Search

The aim of this paper is to analyze the quality of the mechanical harvest of rice seeds, carried out by the New Holland L521 rice harvester machines, at the Rice Farm "Los Palacios". Their technological parameters were evaluated depending on the quality of the harvested product, taking into account some aspects such as: the entire, peeled and/or broken grain, the impurity content and total losses. This resulted in values of 5,2-6,4% for peeled and/or broken grain in the five agricultural yields. On the other hand, the impurity content was among 8,3-9,6%, so that both parameters exceed the established limits. This is mainly caused by: the bad regulation of thresh, the work speed and the poor training of operators. These results allow decreasing losses. During the harvest losses decreased from 206kg/ha to 85kg/ha which represents an economic effect of $ 316 202.04 pesos. This also permits to stop investing about 184 793.4 USD on rice for our population feeding. [ABSTRACT FROM AUTHOR]

In the Havana agriculture the sustainability of soybean production is affected by the high variation of the seed quality and harvest losses, due to the lack of integration of the agronomical and technological factors during the soybean production. It was demonstrated that harvest losses were as high as 30 % of the potential yield. In this paper an evaluation of mechanical harvest on the varieties Conquista, IGH-24 y V9, seeding in Havana fields is presented. It was founded that the total losses during soybean harvesting reached values from 42,86 kg/ha a 690,36 kg/ha and that the plant density highest to 200 000 plant/he increase the height plant as well as the insertion of the first pods in the stem; it contributed to reduce the gathering losses level. With the application of the Principal Components Analysis (ACP) was proved that 82,272 % of the total variability was accumulated in the three first components and the variables that showed the greatest contribution were: the threshing losses (%), the weeding intensity (%), the gathering losses (%), the plant height (cm), the seed humidity contents (%), the insertion of the first pods in the stem (cm) and the plant density (pl/he). The correlation matrix among these variables indicated that the variable most influence in the efficiency to this operation was that weeding intensity because it was correlated positively with the total losses, the threshing losses, the gathering losses, as well as the seed humidity contents and the plant height. As result, the implementation of correctives measurements related to the harvesting machine working regime, the harvest losses were reduced in more than a half. [ABSTRACT FROM AUTHOR]

Coffee harvesting with the aid of mechanical means becomes impracticable for the immense majority of coffee producers in the world, due fundamentally to that, in general, in the moment of the crop, the plants contain fruits in all their maturation status and have not been able to be developed machines that guarantee a selective detachment of the cherries during harvest operation. In a first study (Symposio do Café do Brasil. EMBRAPA), a modal analysis of coffee fruit-stem system was made. Starting from this analysis, the possibility of achieving the selective detachment of the fruits (removing of a high percent of mature fruits and low percent of immature ones) can be expected if the vibrating frequencies of the machines that use this work principle, are selected in the surrounding of a vibration mode "in contrafase" of the fruit-pedicelo-peduncle system. In this first study, an analysis of the first twelve vibration modes of different configurations of the fruit-pedicelo-peduncle system of coffee, was carried out. This study resulted enough for the analysis of configurations with one fruit for peduncle, but it was insufficient for an analysis of the behavior of configurations with two or three fruits for peduncle. In this paper an study of 25 vibration modes of fruit-pedicelo-peduncle system of coffee (coffea arabica) varieties "Red Caturra" and "Yellow Caturra" is presented. As a result of the study four variants of counter-phase vibrating mode of the fruit-pedicelo-peduncle system were founded, being able to recommend the more promissory mode for selective harvest of coffee. [ABSTRACT FROM AUTHOR]

Recent studies involving selective coffee harvesting by shaking, indicates the necessity to apply to fruit -- stem system significantly high excitement frequencies in comparison with those that are habitually applied at the international practice. To reach the predicted frequency levels, in the order of 150-200 Hz, by mechanical, hydraulic or pneumatic means, is very difficult due to the presence of friction couples in these types of mechanisms that would suffer premature waste by the relative high speeds. It's for this reason that the development of electromagnetic vibrators in which the inertial mass, when moving inside a magnetic field, avoid the direct friction among kinematical couples, is a current task. In this paper, the mathematical modeling of a vibratory system of two degrees of freedom is made, using the method of the mechanical impedance, in order to obtain the frequency response of the system, and to determine the design parameters of a shaking device able to achieve certain levels of amplitude of the vibrations at the high required frequencies. From the study also emanates the conclusion that in such shaking device, the natural frequencies of the vibratory system should be contained in the range of the exciting force frequencies. [ABSTRACT FROM AUTHOR]

Researches directed to increase the indicators of efficiency and quality during coffee harvest mechanization constitutes an important topic at present time. The determination of the physical-mechanical properties of fruits and fruit-stem system is an indispensable stage during these investigations. In this paper the results on the determination of a group of dimensional, inertial and elastic properties of the fruit-stem system of coffea arabica variety Catuai in different ripening stages, related with mechanical harvesting of this crop, are presented. Also, the bending moment required for the rupture of the fruit-stem union is determined. Methods of processing of digital images, as well as strain gages techniques were used during the investigation. As result of measurement of the different properties, substantial differences on dimensional, inertial and elastic characteristics of green and ripe fruit were found, like as in the bending moment required to fruit detachment and in the detachment patterns. [ABSTRACT FROM AUTHOR]

The paper tries a calculation methodology of the productivity of the rice harvester in function use of shift time, when the same ones work for the outline of circular movement. During the calculation of the productivity they are kept in mind the parameters and work regimen of the machines, what allows to specify the factors in which it is necessary to influence to diminish the losses of time of useful work and consequently to elevate the productivity of the harvesters. [ABSTRACT FROM AUTHOR]