Seed Coat Damage Research Articles

Genetic variability for susceptibility to seed coat mechanical damage and relationship to end‐use quality in kidney beans

AbstractKidney beans (Phaseolus vulgaris L.) have strict market specifications for seed and end‐use quality. One major quality concern is the appearance of cracks, also termed checks in the seed coat caused by mechanical damage occurring during harvest and postharvest handling. Genetic variability for seed coat checks (SCCs) has not been well characterized in kidney beans. The objectives of this study were (1) to test an existing screening method for easy assessment of seed coat mechanical damage, (2) to explore the genetic variability for mechanically induced seed coat damage in kidney bean and its relationship to seed coat thickness, (3) to characterize the relationship of SCC to end‐use quality, and (4) to identify potential germplasm resources for genetic improvement. A collection of dark red, light red, and white kidney beans were grown over 2 years and harvested with two threshing methods to mimic mild and severe treatments of mechanical damage. Belt threshing produced mild damage, and combine threshing produced severe damage. Seed coat thickness was not correlated with SCC of the combine‐threshed beans but was negatively correlated with the belt‐threshed beans at r = –0.33. Seed moisture content played an important role in SCC. Higher SCC severity scores resulted in lower canning quality appearance scores (r = –0.51). The SCC severity score of combine‐threshed seeds can be used as a selection factor in variety improvement for resilience to mechanical damage. Genotypes with low SCC severity score were identified for breeding initiatives.

Soil grit influences the effects of earthworms (Lumbricus terrestris) on seed damage

Ingested soil grit is thought to enhance the grinding action of the earthworm gizzard but its role in earthworm-seed interactions is unknown. This study used feeding trials to investigate how different levels of supplemental soil grit (+0 %, +25 %, and +50 % sand additions by weight) influenced the impacts of the cosmopolitan anecic earthworm Lumbricus terrestris L. on seed ingestion, egestion, seed coat damage, and germination of garlic mustard (Alliaria petiolata). Added grit increased the amount of seed coat damage on garlic mustard seeds egested by L. terrestris. Earthworm egestion also increased the speed of garlic mustard germination (∼20 days control, ∼14 days with L. terrestris and +0 % grit, ∼11 days with L. terrestris and +25–50 % grit). The results demonstrate how earthworm ingestion and soil grit can modify the impacts of earthworms on seeds and highlight the importance of considering soil texture in field and laboratory earthworm experiments.

The Effect of Seed Source and Post-harvest Practices on Quality of Soybean (Glycine max) Seeds in Busia County

Majority of farmers growing legumes use and recycle seeds from informal sources for the next crop. The quality of such seeds is unknown and usually leads to accumulation of pest, diseases and reduced yields. This study was carried out to determine production practices and quality of soybean seeds obtained from informal sources in Busia County. A survey was conducted to collect information on source of soybean seeds, production and post-harvest handling practices. Seed samples were collected from farmers, local market and agro-dealers. The seeds were evaluated for purity, seed coat damage, germination, vigour and fungal infection. Majority (48%) of farmers in Busia County used farm saved seeds, 29% and 23% used seeds from community based organizations and local markets, respectively. Most of the farmers (92%) used inappropriate threshing techniques like beating with sticks and about 80% of the farmers did not treat seed either before storage or during planting. Majority (68%) stored soybean for three months only. Seeds from informal sources had low purity, higher seed coat damage and infection as compared to certified seeds. The physical purity of seeds from the informal sources did not meet the recommended standard of 98% however their germination was comparable to 75% germination standard. Farmers therefore, should be advised to adopt use of certified seeds and appropriate handling techniques. Keywords: Soybean, seed source, seed quality, seed production practices

Performance assessment and optimization of maize dehusker cum sheller - A technology for Northern Transition Zone of Karnataka

Maize (Zea mays L.) is one of the major crops in Karnataka state grown for commercial and seed-production purpose. In Northern Transition Zone (Hyderabad-Karnataka region), the major farming sizes of land are limited small to medium holding and they were in the need of economical technique for maize dehusking and shelling operation suited to medium capacity. In present study, the medium sized electric motor (2.23 kW) operated maize dehusker cum sheller (MDS) was developed and evaluated for selected operational parameters, viz. cylinder peripheral speed(6.2, 6.6, 7.1 and 7.6 m/s), concave clearance (20, 25, 30 and 35 mm) and feed rate (400, 600 and 800 kg/h). The machine performance parameters revels that, the dehusking efficiency and shelling efficiency were showed increasing trend with cylinder peripheral speed (S) from 6.2 to 7.6 m/s; whereas decreasing trend against increase in Concave Clearance (C) from 20 mm to 35 mm. The total losses of grains in machine were found lowest between feasible at 25 to 30 mm of C for all feed rates (F). In seed-quality parameters, the decreased germination percentage with increase in S was observed. The increased broken grains (%) and seed-coat damage (%) were identified with increased inS and decrease in C as well as F. The highest desirability value (obtained from numerical optimization technique) was obtained for operational parameter combination of S at 7.1 m/s with C at 25 mm under 600 kg/h of F. The total cost of the MDS was ` 34500 with benefit-cost ratio of 2.24. The performance of machine was also satisfactory for producing maize seeds for seeding purpose without compromising its performance.

