Ammonia emissions from dairy and livestock operations are of significant environmental and human health concern in the United States. Conservation of ammonia from fall surface-applied manure could benefit farmers by retaining nitrogen for use by crops in the spring growing season. The primary goal of this research was to investigate a management strategy for mitigating ammonia volatility from cow manure at the time of field application with no incorporation in the fall before snow fall. The hypothesis is that application of manure in cooler fall temperatures will slow the rate of ammonia volatilization. The objective was achieved by measuring temperature and rates of ammonia volatility from surface-applied liquid dairy manure every month over a period of four months from September to December, 2008. Manure was surface-applied to a field cover-cropped with winter rye (Secale cerealeL.) in September. Ammonia emissions were measured using a dynamic chamber method. Colder temperatures significantly reduced rates of volatility and amounts of nitrate found in the soil. However, N-accumulation in the cover crop fluctuated and was not significantly different from month to month. The greatest spring nitrogen retention and lowest rates of ammonia volatility in the fall were from December plots. Surface application of liquid dairy manure should be conducted as late as possible in the fall before snow fall for the least amount of nitrogen loss due to ammonia volatilization. Planting a cover crop at the time of fall harvest in conjunction with a late fall (November or December) manure application is a nutrient management strategy which deserves further investigation.

Soybean growers in the southern United States commonly deal with disease issues that can limit yield potential. As a result, growers have adopted prophylactic fungicide application targeted at specific growth stages as a standard management practice. However, yield responses to prophylactic applications have become sporadic over time. One major change that has occurred is adoption of cultivars with improved disease tolerances. Therefore, the objective of this research was to evaluate yield response of cultivars representing multiple genetic backgrounds to fungicides applied prophylactically at the R4 soybean growth stage. Experiments were conducted in 2020 and 2021 to determine the yield impact of prophylactic fungicide applications in MG IV or V cultivars across different planting dates and multiple soil textures. A yield increase was observed for soybean treated with a fungicide compared to nontreated soybean. However, a yield response between nontreated and treated soybean within cultivar was not observed, indicating that differing cultivar disease tolerances may not influence soybean yield response to prophylactic fungicide application.

This study was conducted in two locations: Pucará (2,413m above sea level) and Mojandita (2,922m above sea level), both of which are found in the province of Imbabura, Ecuador. The objectives of this study were to: characterize the morphological and agronomic traits as well as the overall quality of the ten amaranth accessions in this study; identify the accessions with the highest yield and biomass; determine the nutritional characteristics of the experimental accessions; and determine the cost of production of amaranth per hectare. The following null hypothesis was assumed: the agronomic and nutritional characteristics of the ten accessions in this study are equal in both locations. A randomized block design with ten treatments and three repetitions was employed for each location. The following tests of significance were performed: Tukey test at the 5% significance level for accessions, DMS at 5% for locations and Combined Analysis for the variety x location interaction. The following lines were used: ECU-0014, ECU-0113, ECU-2210, ECU-4737, ECU-4744, which represented pale-seeded grain types, and ECU-0069, ECU-0082, ECU-0102, ECU-0123 and ECU-0162 represented dark-seeded grain types. These accessions were analyzed for: plant height, diameter of the base of the stem, stem length, panicle length, grain/plot yield. Based on the results of this study, we conclude that no significant difference exists between the accessions on the basis of plant height and stem length in either location. For stem diameter, panicle length, and yield, however, significant differences among the accessions were detected. Between locations, the most promising results were observed in Pucará. The accession ECU-2210 gave the highest yield in Mojanda, with 1,300 kg/ha, while the accession ECU-0014 had the highest yield in Pucará, with 1,400 kg/ha. Overall, the best protein and iron content was observed in Mojanda; the accessions ECU-0162 and ECU-4744 had the highest percentage of protein, with 14.93% and 14.58% respectively. The highest observed iron content was 465.0 ppm in the accession ECU-0102. The cost of producing one hectare of cultivated amaranth grain is $1,543.95. The sale of this investment totaled $2,520, giving a cost-benefit ration of $0.63. Growing the accessions ECU-0612 and ECU-4744 is recommended if high protein content is desired, while the accession ECU-0102 is recommended in order to obtain the highest iron content. To obtain the highest yield per square meter, the accessions ECU-2210 is recommended at altitudes of 2,900m above sea level, while ECU-0014 is recommended for altitudes less than 2,600m. Based on the results of this study, it is not recommended that amaranth be planted at altitudes higher than 3,000m.

