DROUGHT RESISTANT ALFALFA VARIETIES 

Many alfalfa producers ask,  

• "What variety resists drought?" and   

• "What variety will do the best without much rain?"   

The answer is always the same. The best alfalfa variety for good conditions (rain or irrigated) is the best under draughty conditions.   

Alfalfa is one of the most drought resistant crops. It has a vast root system which can get to moist soil, if it is there. When it does not find water, alfalfa goes dormant -- rather than trying to grow without enough water. Alfalfa can live during prolong droughts. When rains return, it will start growing again.   

This is not to say that alfalfa can produce high yields without large quantities of water. Alfalfa uses large amounts of water to produce high yields. It requires about 6" of water available to the root system to produce a ton per acre.   

Data summarized on the following page compare alfalfa yields at first harvest from several of our regular trials to yields in previous first-cuttings and yearly totals. The tables include yield and rank among the varieties shown for three tests at Stillwater, two tests at Perkins, and three tests at Chickasha. No irrigation was applied before first harvest this year.   

First harvest yields this year are much lower than normal (as expected). The column headings tell which year the test was sown; the year the data were collected, and which harvests are included. For example, 95-96-1 in each table indicates the test was sown in 1995, harvested in 1996, and only first cutting is shown. 93-95-Tot (in the top and bottom tables) says tests were sown in 1993, harvested in 1995 and the total yield for the year is presented.   

The most striking information is that the "good" varieties (as evaluated over many years) tend to have the highest yield during first cutting this year. As usual, there are some exceptions where a mediocre variety performed well this years first cutting.   

When choosing an alfalfa variety, pick the one that is best over the long haul, not just for one cutting. Stick with the best varieties for dry or wet years.   

Another thing these data show is the numerically highest yield may not really be better than some others in the test. The "LSD" (least significant difference) indicates how large the difference between two varieties must be before we are confident there is really a difference.   
      
 Results of Recent Alfalfa Variety Tests