STANDFASTTM ALFALFAS DELIVER IMPROVED STANDABILITY AND UP TO 30% FASTER RECOVERY AFTER HARVEST

 

David Johnson, Mark Darling, Doug Miller, and Jonathan Reich

Cal/West Seeds, West Salem, WI

 

The improvement of forage yield, forage quality, and stand persistence have been primary objectives to alfalfa breeders and farmers alike.  The quest for improvements in these important traits has lead Cal/West Seeds, one of the world's top forage breeding firms, to develop a unique family of tall, fast-growing alfalfas with improved standability and faster recovery after harvest.  StandFastTM alfalfas offer high yield, quality, persistence, a complete pest resistance package, improved standability, and faster recovery after harvest.

 

Alfalfa (Medicago sativa L.) is an important forage species for hay and pasture.  It has been referred to as the “Queen of the Forages” because of its high forage yields and feeding value.  Alfalfa is recognized as the most widely adapted agronomic crop and although alfalfa originated in southwestern Asia, it is well adapted to a wide range of climates and soils throughout the world.  Alfalfa is classified into fall dormancy groups, numbered 1 to 10 that fit into the USDA plant hardiness zone map.  Dormancy group 1 is the most dormant alfalfa and is adapted to cold, temperate climates (such varieties stop growing and go dormant over winter).  Dormancy group 10 alfalfa is very non-dormant and suited for warm, equatorial type climates (such varieties have high growth rates over a very long growing season and relatively high winter activity).

 

Commercial alfalfa seed may be provided either in a synthetic variety or a hybrid variety.  Commercial production of synthetic varieties may include a breeder seed production stage, a foundation seed production stage, a registered seed production stage and a certified seed production stage.  Hybrid variety seed production may involve up to three stages including a breeder seed production, a foundation seed production and a certified seed production.

 

Efforts in developing healthy and productive alfalfa varieties often focused on breeding for disease and stress‑resistant cultivars; i.e. breeding for persistence, adaptation to specific environments, yield, and quality.  Between 1900 and 1975 more than 160 cultivars were developed for production in North America.  Most new cultivars were selected for improved adaptation and multiple pest resistance.  Success has been attained in breeding for resistance to fungal, bacterial, insect, and nematode pests.

 

Breeders have had less success in breeding for yield and quality per se, although methods have been developed that help increase yield and productivity.  Many factors affect the yield, productivity and quality of alfalfa harvests.  One of the many factors affecting the quality of an alfalfa harvest is the stage of development or physiological maturity of the plant at harvest time.  This dependency on stage of development suggests that the maturity level of the alfalfa can predict herbage quality.  And, in fact, methods of classifying the morphological stage of alfalfa have been developed to assist in the prediction of herbage quality.

 

            Another factor that affects yield and quality is plant lodging that can result in plant stubble being left in the field at harvest time.  Lodged or downed alfalfa causes great losses to farmers because it increases mowing time and results in reductions of both the yield and the quality of the harvested crop.  University research has shown that an unharvested seven-inch stubble versus a clean-cut 2-inch stubble can reduce forage yield by up to one third.  Thus, alfalfa plants with improved standability require less mowing time and have a higher forage yield with improved forage quality.

 

            Recovery time between harvests also limits overall alfalfa yields.  Faster recovery between harvest shortens the number of days between harvests, which therefore maximizes the number of harvests and net yield for each season.  Growers recognize and value the importance of this characteristic for its contribution to the season’s net yield per acre.  Additionally, fast recovery also contributes to moisture conservation, weed control and forage quality.

 

As demonstrated by this review, there is a real need for alfalfa varieties with improved standability and faster recovery after harvest.  StandFast technology traits provide alfalfa plants with improved standability and faster recovery after harvest.  StandFast alfalfa plants will reduce field losses from downed alfalfa, and provide for a better season long-distribution of yield, faster ground cover after harvest, flexible harvest window, more net yield each season, equipment and labor efficiencies and management flexibility.

 

 Standability refers to a plant’s resistance to lodge.  The standability rating is based on the percentage of stems that are standing upright at 50% flowering or late bloom.  The improved standability helps reduce field loss and the faster recovery after harvest contributes to maximum net yield each season.

 

Prior to StandFast alfalfas, the standability differences between commercial alfalfa varieties in the US has been so small that most alfalfa breeders do not even rate their varieties for this important trait.  The improved standability of alfalfa with StandFast technology traits are even more useful when weather conditions persist that would cause currently available alfalfa varieties to lodge.  The faster recovery after harvest of the StandFast alfalfas speed “green-up” by 3-5 days, which reduces the number of days to maturity and to the next cutting.  This earlier maturity to harvest starts with the first crop and can give large acreage alfalfa growers or dairymen who use contract harvesters a head start each season.  The days gained on each crop harvest helps maximize the number of cuts taken before the fall cut-off date for harvesting.  Thus, the improved StandFast alfalfas allow growers to put up more of the season’s total yield at mid-summer when weather is usually more cooperative.

 

Most alfalfas are described as having fast recovery since the characteristic is generally correlated with high yield.   With StandFast technology traits, recovery after harvest refers to the rate of regrowth after harvest.  This is determined scientifically by measuring plant height at varying intervals and then comparing growth with check varieties.

 

 The alfalfas with the StandFast traits recover 10-30% faster than presently available dormant alfalfas, including hybrids.  This measured faster recovery can add up to an extra 6-inches of growth during the first 21 days after harvest.  The result is a crop that's ready for harvest 3-5 days ahead of today's fastest growing commercial alfalfas which translates to more net yield each season.

 

StandFast alfalfa varieties were developed from crossing European germplasm screened for US adaptability onto elite US fall dormant plants selected for superior yield and productivity, forage quality and persistence.

 

StandFast alfalfas are high yielding.  StandFast alfalfas are bred for aggressive harvest systems and carry a multiple pest package and winter survival scores, which contribute to a significant, yield advantage during the later hay years.  Stand persistence after 3 years in replicated trials is Iowa, Minnesota, and Wisconsin exceeds currently available dormant alfalfa varieties.

 

Stem size and cell wall digestibility of the StandFast alfalfas is similar to today's top selling alfalfas.   When forage quality is measured as pounds of milk per ton of fed forage, StandFast alfalfas meet or exceed the industry forage quality check in side-by-side tests.   At the bud stage, these alfalfa plants will be tall with an upright growth habit and feature a dense, leafy and uniform canopy with medium-dark green plant color.  StandFast alfalfas are presently available in fall dormancy 4 and 5 types.          

 

Alfalfas carrying the improved standability and faster recovery performance traits will be identified as StandFastTM alfalfas in the marketplace.  The alfalfas carrying the StandFast technology traits will be available nationally for seeding during spring 2003.  Growers should contact their local seed dealers for more information and product availability.