. For both grains, the tendency goes to the reduction of areas and product. For corn, as well as for the bean, most of the crop goes for market, and in general, that is to say that the production of both grains have an income-producing result in terms of cost/benefit, being more profitable the bean activity. During the latter years, the climatic instabilities have affected the output of basic grains, which has made the producers to turn into other productive activities. The producers have began to use some strategies in order to encounter these effects, such as the use of coverings, and some other cultural and agronomic practices.
Combate del rocío azucarado (Sphacelia sorghi McRae) del sorgo (Sorghum bicolor (L.) Moench) con funguicidas.
Authors: Mena Héctor , Fuenmayor Francia , Tejera José , Jiménez Rafael , Georges Eudis
Published: October 2018

The experiment was conducted in Centro Nacional de Investigaciones in Maracay, Aragua, Venezuela. The goal of this job was determining the efficacy of some fungicides in controlling sorghum honeydew (Sphacelia sorghi McRae). A completely block randomized with four replications was used. Three systemic triazol fungicides were used and two non triazoles were included. Each dose was subdivided in three applications: 1/4 applied at panicle pre-emergence, 1/2 applied at 50 % flowering time and 1/4 applied at postflowering time, in order to cover the whole flowering period. The variables were: incidence or infected panicles per plot, panicle infection and the total infection/ plot. According to the results there was an overall good fungicide control. There was a group constituted by Tilt and Propizole, which gave the best fungus control with 96.96 and 96.55% of effectivity in controlling of panicles’ infection and a second group was integrated by Anvil, Benlate and Plantvax which made adequate control with no significant differences among them. In conclusion, the best fungicides were Tilt and Propizole. Benlate and Plantvax gave an adequate control but they are recommended under low inoculum pressure in order to avoid resistence and for economic reasons. Anvil showed 90.43% control; however, this fungicide has low relative efficacy when it is compared with other triazol fungicides.
Adaptación y calidad tecnológica de la variedad de frijol Negro Tacana.
Authors: López Ernesto , Becerra Noé , Cano Octavio , Zaleta Dora , Acosta Jorge
Published: October 2018

In this paper the results obtained with a uniform yield trial including 22 bean genotypes grown in three states of Mexico are presented. Under experimental conditions, bred line DOR 390 resulted outstanding for its wide adaptation, high and stable yield (1041 kg/ha, bi=1.0 Sd2i=0) Under farmer’s conditions, DOR 390 (1214 kg/ha) was superior to commercial cvs, Negro Cotaxtla 91 (1142 kg/ha) and Jamapa (867 kg/ha); at neight locations of the humid tropics in the States of Tamaulipas, Veracruz and Chiapas, DOR 390 proved to be highly resistant in comparison to Negro Huasteco 81. Comparing Dor 390 to bred cvs. and landraces of the same commercial class, tropical black, Dor 390 showed and average protein content of 25%, on a dry weight basis, and the highest fiber content of the seven genotypes evaluated. DOR 390 was registered as a new cultivar in 1993, and made available to the farmers of the humid tropics in 1994, under the name of “Negro Tacana”.
Selección para calidad fisiológica de la semilla y rendimiento en líneas S2 derivadas de cuatro poblaciones tropicales de maíz (Zea mays L.)
Authors: Navarro Enrique , Vega Cristina , Narváez Fernando , Córdova Hugo
Published: October 2018

This study was carried out in 1993 to evaluate S2 lines from four maize tropical populations improved by reciprocal recurrent selection. These lines were evaluated under field and laboratory conditions, the latter one to determine physiology quality. The main goal was to measure genetic variability within and among populations for traits such as grain yield, vigor and germination and to select the best lines under field and laboratory conditions. The combined analysis of variance showed great genetic variability among the S2 lines within and among populations for grain yield, days to flower, plant and ear height, among others. The maximum genetic variability was observed on the lines from population 43 and pool 23 for most of the traits, although the latter showed a greater genetic variability for grain yield. Besides, it is important to mention that the above populations included the best genotypes for grain yield, germination and vigor. Taking into account the above mentionel agronomic traits, fifteen lines were selected; 2 belong to population 43* pool 20, 2 from pool 19* pool 23, 8 from population 43, and 3 from pool 23. These results confirm the genetic superiority of the lines from populations 43 and pool 23, so that these populations should be recommended for future genetic improvement by reciprocal recurrent procedures.
Control preemergente y postemergente de malezas en frijol, de humedad residual en Veracruz, México.
Authors: Cano Octavio , López Ernesto
Published: October 2018