This study was done with the objective of evaluating the agronomic performance of five varieties of forage grasses introduced to the community of Carmen Pampa in the province of Nor Yungas, La Paz from 2005-2006. The average temperature during the study was 11.93ºC and the average precipitation was 801.75 mm. The trial was done with a design of randomized blocks having five species and six repetitions. The species studied were: Panicum virgatum, Sorghastrum nutans, Andropogon gerardii, Tripsacum dactyloides, and Eragrostis curvula. Variables evaluated were: plant height (cm), coverage (%), number of plants, bunches of florets, and dry matter yield (kg/ha). The forage species that grew highest were Eragrostis curvula (55.5 cm) and Panicum virgatum (44.96 cm). Those same species also showed the best performance in regard to coverage with 88% and 33.4%, respectively. Eragrostis curvula had the largest number of plants with an average of 72.5 plants per m2. With regard to bunches of florets, Eragrostis curvula had the most with 31.33 bunches. As for dry matter yield, Eragrostis curvula had the best performance with 5298.5 kg/ha.

This study addressed spacing between furrows and plants in the cultivation of the quinoa variety Patacamaya. This study took place from 1999 to 2000 in the Mamani community, Ingavi, La Paz, Bolivia. The Patacamaya variety is a cross between Samaranti (sweet) and Kaslala (bitter), with a vegetative cycle of 145 days (semi-early). It has large grains, is sweet, and has a high grain yield. The spaces between furrows were 40, 60, and 80 cm in an experimental design of randomly divided plots with four repetitions. The spaces between furrows were implemented in large plots and the plant spaces as sub-treatments in small plots. The results showed that the height of the plants were similar in all treatments except for T1 that was 35% lower compared with the other treatments. The highest grain yields occurred in treatment T6 with a value of 2,708.5 kg/ha, followed by T1 and T11. The lowest grain yields occurred in treatments T15, T10, and T5 with values of 1,124.3, 1561.4, and 1653.3 kg/ha, respectively.

In order to respond to the low economic and harvesting yields caused by diseases that attack the tomato, we considered using tomato varieties resistant to late blight (Phytophthora infestans) of tomato (Lycopersicon esculentum) and potato (Solanum tuberosum). The evaluation of the percentage of infestation was performed with tomato leaflets over a 168 hour period. The percentage of infestation was recorded every eight hours from the time of inoculation until maximum infestation was reached. The methodology applied was at random and included six treatments and five replications. The experiment consisted of collecting healthy leaflets from five improved varieties and one local variety of tomato. After collection, the leaflets were disinfected and inoculated in petri dishes on both sites of the midrib with Phytophthora infestans at concentrations of 1 x 107 conidium/mL. The commercial variety (Santa Cruz Kada Gigante) presented the lowest average infestation rate (50%) during the evaluation stage from time of inoculation up until 120 hours. After 120 hours, the leaflets of this variety also reached maximum infestation. A comparison of the study conditions to the scale of resistance values shows it must belong to a moderately resistant variety with horizontal resistance genes to this fungal disease.

Edible mushroom production has two different stages: the vegetative stage and the fruiting stage. The vegetative phase is performed in a biotechnology laboratory and covers the technique for obtaining “spawns”, which parameters include the multiplication and reproduction of the mycelium. The fruiting phase begins with the appearance of edible mushrooms and includes everything that occurs outside the laboratory. In our country, production of edible mushrooms is limited and generally unknown. So, in this study, the vegetative phase was divided into two stages and conducted in the laboratory. Stage 1: We inoculated spores and implants of the edible mushroom species Agaricus in three synthetic growth mediums: PDA (Potato-Dextrose-Agar), PDY (Potato-Dextrose-Yeast), and MEA (Barley-Biphosphate Potassium-Agar). These were incubated in different growth chambers at three different temperatures (17ºC, 20ºC, and 25ºC). The best mushroom development in terms of micellar growth was obtained in the PDA growth medium. The temperature that contributed most favorably to this development was 17ºC. Stage 2: We re-inoculated implants from the crops of the previous step in four natural substrates (brown rice, barley creole, brown rice combined with horse manure, barley combined with horse manure) and incubated them in growth chambers at three different temperatures. It was observed that the best micellar growth occurred in the natural substrate containing barley creole. Also, the most effective incubation temperature was 20ºC. Thus, we established that the barley grains sold in our city work well as a cheap natural substrate to propagate and produce edible mushroom “seed” of the Agaricus species at a temperature of 20ºC.

