Improving seed germination of the eggplant rootstock Solanum torvum by testing multiple factors using an orthogonal array design

[EN] Solanum torvum is a highly vigorous relative of eggplant that is resistant to a number of harmful soil-borne diseases and is compatible for grafting with eggplant. Being a potential rootstock, this plant frequently presents poor and erratic germination, which makes its practical use difficult. We used an L8 (2(7)) orthogonal array design to evaluate the primary effects of seven factors (soaking of seeds, scarification with sodium hypochlorite (NaClO), application of gibberellic acid (GA(3)), use of potassium mitrate (KNO3) as a moistening agent, cold stratification, application of a heatshock, and light irradiation during germination) at two levels (L0 and L1) using four germination parameters (early and final germination, germination rate and vigour index) in fresh S. torvum seeds. S. torvum seeds had a strong dormancy with no germination in the untreated seeds and high early and final germination (approximately 100%) in certain treatments. An evaluation of the main effects revealed highly positive effects on germination from seed soaking, and the use of GA(3), KNO3, and light irradiation, whereas NaClO scarification had a negative effect. The application of cold stratification and heat shock treatments also had a positive effect on seed germination but to a lesser extent than the other treatments. An improved proposed protocol that consisted of subjecting seeds to soaking, the application of GA(3) and KNO3, cold stratification, heat shock, and light irradiation was validated and demonstrated to be highly effective, with seed germination success greater than 60% being observed at 3 days and final germination reaching a plateau at 6 days. A second validation experiment using a commercial growing substrate also showed a high emergence (approximately 50%) at 7 days and a final germination of approximately 80% was recorded with application of the improved protocol. The seed germination protocol that we have developed will facilitate the use of S. torvum as a rootstock for eggplant and its use in breeding programmes. Our results also reveal that orthogonal array designs are a powerful tool for establishing improved protocols for seed germination. (C) 2015 Elsevier B.V. All rights reserved.This work was completed as part of the initiative "Adapting Agriculture to Climate Change: Collecting, Protecting and Preparing Crop Wild Relatives", which is supported by the Government of Norway. The project is managed by the Global Crop Diversity Trust with the Millennium Seed Bank of the Royal Botanic Gardens, Kew and is implemented in partnership with national and international gene banks and plant breeding institutes. For further information see the project website: http://www.cwrdiversity.org/. Isabel Andujar and Pietro Gramazio are grateful to Universitat Politecnica de Valencia for their post-doctoral (PAID-10-14) and pre-doctoral (Programa FPI de la UPV-Subprograma 1) contracts, respectively.Ranil, RH.; Niran, HML.; Plazas Ávila, MDLO.; Fonseka, R.; Hemal Fonseka, H.; Vilanova Navarro, S.; Andújar Pérez, I.... (2015). Improving seed germination of the eggplant rootstock Solanum torvum by testing multiple factors using an orthogonal array design. Scientia Horticulturae. 193:174-181. https://doi.org/10.1016/j.scienta.2015.07.030S17418119

Forage Yield and Silage Quality of Dual-Purpose Corn Hybrids in Two Levels of Urea Fertigation

The experiment was completed to evaluate the responses of forage yield and silage quality of dual-purpose corn hybrids to urea fertigation. For this purpose, two studies were conducted each as a split plot experiment based on a randomized complete block design with three replications at two locations in research farms of College of Agriculture, Isfahan University of Technology, Isfahan, Iran, in 2016.  Two levels of nitrogen fertigation including 150 and 200 kg ha-1 in Lavark Research Field -Najafabad city; 200 and 250 kg ha-1 in Shervedan Research Field- Flavarjan city with urea fertilizer, N= 45%, and 20 forage-grain corn hybrids were designed as main and sub plots, respectively. The results showed that the increased application of nitrogen fertilizer improved biological yield in Shervedan field and dry matter percentage and silage yield in both locations, but had no effect on the ratio of forage components including leaves, stems and ears to total forage weight. The protein concentrations of silage hybrids increased significantly as a result of increasing nitrogen application in Shervedan. Also, with increasing nitrogen fertilizer, the amount of ash in both locations increased, but insoluble fibers in neutral detergent and insoluble fibers in acidic detergent decreased. The interaction effects of nitrogen × hybrid on silage acidity was significant in Shervedan. At Shervedan field, the highest biological yield (298,000 kg/ha) and silage dry matter percentage (29.8%) were observed in AGN591 and Whichita with application of 250 kg/ha N-fertilizer. AGN756 had the highest biological yield (27,200 kg/ha) and silage dry matter percentage (28.6%) upon application of 200 kg/ha N-fertilizer in Lavark field station. It seems that in each region, by using the appropriate amount of nitrogen fertilizer and selecting high-potential yield hybrids, both acceptable quantitative and qualitative yields of corn silage can be achieved

Comparing the emergence of Echinochloa crus-galli populations in different locations. Part I: variations in emergence timing and behaviour of two populations

Echinochloa crus-galli (L.) P.Beauv. is one of the most important weeds; it is distributed worldwide and has adapted to diverse habitats and climatic conditions. This study aimed to compare the emergence patterns of two populations of E. crus-galli from different environments at 11 locations across Europe and the Middle East. Seeds of the two populations were collected from maize in Italy and from spring barley in Norway and were then buried in soil in autumn 2015. In the spring of 2016, the soil was disturbed around the usual seedbed preparation date in each location and emergence recorded. The soil was again disturbed a year later and emergence was recorded for a second season. Total emergence, the times of onset, end and to 50% emergence and the period between 25% and 75% of emergence were analysed by two-way ANOVA and Principal Components Analysis (PCA). The Italian population showed a higher emergence than the Norwegian population in Southern locations, while the ranking was reversed in Northern locations. In almost all locations, a tendency to emerge earlier was recorded for the Norwegian population, but the periods from 25% to 75% emergence were similar for both populations. Total emergence, and the times of onset and end of emergence seemed to be mainly under genotypic (plus maternal) control, suggesting there were different temperature thresholds for seedling emergence in each population. Conversely, the duration of emergence seemed to be mainly under environmental control. This research confirms the high variability between populations and suggests the need to continue identifying key characteristics for the development of efficient models for seedling emergence in specific climates and/or latitudes