In the period from the Fall of 1993 to the Winter of 1994, at the Cotaxtla Experimental Field, a research with the goal of determining the most efficient pre-emergent and post-emergent herbicides was performed, in order to control weeds in bean plantations in the optimal and most economic way. The dominant weeds at the experimental site were: Yellow Flower (Aldama dentata) and “pitillo” grass (Ixoporus unisetus). The pre-emergent herbicides: Metribuzina, 0.350 Kg i.a./Ha, Alaclor + Metribuzina 1.5 + 0.210 and 1.5 + 0.290 Kg i.a./Ha, were found to control grass and broad leaves in an acceptable way. The optimal treatment was that of Alaclor + Metribuzina 1.5 + 0.210 kg i.a./ha with a TMR of 1655% and an RBC of 10.6. The best post-emergent herbicide to control broad-leaf weeds and grass, was the mixture of Fluazifop Butil + Fomesafen 0.125 + 0.25 kg i.a./ha, as the most economic and optimal post-emergent with a TMR of 36% and an RBC of 6.3. We obtained the best yields with 1061 kg/ha. Imazethapyri Chlorimuron Ethyl were found to be highly toxic for the bean plant (100%).
Preliminar de rendimiento de líneas uniformes de arroz.
Authors: Castañeda Wilfredo , Guerrero Luis
Published: October 2018

With the objective of selecting and make available for the Basic Grains Program the promisory germ-plasm of rice, with high potentials for yields, resistant or tolerant to fungi-caused diseases, particularly piricularia (leaf blast), good plant architecture and adapted to different eco-systems in El Salvador. The study was implemented in two different surroundings: the Center for Technological Development in Izalco and the Center for Technological Development in San Andres, using the dry method. We evaluated 91 materials in simple lattice of 10 by 10, with two replicates. Two lots were sowed using six furrows with a lenghth of five meters each, separated by 0.30 meters. We used as indicator the commercial varieties X-10, CENTA A-4, CENTA A-5 and the elite lines L-1951, and L- 1956. The results we obtained were subjected to analysis for variation and selection index, identifying the best 15 materials by their yield, their vegetative cycle, and their reaction to diseases. The outstanding lines were elite L-1956 (5.7 t/Ha), used as indicator, and other lines: CT-8889-10-16-2-1-M, C-109 Cu83-SmCu-11Cu-5CU-1CU-MS, C145Cu82- SmCu-SmNa7Cu-4Cu, 3Cu-2Cu-MS, with yields of 5.6, 5.5. and 5.4. (t/Ha) respectively; all this surpassing the commercial indicator with largest production, CENTA A-5, which yielded 5.2 t/Ha. We recommend the evaluation of selected materials, in yielding assays.
Producción de frijol en Cuba: situación actual y perspectiva inmediata.
Authors: Chailloux Marisa , Hernández Germán , Faure Benito , Caballero Roberto
Published: October 2018

In Cuba aproximately 38.000 ha of beans are sown in the Ministry of Agriculture, with a total production old to the state of 9.000 t. The highest porcentage belongs to state agencies under favorable environment and monoculture rotational system. The reminder is produced in agronomy cooperatives and by individual farmers; in all the cases yields are low. Experimental results obtained in the country, indicate that higher yields could be obtained. The main limiting factors affecting bean produce are: the lack of the areas devoted to this crop, low level of technology adoption and transference, poor availability of quality seed for the whole planted area and unefficient management of the harvest and post harvest. The conclusion is that there are agroecological and structural conditions, as wellas a great deal of research results, which allow to resort to the popularization of the crops, together with a sustainable territorial self-production of the grain for consumption and seed. To develope a broad base extension service program that allows the knowledge up-to-date of the producers and to keep the development of the national research programin permit to meet the availability for new technologies to  face the diversity of problems involved in bean production.
Control químico de malezas en frijol (Phaseolus vulgaris L.) en el estado de Veracruz.
Authors: Esqueda Valentín A. , Cano Octavio , López Ernesto
Published: October 2018

Two experiments wiht herbicides were carried out during the Fall-Winter seasons of 1990-91 and 1991-92. The objective was to determine the best preemergence and/or postemergence herbicide treatments for controlling the dominant weed species in the residual moisture growing sistem of beans. The experiments were established in the central area of the state of Veracruz, Mexico.In both experiments, treatments were distributed in a CRBD with 12 treatments and four replications. Melampodium divaricatum and Cyperus rotundus were the dominant weed species in both experimental sites. Euphorbia heterophylla and Sorghum halepense were dominant in one location each. In preemergence, the maximum control of M. divaricatum was obtained with alachlor (2 kg a.i./ha) and linuron (2 kg/ha), the last herbicide was also efficient to control E. heterophylla. In postemergence, fomesafen (0.25 kg/ha) showed an efficient control of the two dominant weed species. No treatment controlled C. rotundus, and S. halepense was only controlled with a treatment included fluazifop-butyl. Linuron and alachlor caused toxicity to the bean plants when the residual moisture of the soil was high. However, and contrary to the response observed with these two herbicides, fomesafen caused a higher toxicity when the residual moisture in the soil was low.
Efecto de la gallinaza en plantaciones de cacao (Theobroma cacao L.) en desarrollo.
Authors: Orozco María , Thienhaus Susanne
Published: October 2018

