Chemical Composition of Fir, Pine and Thyme Essential Oils and Their Effect on Onion (Allium cepa L.) Seed Quality

Botrytis allii and B. cinerea are important seed-transmitted pathogens of onion. The aim of this study was to determine the chemical compositions of fir, pine and thyme essential oils and evaluate their effects on the germination, vigour and health of onion seeds. Gas Chromatography/Mass Spectroscopy was used for the analysis of the oils’ chemical compositions. Seed germination, vigour and health tests were performed on untreated seeds and on seeds treated with volatile compounds of the oils applied at a concentration of 0.2 µL cm−3 for 6, 12, 24, 48 and 72 h or at a concentration of 0.4 µL cm−3 for 3, 6 and 12 h. The main components of fir oil were bornyl acetate (55.5%) and α-pinene (15.6%), pine oil contained mostly α-pinene (35.5%) and β-pinene (18.6%), and thymol (34.2%) and p-cymene (26.2%) prevailed in thyme oil. Almost all treatments significantly reduced seed infestation with Alternaria alternata and Fusarium spp., and some effectively controlled Botrytis spp., however, seed health improvement was usually associated with deterioration of seed germination and vigour. Only treatment with fir oil at a concentration of 0.2 µL cm−3 for 6 h effectively controlled seed-borne pathogens and positively affected seed germination. Considering the beneficial effect of the oils on seed health, further studies are necessary in order to establish the optimal conditions for onion seed treatment.

Enhancing Seed Health for Organic Vegetable Production Systems: Challenges and Opportunities

Organic vegetable production is a rapidly expanding segment within the fast growing organic sector of agricultural production. Although pests and diseases remain a challenge in organic production, the growth and expansion of this system is dependent on sustained use of good quality organic seed. Due to the limited supply of organic seed, the National Organic Program (NOP) allows the use of untreated conventional seed in organic production of vegetables and other crops. Conventional seed derives from a high input production system using synthetic pesticides and fertilizers. They also offer many varieties and are readily available at a much lower price compared to organic seed. Organic systems demand cultivars with different characteristics often absent in conventional cultivars, and this need begins with the seed. It is not common practice for farmers to test or sanitize seed before planting. Consequently, the use of such conventional seeds, which may not be well adapted to the low input organic production system, could favor disease susceptibility, establishment of seedborne pathogens especially in vegetables and their subsequent dissemination in the organic production system. Our overall goal is to improve organic vegetable crop health and production in the southeastern U.S. through application of sustainable seed health management and help limit seed borne infections, transmission and dissemination in organic vegetable production fields.

Health identification of Shorea javanica Koord. and valeton in nursery

Shorea javanica Koord. and Valeton is an identity tree of Lampung Province. The dammar of this species, locally known as damar mata kucing (cat-eye resin). The population of S. javanica is mostly in Repong Damar and grows naturally in Bukit Barisan Selatan National Park. Within a decade, the damar mata kucing production was decreased. The threat of deforestation, land degradation, and the scarcity of regeneration were some of the causes. One of the important efforts that could be done was to procure quality seedlings in the nursery. Knowledge of the health condition of seedlings in a nursery is very important in supporting plant cultivation success. Plant insects and diseases were one of the determining factors. This study aims to determine the health of S. javanica seedlings in South Lampung Permanent Nursery, which Way Seputih Way Sekampung Watershed Management Center and Protected Forest manage. This seed health identification activity used the Systematic Random Sampling method with a sampling intensity of 10%. The samples obtained were carried out by identifying the type of damage, location of damage, and severity of all S. javanica seeds sampled using criteria and standards for crop assessment results according to the International Center’s Environmental Monitoring standards Assessment Program (EMAP). Based on the result of the research, from 100 seedlings of S. javanica that was observed 75% of seedlings are unhealth, and 25% of seedlings are healthy. Among the 75% unhealthy seedling, 2% were dead. The intensity of total attack is about 73%, the intensity of insect attack is about 41%, and disease attack intensity is 32%, with the highest attack severity 30-39%. The results showed that the live percentage of S. javanica seedlings was 98% which was in the very good category.