Anatomical and micromorphological characteristics of the seed coat of field pea (Pisum sativum L.) genotypes in relation to cracks and damage of seeds

In this paper, we present the morphological characteristics of the seed and micromorphological, anatomical and chemical characteristics of the seed coat of pea (Pisum sativum L.) genotypes, Jezero, Javor and NS Junior. Our aim was to investigate whether these genotypes can be differentiated based on seed coat morphoanatomical characteristics, depending on the harvest treatment. The observations and measurements of seed coat cross-sections were performed using light microscopy. The seed coat surface was observed using SEM. A tuberculate seed coat surface characterized all examined pea genotypes, and the average diameter of the tubercle was about 12 ?m. Statistical and laboratory analyses revealed that major damage was the most frequent defect type as the result of mechanized harvest in all the examined genotypes. Genotype NS Junior had the shortest seed length (6.1 mm). Micromorphological analysis revealed that the seed surface was tuberculate in all genotypes. The genotype Jezero had the highest number of tubercle ribs (11.0) and a significantly higher proportion of parenchyma tissue (50.6%), while NS Junior was characterized by the greatest share of macrosclereids (49.8%). The highest number of osteosclereids (832/mm2) was counted in genotype Javor. In addition, genotype NS Junior stands out due to the highest percentage of crude fiber (62.75 g/100g) in the seed coat. There was a marked difference among the studied genotypes with regard to the seed coat morphoanatomical characteristics, which is confirmed by the results of multivariate discriminant analysis (MDA). These results suggested that the morphological, micromorphological and anatomical characteristics of the seed might have an impact on the seed coat damage level at harvest.

Identification of soybean seed coat damage.

The objective of this research was to evaluate the tests for detection of mechanical damages in soybeans seeds. Thus, it was compared the use of sodium hypochlorite solution (2.0% and 5.25%), water and tetrazolium solution (0.075%). The study was conducted in soybean seeds, from the cultivars Embrapa 48 and FTS Aguia with, respectively, 8.08% and 6.06% of lignin on seed coat, which were harvested mechanically and manually. The seed quality was evaluated by water content, germination and vigor (tetrazolium and electrical conductivity tests). The mechanical damages in soybean seeds, of immediate effect, can be determined by the use of the 2.0% sodium hypochlorite solution.

Identification of soybean seed coat damage

The objective of this research was to evaluate the tests for detection of mechanical damages in soybeans seeds. Thus, it was compared the use of sodium hypochlorite solution (2.0% and 5.25%), water and tetrazolium solution (0.075%). The study was conducted in soybean seeds, from the cultivars Embrapa 48 and FTS Águia with, respectively, 8.08% and 6.06% of lignin on seed coat, which were harvested mechanically and manually. The seed quality was evaluated by water content, germination and vigor (tetrazolium and electrical conductivity tests). The mechanical damages in soybean seeds, of immediate effect, can be determined by the use of the 2.0% sodium hypochlorite solution.

