Abstract
Silflower (Silphium integrifolium Michx.) is in the early stages of domestication as a perennial version of oilseed sunflower, its close relative. Grain crops with deep perennial root systems will provide farmers with new alternatives for managing soil moisture and limiting or remediating soil erosion, fertilizer leaching, and loss of soil biota. Several cycles of selection for increased seed production potential following initial germplasm evaluation in 2002 have provided opportunities to document the botany and ecology of this relatively obscure species, to compare agronomic practices for improving its propagation and management, and to evaluate the differences between semi-domesticated and wild accessions that have accrued over this time through intentional and unintentional genetic processes. Key findings include: domestication has increased aboveground biomass at seedling and adult stages; seed yield has increased more, achieving modest improvement in harvest index. Harvest index decreases with nitrogen fertilization. Silflower acquires nitrogen and water from greater depth than typical crops. In agricultural silflower stands within its native range, we found that Puccinia silphii (rust) and Eucosma giganteana (moth) populations build up to unacceptable levels, but we also found genetic variation for traits contributing to resistance or tolerance. Breeding or management for reduced height and vegetative plasticity should be top priorities for future silflower research outside its native range.
Highlights
Investment in the development of perennial grains as future substitutes for similar annual grains has largely been justified by the expectation that the longer growing season, permanent root system and reduced frequency of tillage will slow or even reverse the loss and degradation of agricultural soils, use available resources more efficiently, and produce greater returns on investment of fuel and fertility [1,2,3]
While goals for improving standard domestication traits relating to seed production, harvesting, and processing are clear, defining a whole plant breeding/domestication ideotype for silflower must take into account the target regions and production systems
Developing management and/or genetic solutions to serious insect and pest problems, like breeding for non-shattering seeds, is standard procedure in crop breeding and domestication. For new crops such as silflower, little was known about which pests would be severe within production plantations
Summary
Investment in the development of perennial grains as future substitutes for similar annual grains has largely been justified by the expectation that the longer growing season, permanent root system and reduced frequency of tillage will slow or even reverse the loss and degradation of agricultural soils, use available resources more efficiently, and produce greater returns on investment of fuel and fertility [1,2,3]. Perennials are being sought as substitutes for annual bioenergy crops [4]. Perennials with coarse taproots may have additional advantages over other kinds of crops. They can use water stored deep in the soil thereby avoiding water stress during short-term droughts in rain-fed agriculture. The perennial crop is said to provide a “root safety net” in this case [5,6]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