Longevity of Plant Pathogens in Dry Agricultural Seeds During 30 Years of Storage

Plant diseases may survive and be spread by infected seeds. In this study we monitored the longevity of 14 seed-borne pathogens in 9 crop species commonly grown in the Nordic countries, in addition to a sample of sclerotia of Sclerotinia sclerotiorum. The data from the first 30 years of a 100-year seed storage experiment located in a natural −3.5 °C environment (permafrost) in Svalbard, Norway, are presented. To date, the pathogens, tested by traditional seed health testing methods (freezing blotter, agar plates, growing on tests), have survived. Linear regression analyses showed that the seed infection percentages of Drechslera dictyoides in meadow fescue, Drechslera phlei in timothy, and Septoria nodorum in wheat were significantly reduced compared to the percentages at the start of the experiment (from 63% to 34%, from 70% to 65%, and from 15% to 1%, respectively), and that Phoma betae in beet had increased significantly (from 43% to 56%). No trends in the infection percentage were observed over the years in Drechslera spp. in barley (fluctuating between 30% and 64%) or in Alternaria brassicicola in cabbage (fluctuating between 82% and 99%), nor in pathogens with low seed infection percentages at the start of the experiment. A major part of the stored sclerotia was viable after 30 years. To avoid the spread of seed-borne diseases, it is recommended that gene banks implement routines that avoid the use of infected seeds.

Seed Health of Chickpea as Influenced by Different Packaging during Storage

A storage experiment was conducted to know the influence of cloth, gunny, high density polythene (HDPE), and vacuum packed bags on the seed health of chickpea for 18 months. To investigate, chickpea seeds were packed in all the bags and were kept in ambient conditions. During the storage period, there was a lot of fluctuation in moisture content of the seeds based on the relative humidity in cloth, gunny, and HDPE bags due to the pervious nature of packaging materials whereas, there was no moisture fluctuation in vacuum packed bags due to lower water vapor and oxygen transmission rate and higher thickness of polythene bag used for vacuum package. After 8 months of storage period, there was bruchids infestation to the seeds stored in cloth, gunny, and HDPE bags whereas, no bruchids infestation were seen to vacuum packed bag even after 18 months of storage but germination, root length, shoot length, seedling vigour index, seedling dry weight has reduced and mean germination time, electrical conductivity of seed leachates has increased due to seed aging. Hence, vacuum packaging technology can be effectively used for storage of chickpea seeds for longer period without any aid of chemicals.

Sustainable Wheat Production and Food Security of Domestic Wheat in Tajikistan: Implications of Seed Health and Protein Quality

Staple crop yield, quality and sustainable production are critical for domestic food security in developing countries. In Tajikistan, both seed-borne diseases and protein quality impair the yield and the quality of the major staple crop, wheat. Here, we used a detailed two-year survey of fields on 21 wheat-producing farms in Tajikistan, combined with lab analyses on seed health and protein quality, to investigate the presence of seed-borne diseases and bread-making quality in Tajik wheat. Seed samples were collected for the analysis of: (i) the presence of common bunt (Tilletia spp.) using the centrifuge wash test, (ii) the major pathogenic fungi on/in the seed using the agar plate test and (iii) the protein amount and size distribution using size-exclusion high-performance liquid chromatography (SE-HPLC). Field occurrence of common bunt and loose smut was generally low (3 farms in year one (14%) showed common bunt occurrence), but the presence of fungi was observed microscopically on most seed samples (on seeds from 19 out of 21 farms = 91%). Tilletia laevis was the dominant agent in common bunt (present in 19 farms compared to T. tritici present in 6 farms). Altogether, 18 different fungi were identified from seed samples by microscopy. Protein composition, measured with high-performance liquid chromatography as protein amount and size distribution (known to correlate with bread-making quality), differed significantly between samples from different farms and years, although the farm type and land elevation of the farm were not the determinants of the protein composition. The presence of certain fungi on the seed correlated significantly with the protein quality and could then have an impact on the bread-making quality of the Tajik wheat. The presence of seed-borne diseases, a low protein content and weak gluten were the characteristics of the majority of the grain samples, mostly irrespective of farm type and farmer’s knowledge. For sustainable development of the Tajik farming systems, and to strengthen the food security of the country, the knowledge of Tajik farmers needs to be increased independently of farm type; in general, plant breeding is required and certified seeds need to be made available throughout the country.