CROP AND HARVESTING OPERATION CHARACTERISTICS AFFECTING FIELD LOSSES AND PHYSICAL QUALITIES OF SOYBEANS – PART I

This study evaluated the effects of soybean moisture content, stink bug and weathering damage, and combineground speed, age, and threshing cylinder rotational speed on seed breakage/splitting, seed coat damage, material other thangrain content (MOG), and field losses. There were significantly more broken/split seeds at moisture contents below 12% andsignificantly less seed coat damage above 14%. There were positive linear correlations between moisture content andweathering damage, threshing cylinder rotation speed, and MOG; a negative linear correlation between moisture contentand broken/split seeds; and a non-linear (quadratic) correlation between moisture content and field losses. Stink bug damageup to 6% resulted in significantly less broken/split seeds, seed coat damage, and MOG. Stink bug damage correlated linearlyand positively with each of the three response variables. Weathering damage up to 6% resulted in significantly lessbroken/split seeds and seed coat damage. Weathering damage also correlated linearly and positively with broken/split seeds,seed coat damage, and MOG. Combine ground speeds above 5.5 km/h resulted in significantly more seed coat damage andless MOG. Ground speed correlated linearly and positively with seed coat damage, linearly and negatively with MOG content,and non-linearly (quadratic) with field losses. There were no significant differences between the two levels of combine agefor any of the response variables. However, there was significant linear correlation between combine age and field lossesshowing trends for obtaining lower field losses with newer combines. Threshing cylinder rotational speeds up to 600 rpmresulted in significantly less broken/split seeds, seed coat damage, and MOG. Threshing cylinder rotational speed alsocorrelated linearly and positively with all three response variables.

SELF-PROPELLED PROTOTYPE SOYBEAN HARVESTER

A four-row self-propelled prototype of a new and simplified concept soybean harvester was built and field testedas part of a major project carried out for several years. The prototype threshes soybeans from standing, uncut plants usingimpact energy provided by plastic fingers mounted on opposite rotating shafts, and uses a pneumatic system for capturing,separating, cleaning, and transporting the beans. Compared to ten different combines from each of three brands withconventional tangentially fed threshing systems, and ten different combines from a brand with an axial-flow threshing system,the prototype-harvested seeds were significantly better with respect to broken/split beans and seed coat damage than all thecombines with tangentially fed threshing systems. The amounts of material-other-than-grain (MOG) in the samples harvestedwith the prototype were significantly less than for all conventional brands. The seed vigor of the samples from the prototypewas significantly better than those from one of the combine brands with a tangentially fed threshing system. Invisiblemechanical damage, germination, and grain field losses were not statistically different between the prototype and all combinebrands evaluated. The overall results confirmed the better quality of the collected beans, including that obtained with previousversions of the prototype. It also showed that the harvesting module, initially designed for small and medium-size farms, wasadaptable to a self-propelled unit and therefore to larger-scale operations.

Mechanical damage to soybean seed during processing

Abstract The effects of seed cleaning and handling on soybean seed germination and physical integrity were determined with changing seed moisture content (m.c.). In addition, storage behavior of seed and loss of storability caused by damage resulting from free-fall from different heights were determined. Six lots of the variety “MACS-13” at three different m.c.'s were passed through a vertical bucket elevator, cleaner with grader, and gravity separator and evaluated for mechanical damage, germination, and vigor index. The storage behavior of the lots, at different stages of processing, was studied by performing an accelerated aging test. The effect of free-fall on quality of the seed was studied by dropping six seed lots from four different heights on to cement and galvanized iron floors. The vertical bucket elevator significantly decreased germination and increased splits and seed coat damage. The seed lots at 12% m.c. (dry basis), suffered less loss in seed quality than the lots at 10% or 11% m.c. The storage quality of seed, as predicted by the accelerated aging test, at 12% m.c. was also better than the lots at 10% or 11% m.c. A free-fall of soybean seed from different heights on to the cement floor resulted in greater loss in quality than when dropped on to the galvanized iron floor.

Seed colour and linolenic acid effects on agronomic traits in flax

Solin flax (Linum usitatissimum L.) is an edible-oil crop that must have less than 5% linolenic acid in its seed oil and a yellow seed coat. Seed vigour of solin is often lower than that of brown-seeded linseed flax and this lower seed vigour has been associated with both seed colour and linolenic acid levels. To evaluate the agronomic affect of this relationship, paired near-iso-genic populations of flax differing in seed coat colour and linolenic acid concentration were selected from different crosses and sown in field trials at the Kernen Crop Research Farm, University of Saskatchewan in 1995 and 1996. Seed with brown seed coat colour had higher field emergence and seed yield than yellow-seeded types. However, emergence differences did not contribute to this seed yield variation. Maturity was not affected by seed colour but yellow seed had greater seed oil concentration and mechanical seed coat damage than brown seed. Low linolenic acid seed (2%), compared with high linolenic seed (50%), had lower field emergence in 1995, were later maturing and had higher seed yield. Linolenic acid concentration had no significant effect on oil concentration and seed damage from mechanical harvesting. Solin types had lower field emergence than industrial oil types. There was no difference for seed yield, oil concentration and seed weight between solin and industrial oil types. Solin seed was slightly later maturing and had greater seed coat damage than industrial seed in some genetic backgrounds. Key words: Seed colour, linolenic acid, emergence, seed damage, flax

