Considerando que a colheita é a etapa final de um processo produtivo e que as perdas devem ser mantidas dentro de padrões aceitáveis, as regulagens das colhedoras e as características agronômicas da cultura deverão permitir menores perdas quantitativas para que possa atingir o máximo nível de qualidade e maior sustentabilidade do sistema produtivo. Este trabalho teve como objetivo determinar as perdas quantitativas, distribuição de palha e características operacionais da colhedora por meio do controle estatístico de processo, bem como verificar a qualidade da operação de colheita. O trabalho foi realizado no município de Santa Juliana (MG), com as coordenadas geográficas de referência 19º 18'Se 47º 31'O. A área amostrada constou de 40 pontos distribuídos em malha retangular, equidistantes de 50 m, definidos sequencialmente a partir do momento de início da colheita. Em cada ponto foi determinado o teor de água dos grãos, número de vagens por planta, altura de inserção de primeira vagem, altura de plantas, produtividade, distribuição de palha e características operacionais da colhedora. A perda de grãos ocasionada pela colhedora esteve fora dos limites de controle, porém dentro dos padrões aceitáveis de perdas para cultura da soja. A qualidade da operação de colheita e as regulagens da colhedora foram dependentes da velocidade de deslocamento. A distribuição de palha esteve próxima do desejável para o sistema de semeadura direta. A utilização das cartas de controle foi eficiente na identificação dos pontos fora de controle e na avaliação da qualidade do processo de colheita.

O sistema de colheita mecanizada pode buscar melhorias no processo utilizando ferramentas de qualidade e auxiliar na redução de perdas, aos danos à soqueira e aumentar a longevidade do canavial. O objetivo deste trabalho foi detectar o controle efetivo da variabilidade das perdas e danos à soqueira, bem como identificar se estas estão dentro dos padrões aceitáveis. Para tanto, foram amostrados 40 pontos em dois períodos de colheita, diurna e noturna, em malhas retangulares (55 x 45 m) para determinação das perdas visíveis (rebolos repicados e estilhaçados, pedaço fixo e solto, toco e estilhaço), utilizando-se armações de 10 m². Foram mensurados a altura de corte e os danos na soqueira (sem danos, danos parciais e fragmentados). A estatística utilizada foi descritiva para as variáveis perdas de cana-de-açúcar no período diurno (D) e noturno (N), além da análise de variância, utilizando-se o teste F a 5% de probabilidade e o teste de Tukey para comparação de médias e a utilização de controle estatístico de processo por meio de cartas de controle de processo. Não houve diferença quanto a danos na soqueira. No processo de colheita, as perdas por rebolo repicado e estilhaçado foram consideradas estáveis (sob controle), assim como as perdas por toco, enquanto as perdas por pedaço fixo e solto, estilhaço e cana-inteira ficaram fora de controle. A altura de corte e as perdas totais foram maiores durante a colheita noturna. As cartas foram eficientes para a avaliação de controle do processo de colheita diurno e noturno.

Mechanized coffee harvesting is one of the main technological advances that benefit producers, but problems with planning for planting and crop development and faults in harvester adjustment can reduce the efficiency of the operation, making it more stressful for the crop than manual harvesting. Thus the present study was carried out in the municipality of Patos de Minas, MG, Brazil with the objective of assessing the damage in the vegetable part and the quality of the mechanized harvesting of coffee cropped in a circular planting system under a center pivot, with two rod vibration frequencies and statistical control of the process. It was observed that the negative biennially on the crop reduced the initial coffee load eliminating the effects of the insolation conditions. The harvest quality indices were distributed asymmetrically and the samples varied greatly and only the stripping efficiency was influenced by the axles assessed and were shown to be stable by the statistical control. The damage to the plants by the harvester presented desirable values and did not vary in function of the factors analyzed, but was considered under statistical control.

The peanuts harvesting mechanization is affected by the soil physical characteristics and it may increase the losses due to the production of pods in subsurface. The objective of the experiment was to identify the clusters through multivariate exploratory approaches from similarity in six soil textures (very clayey, clayey, silty clayey loam, clayey loam, sandy loam and sandy) in the state of Sao Paulo, Brazil, determining the main agronomic variables that most influenced the clustering division to assist the decision-making process in peanuts mechanized harvesting. The data were analyzed by the multivariate exploratory that is performed to simplify the description of a set of interrelated variables, using: yield, maturity, soil and pod moisture content, windrow width and height, visible and invisible digging losses, and gathering losses, as agronomic indicators of quality. The low and high clay content were grouped into clusters I and III, respectively, according to the agronomic traits of the peanut crop. The principal components analysis (PC) allowed a single distribution of accesses since only two eigenvalues were higher than "one": the highest eigenvalues of 4.51 and 1.79, resulted in a Biplot that explained 70% of the original variability, 50.11% and 19.89% of which in the PC1 and PC2, respectively. The multivariate analysis indicated that high peanut yields in soils with low clay are correlated with the losses during the peanut mechanized harvesting operation.

Among the factors that may influence corn yield are sowing operation direction and plant population, since they alter the shade index between crop rows, and consequently the efficiency of interception of the photosynthetically active radiation by the leaves of plants. The aim of this study was to evaluate the influence of sowing direction and plant populations on P2830VYH hybrid corn yield. The experiment was conducted at the facilities of FCAV-UNESP, latitude 21º 14’ S and longitude 48º 16’ W in Jaboticabal (SP). The treatments were composed of three sowing directions (North-South, Northeast-Southwest, and East-West) and three population densities (40,000, 60,000 and 80,000 plants ha^-1). The treatment with 80,000 plants ha^-1 had the lowest cost per sack of corn and profitability 21% higher than that of the treatment with 60,000 plants ha^-1, and 45% higher than that of the treatment with 40,000 plants ha^-1. Sowing direction had no influence on grain yield when environmental conditions were favorable to the development of the crop. Lower plant densities lead to higher individual results in relation to the number of cobs, length of cobs and number of grains per row.

The Technologies setting at Agricultural production system have the main characteristics the vertical productivity, reduced costs, soil physical, chemical and biological improvement to promote production sustainable growth. Thus, the study aimed to determine the variability and the linear and special correlations between the plant and soil attributes in order to select and indicate good representation of soil physical quality for forage productivity. In the growing season of 2006, on the Fazenda Bonança in Pereira Barreto (SP), the productivity of autumn corn forage (FDM) in an irrigated no-tillage system and the soil physical properties were analyzed. The purpose was to study the variability and the linear and spatial correlations between the plant and soil properties, to select an indicator of soil physical quality related to corn forage yield. A geostatistical grid was installed to collect soil and plant data, with 125 sampling points in an area of 2,500 m². The results show that the studied properties did not vary randomly and that data variability was low to very high, with well-defined spatial patterns, ranging from 7.8 to 38.0 m. On the other hand, the linear correlation between the plant and the soil properties was low and highly significant. The pairs forage dry matter versus microporosity and stem diameter versus bulk density were best correlated in the 0-0.10 m layer, while the other pairs - forage dry matter versus macro - and total porosity - were inversely correlated in the same layer. However, from the spatial point of view, there was a high inverse correlation between forage dry matter with microporosity, so that microporosity in the 0-0.10 m layer can be considered a good indicator of soil physical quality, with a view to corn forage yield.