We studied the effect of the organic chicken manure on the growth and development of cocoa trees (Theobroma cacao L.), during their juvenile stage. The experiment was initiated in February, 1993, in three commercial plantations, 20 months old, located in the county of El Rama, Region V. During the following 14 months we carried out three application , comparing, the three levels of chicken manure (454 , 908 . and 1,362 g per tree and application) with mineral fertilizer (three applications , of 15-15-15fertilizers100 g per tree, plus one application of, urea 100 g per tree), and a check without any applications. A random complete bolck design was utilized and means were compared by, Duncan’s test and regression and correlation analyses were also made. The results showed that with the application of 1,362 g of chicken manure, a significatively higher effect over the initial production of cocoa, and an increase of the stalk diameter were observed. The applications of 454 and 908, of chicken manure resulted in production levels equal to those of the treatment with mineral fertilizers. In relation to plant height, we did not find statistical differences among treatments. The treatment without fertilizer , showed the smallest growth and lower production.
Influencia de la fecha de siembra y la poda sobre la producción de cultivares de ocra (Abelmoschus esculentus).
Authors: Díaz-Franco Arturo , Ortegón Alfredo S.
Published: October 2018

The production of five okra cultivars (Abelmoschus esculentus) during the regular planting season and after pruning was evaluated. Four hybrids and the variety ‘Clemson Spineless 80’ were tested in two planting dates during 1994 (Feb-15/Mar-22) and 1995 (Feb-21/Mar-15).At the end of the regular season, the stalks of the plants were cut 25 cm above the soil surface to measure the fruit after pruning. During the regular season, march planting dates showed precocity. Most of hybrids showed harvest precocity and larger fruit yields than ‘Clemson Spineless 80’ , ‘Cajun Delight’ registered the highest yield in both years. After pruning in 1994, hybrids were four days earlier precocious than the variety, and ‘Green Best’ and ‘North- South’ had the greatest yields in the two plantings dates. Additionals yields ranging from 10% to 76% were obtained by pruning .The planting date of Feb-15 was superior in the total yield. Pruning production in 1995 was affected by a high incidence of sweetpotato whitefly (Bemisia argentifolii) populations.
Efecto de coyolillo (Cyperus rotundus) sobre el crecimiento de canavalia (Canavalia ensiformis).
Authors: Lara Francisco , Serrano Leopoldo , Aguirre Carlos , Villatoro Raúl
Published: October 2018

During the summer 1995, at the Experimental and Training Station of the Agronomy School of the University of El Salvador, an experiment was established by alternating sword bean (0.80 m. x 0.50 m) with maize (0.80 m. x 0.30 m.), under zero management. The plot was divided in two areas one with a high infestation of “coyolillo” and other with a predominance of wide-leaf weeds, such as Baltimora recta, Melantera sp., Lantana camara, and Panicum sp. Samples were taken in each area every 10 days, by using 10 sword plants to determine the following variables: plant height, dry weight, absolute growth rate, and relative average growth rate. The infestation with Cyperus initially oscillated between 1200 to 1650 young sprouts/m2. The experiment was analyzed under the concept of paired plots. The results indicated significant differences for the height of Canavalia plants, increasing from 10 dds to 20 and 30 dds, reaching the maximum growth in the plot without Cyperus, reaching 108 cm at 40 dds, in contrast with plants with competence by Cyperus, which attained a maximum height of 82.9 cm. This showed an unfavorable competition to Canavalia, which was also supported by the accumulation of dry matter.
La rentabilidad social de la investigación agrícola gubernamental en granos básicos: el caso del maíz en Guatemala, 1973-90.
Authors: Reyes Mamerto
Published: October 2018

In this paper we evaluate the social rentability of maize agricultural research conducted at the Institute of Agricultural Science and Technology (ICTA), from 1973-90. We used an econometric model ofthe national maize market in Guatemala. As social benefits we take into account the increases in the surpluses ofproducers and the savings obtained by notimporting maize. In the evaluation we obtained a B/C relationship of 6.06 and a TIR of 96.95%, which indicate that maize agronomic research has proved to be a highly profitable activity for this society.
Algunas pautas de manejo de las malezas para incrementar los insectos benéficos en el cultivo de palma aceitera (Elaeis guineensis Jacquin).
Authors: Mexzón Ramón
Published: October 2018