Sirococcus blight: a seed-borne disease of container-grown spruce seedlings in Coastal British Columbia forest nurseries

Sirococcus blight, caused by Sirococcus strobilinus Preuss, was shown to be a seed-borne disease of container-grown Picea sitchensis (Bong.) Carr., P. glauca (Moench) Voss, P. engelmannii Parry, and P. glauca × P. engelmannii spruces. The fungus was best detected by germinating seeds from seedlots with consistent disease histories, in autoclaved soil mix in pots (kept at 16 to 20 °C, and at light intensities of 900 to 1800 lx), and isolating the pathogen from diseased seedlings. Seed-borne isolates of S. strobilinus were pathogenic to P. sitchensis seedlings. The pathogen was present on 0.3 to 3.1% of the seeds of infested seedlots. Seeds with shrunken contents yielded the pathogen seven to nine times more often than seeds with normal-appearing contents. Disease incidence was unrelated to seedcoat damage or prevalence of empty seeds. Histological examinations revealed presence of the pathogen throughout the endosperm and embryo tissues of diseased seeds. The results are discussed in relation to incidence of Sirococcus blight in Coastal, container nurseries.

Seed Coat Damage in Deep-Bed Drying of Soybeans

ABSTRACT SOYBEANS have been dried in batches up to 0.6-m. deep using drying air temperature of 50 and 65C and air flow rates of 0.102 and 0.203 m3/s-m2. Results indicate that initial moisture content, air flow rate, dry-ing air temperature and location within the bed all have a significant effect on drying damage.

Improved Indoxyl Acetate Test for Detecting Soybean Seedcoat Damage

ABSTRACT AN improved, indoxyl acetate test for detecting seed-coat cracks in soybeans was developed, test results were compared with results from use of sodium hypochlorite and tetrazolium tests. The indoxyl acetate test caused seeds to stain a blue-green color in the area of a seedcoat crack. The test was effective in finding higher levels of seedcoat cracks than the sodium hypochlorite and tetrazolium tests and detected minute seedcoat im-perfections in as much as 16 percent of the seeds that would have otherwise gone undetected by visual observa-tion alone. The indoxyl acetate test did not have any adverse effect on warm germination percentages of un-damaged seeds.

Studies on the germination and field establishment of Summit wheat

Poor field emergence of the wheat cultivar Summit was reported in the Wimmera Region of Victoria after its release to farmers in 1966. In field and laboratory experiments the emergence of Summit was reduced when seed was stored for long periods after being treated with normal rates of a phenyl mercury acetate fungicide commonly used for control of covered smut or common bunt of wheat. A shorter period of storage with higher rates also seriously reduced emergence. Several other fungicides were shown to have varying effects on the emergence of the cultivar and one of these, maneb, gave satisfactory control of bunt. The greater susceptibility of Summit to phenyl mercury acetate demonstrated in these experiments was not associated with the degree of seed coat damage.

Effect of Some Seed Characteristics on Mechanically Induced Seedcoat Damage in Navy Beans (Phaseolus vulgaris L.)

AbstractNavy bean seeds were evaluated for their response to mechanical abuse. Seed of all lines was hand threshed and equilibrated to a constant moisture content prior to damaging.Highly significant differences were found among lines in their reaction to seedcoat cracking. Seed weight, shape, density and seedcoat anatomy were examined as components contributing to seedcoat damage. Seedcoat cracking increased as the seed weight increased. Normal within‐line weight differences were small and self‐compensating, but between lines weight variation had a highly significant effect on cracking. Cracking also increased as the shape became more nonspherical. Increased seed density improved seedcoat tolerance to mechanical abuse but caused a nonsignificant increase in cotyledon splitting. Tolerant bean lines generally had a thinner parenchymatous layer underlying the osteosclerids. There was no difference in the thickness of the osteosclerid and macrosclerid layers between tolerant and susceptible lines.

Dehulling and Seed Germination in Vernonia Anthelmintica (L.) Willd.1

Fresh seed of four Vernonia anthelmintica (L.) Willd. selections were (1) untreated (N), (2) water soaked overnight (S), (3) soaked overnight followed by removal of pericarp (SP), or (4) soaked overnight followed by removal of pericarp and seedcoat (SPS). The SP treatment increased germination, but many abnormal seedlings resulted, probably due to seedcoat damage during dehulling. A considerable increase in germination followed the SPS treatment. Average shoot length of resulting seedlings approached that of the few normal seedlings after N and S treatments. The factor(s) inhibitory to the germination of fresh vernonia seed is associated with the seedcoat.