The real key to this type of herbicide program is the post-emerge herbicide you choose, because the idea here is to spend just a few dollars on a pre-emerge herbicide to hold weeds down for a while, and then clean up grasses AND broadleaves post-emerge.

The trouble with this program is that the post-emerge herbicide you pick may limit your choices in terms of hybrid selection. For example, if you decide to pick Roundup as your post product, you are limited to Roundup Ready corn. If Liberty is your choice then Liberty Link hybrids are the only ones you can plant, and if Lightning is your pick, then you must plant Clearfield corn.

Well, before we get more into the specifics on which herbicides to use, let's talk about why you might want to consider a herbicide program like this on your farm.

Traditionally, there have been 2 basic programs for weed control in corn on a farm. Conventional and total post. The conventional herbicide programs, that we talked about last week, consist of applying a pre-emerge herbicide in the spring to control ALL of your grasses and some of your broadleaves. Since it is extremely rare in the western cornbelt to find a herbicide to apply pre-emerge that will kill everything, this program has been used successfully on the majority of acres for many years. However, in no-till and when problem grasses like woolly cupgrass, field sandbur, and wild proso millet are present, this program is not very effective.

With the total post program, a farmer can have some success if the weeds are small, if the weed pressure is light, if the weather is just right, if the spray solution is mixed correctly, and if God is smiling on you that particular day. In other words, there are way too many "ifs" to count on a total post program on all your acres every year. Sooner or later, you will have a disaster that will cost you thousands of dollars. Even in a total Roundup program on Roundup Ready corn, yields can be lost so easily if spraying is not done at exactly the right time and weeds are allowed to compete with your crop.

Because neither the conventional program or the total post program is consistently effective on most farms in no-till or when problem grasses are present, many farmers are turning to the light pre full post program in corn. The idea is to use a light rate of a pre-emerge herbicide, followed by the full rate of a post-emerge herbicide later on to clean up everything that's left.

As we said earlier, the key to this program is the post-emerge herbicide you use. On the transgenic side, you can choose Roundup or Liberty. You can also pick Lightning if you have Clearfield corn. If you have conventional corn, you can either take a premix like Accent Gold or Celebrity Plus, or mix your own grass and broadleaf killers. If you mix your own, the best grass product is Accent, and the products you can mix with it include Callisto, Hornet, Buctril, and Clarity. If you do have problem grasses like woolly cupgrass, sandbur, or wild proso, you will probably be happiest with Roundup, but Liberty is quite effective, too, if you use the 32 oz rate.

Regardless of the post product you pick, you will spend quite a few dollars per acre. Sure Roundup isn't that expensive, but don't forget about the extra cost of Roundup Ready corn. The good news this year is that Liberty is dramatically cheaper than it used to be, and Roundup and Lightning are at all-time low prices, too. Therefore, it will be less expensive for you to run with this type of program in 2003 compared to 2002.

Now let's turn to the pre herbicides for a minute. The premise here is to use a reduced rate of a pre-emerge product to hold back the weeds until you can spray your post-emerge herbicide. Our best suggestion is a 1 oz rate of BalancePro in states where it's labeled. We like Balance because it has some activity on most grasses and broadleaves, and it's cheap. The 1 oz rate should cost you less than $6 an acre.

If you don't use Balance, we suggest a cut rate of Harness or Surpass. These herbicides are the next best choices on tough broadleaves like waterhemp and lambsquarters, and we all know how effective these herbicides are on grasses. Again, though, use a reduced rate. If you spend no more than $5 to $8 an acre here, you will get a great return on the investment, and you will have plenty of money left to spend on a good post-emerge product.

If you do decide to use the light pre full post program in your corn this year, there are a couple of things we will caution you on. First of all, be sure to pick the right corn hybrid. It has happened to many farmers
before where they buy Liberty Link corn and spray Lightning over the top. Liberty corn will die if Lightning is sprayed over the top, just like Clearfield corn will die if you spray Liberty over the top, so don't get confused.

Next, keep in mind that if you use a reduced rate of a pre-emerge herbicide, you should not expect 100% control from this. The idea behind this program is to suppress the early season weeds and then kill everything with the post-emerge herbicide. Now, the only time we feel you need to run with the FULL rate of a pre AND spray the FULL rate of a post grass and broadleaf herbicide, is if you have VERY heavy weed pressure. Then, by all means, spend the extra money, or the weeds may get too far ahead of you before you can kill them post-emerge.

Finally, spray your post product late. If you spend the $5 to $8 an acre on a reduced rate of a pre-emerge herbicide, you should have plenty of time to get your spraying done. However, if you spray your post-emerge herbicide when your corn is only 4 inches tall, you very easily could have weeds popping up BEFORE your crop has a chance to canopy. Depending on the herbicide you use, we normally recommend waiting until your corn is 8 to 12 inches tall before spraying your post-emerge chemical in this program.

In review, the light pre full post program works well in no-till or if you have problem grasses on your farm.

In the light pre full post program, you will apply a reduced rate of a pre-emerge herbicide to hold back the grasses and broadleaves and maintain your yield potential until you can spray post-emerge.

When you do spray post, be sure to use a product that kills both grasses and broadleaves if you are using this type of program.

If done right, this program will cost no more than a conventional herbicide program, and it will provide better weed control and higher yields in the situations we talked about today.