The rains over the past few weeks have been persistent across Louisiana. When it began raining about three to four weeks ago, only central and southern Louisiana were receiving rainfall. By late June, all portions of state had been affected.
Regarding the Louisiana corn crop, I am amazed by how it is standing up to the rains that continue to come down. There have been concerns over nitrogen losses and water stresses. Some of those issues will not be resolved until we harvest the crop.
I have been looking at producers’ fields all over the state and have seen some slight differences in ear development.
Where the crop has been severely stressed early by standing water, ears are generally shorter and have irregular kernel settings. In contrast, many fields, even after being wet for an extended period of time, still look very good.
Some fields in late June had very good yield potential. How much yield has been lost? That is the million dollar question. I do not think we will have much more than a 10 percent yield reduction in the overall state average (which fluctuates between 140 and 150 bushels per acre over irrigated and non-irrigated fields).
On irrigated fields, the loss can be “absorbed” because irrigation has not been used to make the crop. At least, that is one way to think about it.
The 2004 Louisiana grain sorghum crop is smaller than last year’s crop. Acreage for the state is an estimated 100,000 acres. I am noticing johnsongrass escapes where water has been standing and very uneven heading.
Overall, the grain sorghum crop is shorter in stature than what we like to see, but water stresses have inhibited growth potential. Fields that have had standing water are heading out unevenly by as much as over a week in some situations. That will stagger maturity over a field and complicate insecticide sprayings.
Our crop is spread out from V2 all the way to R6 on the earliest plantings. Rainfall has keep us from planting behind all our wheat acres. Kurt Guidry, an LSU AgCenter economist, said Louisiana wheat acreage was about 150,000 acres. Most of our wheat production is usually double-cropped with soybeans. How much was not planted to soybeans this year has yet to be determined.
The soybean crop is not growing at a record pace, but that it is not standing still is positive news. There has been little insect and disease pressure to this point, but we expect that to pick up very quickly.
Most of the insect activity has been from armyworms in southwest Louisiana. There have been isolated reports of stink bugs — primarily in the sugarcane belt. Some producers have been spraying for insects along tree lines and not spraying whole fields in an attempt to keep populations from building up.
The soybean crop over much of Louisiana has not lapped the middles, causing some fields to be weedier than others. Some producers have told me they will not spray more than three times, which considering the year will be the norm.
Some producers have had the opportunity to put out fungicides. The most popular treatment I’ve heard about is 4 ounces of Quadris and 0.5 pound active of Topsin-M. In central Louisiana I’ve see a number of fields beginning to show signs of Cercospora. To this point, I have seen very little aerial blight.
The soybean crop still has good potential in regard to yield. I have walked some fields that look excellent. They were mainly Group 4s planted on narrow rows on heavy soil during the first week of April. They have had excessive rainfall, but the fields are well-drained.
Some portions of the crop are struggling where fields are not as well-drained and have stayed under water. The soybeans are shorter in stature and will be difficult to harvest.
I rate the crop as 30 percent excellent to good, 60 percent good to fair and 10 percent poor. That could change as the season progresses.
With all of the rain this year, beans planted on rows or beds are generally doing better than beans which have been planted flat. The raised beds have saved a great deal of acres from being replanted.
The weather will improve. When it does, we need to spray most of the fields with a pesticide as quickly as possible.
David Y. Lanclos is the soybean, corn and grain sorghum specialist at LSU AgCenter. e-mail: [email protected]