Adjusting cotton pickers

Losses in cotton harvesting in different space settings between pressure plates and displacement speed show that any change in settings is sufficient to change the amount of losses and the final quality of the harvested product.

Harvesting, the last stage of the production process in the field, is the moment when the producer awaits the return on his investments and work. However, in many cases, higher yields are not obtained due to a lack of suitable machine or climate conditions, which leads to crop losses. Losses can be partially avoided or, to a large extent, minimized, if some care is taken in relation to the harvester, such as strict monitoring of work speeds, adjustments, plate adjustments, correct cleaning, knowledge and maintenance of onboard electronics, periodicity maintenance and replenishment of grease, water and detergent in the humidification system.

In the harvesting process there are two types of losses, quantitative and qualitative. Losses in quantity are exemplified by cotton that is on the ground due to several factors, cotton that remains on the plant after the harvester passes and loss of weight of open bolls due to delay in harvesting. One of the problems with cotton is the presence of impurities in the already harvested fiber resulting from the harvesting process. Therefore, it is extremely important to control the content of stem and leaves in cotton for productivity in the spinning process.

A study was carried out at the Federal University of Mato Grosso with the aim of presenting a working speed combined with mechanical adjustment on the platform, more precisely on the pressure plates, which reduces the quantitative and qualitative losses of cotton fiber. The main function of the pressure plate is to press the vegetable capsules and cotton against the spindles. The gap between the spindles and the plate must be 3mm to 6mm. Recommendations indicate that the ideal gap is around 4mm. If this space is smaller than recommended, the spindles may touch the plates and cause sparks and the start of fire in the harvested cotton; Incorrect adjustment also leads to losses of cotton in the field and facilitates the bushing of the units. The adjustment must be uniform across the entire pressure plate.

The space between the pressure plate and the spindles must be regulated in the field according to the characteristics of the crop at the time of harvest, taking into account the moisture of the plume and seed, architecture and height of the plant, productivity, variety, harvest time, among others. .

FIELD WORK

The work was carried out on a property in the municipality of Primavera do Leste (MT). Cotton was harvested with row spacing of 0,90m, of the 944 GL – Bayer variety. The machine used was a harvester of the type picker Montana brand, model cotton blue 2805. Three harvesting speeds were evaluated (V1 = 3,67km/h; V2 = 4,96km/h and V3 = 5,76km/h) and two spaces between the pressure plates and spindles (3mm and 6mm). Using a demarcation with a known area of ​​9m² (5m x 1,8m), all the cotton present in the plants and all the cotton on the soil surface were manually collected to compose the productivity and loss samples. After the harvester passes through the plot, using the same 9m demarcation², post-harvest losses were obtained. These losses are related to the cotton that, after passing through the machine, is retained in the cotton plant or is dropped to the ground by the action of the machine.

To determine qualitative losses, samples of cotton seeds were collected from inside the harvester basket. The impurities present in these samples were manually separated into two categories (stem and peel). The space between the pressure plate and the spindles must be adjusted to remove the maximum amount of feathers, without mechanically damaging the plant due to remains of stems, branches and other contaminants.

RESULTS OBTAINED

The percentage of impurities for the 6mm space ranged from 2,01% to 2,29% and for the 3mm space it ranged from 2,93% to 3,28%. The space between the plates and the spindle and the increase in speed reduced by approximately 29,39%; 38,71% and 21,81%, respectively, the amount of impurities in the cotton load. It is interesting to note that, regardless of the operating speed, the greater space between the plate and the spindle resulted in a greater amount of impurities in the samples.

The percentage of stem for the variation of spaces between the plates and the spindle varied from 0,51% to 0,65% for the smallest and largest distances, respectively. Plates with a 3mm space increased the percentage of stems in the harvested fiber by up to 21,5%.

Graph 3 presents data related to displacement speed for the variable presence of stem. It can be observed that regardless of the speed of movement, there were no differences in the amount of stem in the cotton load.

The average loss values ​​presented in Graph 4 demonstrate that tightening the pressure plate reduces cotton losses (7,76%) compared to the non-pressure plate (10,28%). Regardless of the values ​​found related to losses, it is noted that these values ​​are above the acceptable 5%.

The results of cotton losses due to the variation in speeds are presented in Graph 5. It is observed that at the lowest speed (3,67km/h) the greatest losses occurred with a value of 10,23% and at the highest speed (5,76. 8,12km/h) the lowest loss occurred with a value of 4,96%, not differing from the speed (XNUMXkm/h). The greater loss at the slower speed may be due to the longer time that the plant remains in the harvesting units.

The greater space between the pressure plates and the spindles reduces the number of stalks in the cotton. The reduction of stems present in the fiber increases its quality, as during processing the fiber will be less attacked to remove the branches present in smaller quantities. The higher travel speed results in greater harvester efficiency, as it is at this speed that the lowest losses occur.

Hiago Henrique R. Zanetoni, Renildo Luiz Mion, Nayra Fernandes Aguero, Cíntia Michele Baraviera, Renato Bassini, Willian Lima Crisostomo, Carlos Alberto Viliotti, Myllena Teixeira, Luiza Cabral, UFMT

Article published in issue 163 of Cultivar Máquinas.