We found that weeds most frequentIy visited by insects were, in descending order, the species of Asteraceae, Euphorbiaceae, Leguminose and Malvaceae. Of those, 23 were annuals and 38 were perennials. The annual plants flowered during the dry season and the perennial during various periods along the year. Most ofthose species grew in fields with young oil palm trees without the "Kudzu" cover, as well as on roadsides, along canal s and drainage and on clearings inside adult plantations. Some perennial plants with extra-floral glands, growing in fields with adult oil palm trees, proved to be very attractive to insects. The increase in the arthropod population (including beneficial insects), can be obtained through a conservative management of the vegetation. We point out the need to support such changes in the vegetation, based on ecological studies, in order to avoid favoring damaging insects and or pathogenic agents, and also in order to evaluate the effect of such measures over health and yield of the crop.
Combate de malezas, en monocultivo de maní forrajero (Arachis pintoi).
Authors: Araya Eugenio , Elizondo Jorge , Jiménez Carlos , Quan Anaité
Published: October 2018

We evaluated four chemical treatments (herbicides) used to fight weeds, as compared to manual weed picking and using a witness treatment. All treatments had a rotational handling with 6.5 animal units (12 animals of 250 kg per five haurs). We used a proteid bank or monoculture of forage peanut, in an arca of 1080 sq.mt., with a 30 days break. In order to evaluate the many variables, we used an experimen-tal design of complete random blocks, with six treatments and tree repetitions per treatment. In order to determine the coverage of the culture, its tolerance to the active ingredient and the level of treatment control, we carried out four evaluations: 0, 30, 60, and 90 days of treatment application. We found differences (P<0.01) between treatments related to the degree of coverage of the forage peanut plants. With Gliphosate and manual weeding, we obtained a dominant coverage of forage peanut, while with the witness treatment the degree of coverage was inferior. The production of dry matter from the weeds, as well as their percentage in the pasture, decreased in a significant way (P<0.01), through the sampling process. With the witness treatment we obtained the largest amount of dry matter in the weeds, and also the highest percentage of weeds in the pasture.
Combate de fitopatógenos en almácigo de cebolla (Allium cepa L.).
Authors: Navarro Juan Ramón , Umaña Gerardina
Published: October 2018

The effect of several treatments to control root pathogens on onion seedlings (Allium cepa L.) were studied. The test was carried out in Bagaces, Guanacaste province, Costa Rica. Treat-ments tested were: Benomil + Captan, solarization for three weeks ,solarization for four weeks , compost at arate of 25 t/ha, and a control. During the test weather conditions were exceptionally wet thus increasing the pathogen pressure beyond normal. Despite weather conditions, the compost treatment showed the highest plant survival and seedlings. The use of compost seems to be an adequate altemative for the production of onion seedlings.
La asociación maíz-frijol como alternativa para agricultura con problemas de heladas.
Authors: Barrales José S.
Published: October 2018

During 1994, in Cuapiaxtla Valley, in Taxcala, Mexico, a region with frequent freezing injury to crops, the association of maize and common beans was evaluated to find out the potential of the maize plant cover in reducing damage on bean plants by freezing temperatures. A chilling wave 126 days after planting caused the death of maize plants, while the bean plants completed their biological cycle and produced 350 kg/ha.
Validación de la línea de frijol común (Phaseolus vulgaris) DOR 482, en la zona oriental de El Salvador
Authors: Ventura Rolando , Reyes Carlos
Published: October 2018

This study was conducted during 1995 in the eastern region of El Salvador, formed by the departmcnts of Usulutan, San Miguel, Morazan and La Union, all of them traditionally bean cultivation areas, in particular during the second cropping period (august-september). Thirty six plots of 1000 m2 each were established to evaluate at the farm level the line of the common bean DOR 482. The statistical design was that of paired plots where the check was the local variety and the new technology was the DOR 482. Plots were managed based on each farmer's different technology. Agronomical, culinary and yield characteristics were measured. During the croppingcycle ten field trips were perfomed with a total of 196 farmers. Growing habit and yield were the agronomiccharacteristics of DOR 482 preferred by most farmers. Regarding culinary aspects, 57% chosed DOR 482 as softer, 64% as bettertasting, and88% as the one producing the thickest soup. As for yielding characteristics the average yield for the local varieties was 681,31 kg/ha (10,5 qq/mz) and the averagefor DOR 482 was 1034 kr/ha (15,93 qq/mz), a 51,8% increase over the local varieties.