Even though many farmers are still busy harvesting rice, now is the time to make a few preparations for the coming crawfish season. The vegetation growing in the pond over the next few months will greatly influence the food supply available for your crawfish for the whole season. Producing a forage crop does not guarantee that you will have crawfish. But if you do have crawfish, an adequate food supply will help them grow to more than just peeler size.
Most areas have had plenty of rain during July. So much so that fields have been too wet to adequately plow and prepare a seed bed for rice or sorghum-sudangrass. Many farmers have been asking about alternatives to planting or how late can they plant and still get enough growth before it’s time to flood up. The following scenarios and recommendations may help you decide what to do in your particular pond.
Monocropping Systems (Permanent Ponds)
Based on research conducted at the Rice Research Station in Crowley, rice is a good forage crop to have in a pond, particularly if it is green and growing during the fall when crawfish are emerging from their burrows with their babies. A thick stand of green rice offers protection from predators and promotes growth because of the good water quality. Rice planted in the first couple of weeks of August will be 15 to 20 inches tall by early October in time to flood up.
The best chances of getting a good stand of rice up will be to drill or broadcast seed into a plowed seed bed. If the dry weather this week holds out a little longer, you still may have time for the field to dry enough to plow and plant rice. If delays occur, you can plant sorghum-sudangrass until about the first of September.
Sorghum-sudangrass is a good, late-planted alternative to rice as long as you can give it about 4 to 6 weeks of growth before flood up. It will stop growing once you put the water on it. Ideally, it should be at least 3 to 4 feet tall when you flood.
A few farmers have held a shallow flood on the pond all summer to reduce the weed growth and so they can fly in some rice seed right now in early August. This seems to work well as long as a heavy rain does not fill the pond during the summer and flush the brood stock out of the burrows in the heat of the summer. The field should be drained after seeding to avoid scalding the seedlings.
When planting rice or sorghum-sudangrass, take into account the extreme heat of August and flush the field if necessary to prevent the seedlings from drying up. On the other hand, puddles of hot water will scald and kill young rice or sorghum-sudangrass, so a well drained field is important. Sorghum-sudangrass requires much less water than rice and can not tolerate standing water when young. Check frequently for armyworms and treat if necessary.
The least preferred food source is natural vegetation whether it is alligator weed, needle grass or a variety of grasses and sedges. Most of these plants will die and decay as soon as you flood up. This causes poor water quality that can kill young crawfish or stunt their growth. The lack of food later in the season will also cause stunting.
Rotational Systems (Rice Stubble)
Of course rice fields that will be flooded for crawfish in the fall should have been stocked last May or June. Assuming your brood stock is alive and well in their burrows, their survival and growth potential will depend on how you manage the rice stubble. Obviously, large piles of straw in the field will hinder stubble re-growth and cause terrible water quality problems for several months after flood up. As soon as the combines leave the field, turn on the pumps to put a light flood. This will stimulate the ratoon growth. If the straw is sitting in rows on top of the stubble, it can be burned as soon as there is enough water to cover the basal crown of the rice plant. The other alternatives are to bale the straw before flushing or else spread the straw and try to wet the biomass several times to begin the decaying process before its time to flood up.
General Observations
Crawfish continues to be an important crop for many farmers and landowners. Many farmers have increased their acreage over the years but have not increased their pumping capacity. Where they used to manage 40 acres with an eight inch water well, now they are trying to crawfish 80 or 100 acres with the same pumping capacity. In this case, you no longer have the ability to flush a pond that is having water quality problems. Too often the first waves of young crawfish die which reduces your total catch and delays your harvest until late spring.
Think about your pumping capacity (how fast you can deliver water to the field) as well as pumping efficiency (how much does it cost to fill and flush the pond). The type of forage and the amount of dead vegetation in the pond will influence how often and how much you need to pump. In light of higher fuel costs, it may be good to check the efficiency of pumps and motors and make changes as needed.
Additional useful information can be found in the recently updated Louisiana Crawfish Production Manual available at your parish Extension office. Pick up a free copy or view it on the LSU AgCenter’s web site at www.lsuagcenter.com
New Addition to the AgCenter’s Aquaculture Staff
The AgCenter recently hired Mr. Richard Johnson to assist in the aquaculture program in the Southwest Region. Richard will be working out of the Regional Extension Office at the Rice Station and can be reached at (337) 788-7547. Please welcome Richard as he joins Mark Shirley and Drs. Greg Lutz, Robert Romaire and Ray McClain in serving Louisiana’s crawfish industry.
Mark Shirley
SW Regional Aquaculture
337-898-4335
Dr Greg Lutz
Specialist State Aquaculture Specialist
225-765-2848
Richard Johnson
SW Regional Aquaculture Assistant Agent
337-788-7547