The peanut is an important crop in most countries due to its industrial, nutritional, and pedological potential. It grows well in subtropical areas. This study was planned based on the weather characteristics of the Yungas and the St. Felix community. A completely randomized block design with 6 treatments and 3 repetitions was used. An analysis of variance and a Tukey test were used for statistical analysis of the variables. With respect to time required for maturation, the Coloradito Palmar variety was most premature with a time of 134 days while the Local variety took 177 days to mature, which is considered late. With respect to plant height during the different stages (establishment, vegetative, flowering, fructification, and maturation), the Local variety grew the most with a value of 64.23 cm during physiological maturity. The Local variety also had the largest number of pods per plant with a value of 49.50. On the other hand, the Coloradito Palmar variety had the lowest value with 17.07. The largest number of grains per pod was reached by the Coloradito Palmar variety with a value of 2.35 and the smallest number was reached by the Colorado Gigante variety with a value of 1.66. The Overo Gigante variety had the largest values for pod and grain weight with 4.54 g and 1.77 g respectively. The smallest pod weight was obtained by the Coloradito Palmar variety with a value of 2.47 g while the smallest grain weight was obtained by the Local variety with a value of 0.78 g. With respect to pod length, the Colorado Gigante variety was longest at 4.25 cm and the Virginia variety was shortest with a measurement of 3.27 cm. The varieties that had the largest seed or grain size were Colorado Gigante and Overo Gigante with a size of 2.04 cm while the Coloradito Palmar variety had the smallest measurement of only 1.52 cm. Furthermore, the Virginia variety had the highest yield at 2.89 t/ha and the Coloradito Palmar variety had the lowest at 0.71 t/ha. After analysis, the total cost of production for each variety is 8,620 Bolivianos/hectare. The analysis of the cost-benefit ratio showed that only the Virginia (1.58) and Local (1.30) varieties would be profitable due to their higher yields. Thus, these varieties can be considered as an economic alternative for farmers in the area.

This study was conducted in the experimental unit of the Benson Agriculture and Food Institute, which is located in the Letanias community of the Ingavi province in the department of La Paz. Our objective was to compare the agronomic performance of two baby lettuce varieties (Lactuca sativa L.) at three planting densities in panqar huyus. In order to provide the rural farmer communities of Contorno Letanias and Contorno Medio a possible cost-effective alternative and to employ the use of moderate environments called panqar huyus, we introduced two varieties of baby lettuce: 1) Little Gem in seed form and 2) Tom Thumb already sprouted. These two were planted at densities of 250,000, 333,333, and 500,000 plants/hectare. Statistical analyses performed using the F-test and Duncan’s Multiple Range test found statistical differences between the varieties of baby lettuce and/or planting densities in the following response variables: plant height, number of leaves, root length, total foliage area, green foliage yield, and individual weight of green foliage. The values we obtained for green foliage yield were below those published by the European Union (2004). This was mainly due to the climate of the interior of the panqar huyus. The highest average yield achieved by the baby lettuce varieties was reached by Little gem in seed form with a value of 1.66 kg/m2. As for the planting densities, the highest yield was obtained with the 500,000 plants/hectare density, which had a value of 2.18 kg/m2. As for the quality of the harvested product, the values closest to the parameters established by the European Nations (2004) and the MAG/IICA (2004) were obtained in treatments 5 and 6. Some of these parameters were head diameter, plant height, number of leaves, total foliage area, and individual weight of green foliage. Furthermore, the economic analysis done via the partial budget estimate proposed by CIMMYT (1983) determined that treatment 5 (Little gem in seed form planted at a planting density of 500,000 plants/hectare) is the most profitable when compared to the other treatments in the area of domain.

Development and Biological Assessment of Fortified Foods with Andean Tubercles and other products in the Candelaria Area. An alimentation survey was carried out in the Rodeo Alto-Candelaria zone, a producing region of tubercle andinos, and a list was made of available products and other products which are a part of the local diet. With the list as the basis, 12 mixes were formed, combining tubercle (potato, goose, papalisa), cereals (quinoa, corn, and wheat) and legumes (tarhui, bean, and peanut). These mixes were submitted to a chemical and biological analysis, which indicated an increase in weight, PER, digestibility of the protein and energy. Seven mixes were chosen, using the highest values of biological parameters studied, especially the digestibility of the protein and energy, whose values fluctuated between 71-82% and 87-91% respectively, compared with a witness diet (milk). Leaving the chosen mixes aside, a prescription of products was formed, like: breakfast, laguas, and stew. In this, it was taken into account, eating habits, simple elaboration techniques and available products in the zone. The prescriptions present calculations of the protein and energetic values, which cover in a great percentage that requirements established by the FAO (1991) for the infant population.