Physiological Quality of Soybean Seeds Under Mechanical Injuries Caused by Combines

Abstract

-The mechanical harvesting causes injuries on seeds and may affect their quality. Different threshing mechanisms and their adjustments may also affect the intensity of impacts that machines cause on seeds. So, this study aimed at diagnosing and evaluating the effect of two combines: the first one with a threshing system of axial flow and the other one with a threshing system of tangential flow, under adjustments of concave opening (10 mm, 30 mm and 10 mm for a combine with axial flow and 3.0 mm, 15 mm and 3.0 mm for a combine with tangential flow) and three cylinder rotations on the quality of soybean seeds harvested at two moisture contents. Soybean seeds of cultivar 'ND 4910' were harvested at 16.6% moisture (mid-morning) and 13.7% moisture in the afternoon. The seeds quality was evaluated by germination tests, germination speed index (GSI), germination rate, moisture content, percentage of purity and vigor by tetrazolium test. Despite the combine, the results showed that the mechanical injury has most reduced seeds quality, at 16.6% moisture content, concave opening of 30 mm (axial) and 10 mm (tangential) and cylinder rotation of 1100 rpm (axial) and 1000 (tangential), both with the highest rotations used. The combine with tangential flow had the highest degree of seeds purity. When seeds moisture content at harvest was close to 13.7%, there was the highest seed injury, while, at 16.6%, there was the highest number of crushed soybeans, regardless the combine adjustment.

Evaluation of the effect of mechanical damage of seeds at different seed ages on faba bean (Vicia faba L.) seedling development and disease

“…Among the data from non-injured seeds 1-and 2-years old supported that idea. In one of the studies (Pacheco et al, 2015) [9] , soybean seeds were harvested at two moisture content (16,6% and 13,7%) and combine adjusted three different threshing (highest, lowest, and ideal). Their results showed that the lesser moisture content and the highest threshing caused significantly broken seeds, lesser seed viability, seed vigor, and germination capacity.…”

“…In addition, not only visible damage, but also invisible damage can affect seed physiology, quality, seedling, and full-grown plant growth. Most of the studies on this subject have been on seed damage caused using mechanical tools or combines during harvest (Pacheco et al, 2015;Govindaraj et al, 2017;Gu et al, 2019) [9,6,7] . There are some studies and reviews that indicate the effects of mechanical injury on increasing infection (Bell, 1974;Lamichhane et al, 2020;Rehman et al, 2021) [3,8,10] .…”

Immediate and latent effects of drying soybeans with dehydrated air

“…Similarly, Souza, Albuquerque, Zorato and Carvalho (2009), analysing mechanical damages and quality of cotton seeds, found that the cuts and deep fissures, including those that reach the embryo, lead to reductions in seed germination and vigour. Still, Pacheco et al (2015), studying physiological quality of soybean seeds under mechanical injuries caused by combines, have realized that the mechanical injury has most affected seed quality reductions.…”

A comb-brushing-type green soybean pod harvesting equipment: Design and experiment

“…With the interaction effect between plants and harvesting rollers, the soybeans are harvested. After material delivery, blade cleaning, impurity removal, and pod collection, the mechanized harvesting of green soybean plants is realized [ 14 ]. The harvester using a vertical roller has the advantages of simple structure, one-stage sorting, detachment rate of 92%, and damage rate of 20.8%, however, it can only adapt to high ridge planting rather than flat planting and the damage rate is also too high.…”