Linda Benedict, Morgan, Johnny W. | 5/30/2012 8:01:13 PM
The soybean has not only been responsible for improving Louisiana farmers’ profit margin as a crop but has also been instrumental in improving soils for the production of other crops.
John Mitchell Jenkins, who was superintendent of the Rice Experiment Station – now the Rice Research Station – from 1917 to 1946, concluded that growing soybeans in rotation with rice improves the lands of southwestern Louisiana and increases the productivity and quality of rice.
Before 1957, approximately half of Louisiana’s soybean acreage was grown for crushing for its oil content. LSU AgCenter agronomy professor John Gray’s release of the Pelican soybean variety was the beginning of varieties good for forage and for crushing. One of the most outstanding strains of the Pelican 2x Ogden parentage was named the Bienville. It was released for 1958 planting. This variety averaged 40 bushels of seed per acre, which is only three bushels less than the state average for 2010.
Soybean acreage in Louisiana increased more than fourfold after 1960. Acreage planted in 1960 amounted to 216,000 acres, compared with estimated plantings of more than 900,000 acres in 1966. By the mid 1970s, acreage topped 3 million.
As the production of soybeans increased so did the yield-limiting problems of pests and soil fertility. From the record highs in the 1970s, soybean acreage dropped to a low of 640,000 acres in 2001.
Weed scientists have played a critical role in production success of soybeans in Louisiana. Now, the concern is how to effectively deal with herbicide-resistant weeds in soybeans. Research has shown that an extensive and effective post-emergence weed control program is essential for soybean production on most Louisiana farms. When planning a soybean weed management program either in the absence or presence of herbicide- resistant weeds, it is imperative that multiple herbicides with different modes of action be used. Research shows that applying a combination of soilresidual herbicides at planting followed by a timely post-emergent application of glyphosate along with other herbicides can provide season-long weed control.
Corn is the most widely grown feed grain in Louisiana. It is believed that corn became a cultivated crop in Louisiana when the Spanish provided seed to the early Acadian immigrants, who became ranchers on the prairie lands of southwest Louisiana.
With a need to provide feed for their cattle, farmers needed better ways to grow corn. An intensive corn breeding project was carried on by the Louisiana Agricultural Experiment Station during the early to mid-20th century.
In 1962, scientists at the Red River Research Station conducted a fertilizer rate and plant population study to determine the optimum fertilizer rate and plant population for maximum yields, the degree of response from the use of phosphorus and potassium, and the effect of the treatment on lodging. Corn yields increased in two of five years from plots receiving phosphorus. The response to potassium was erratic, and there were no significant effects on the degree of lodging from either inputs of fertilizer or plant population.
From 1992-2001, agronomist Rick Mascagni worked in corn hybrid performance testing and recommended varieties to growers.
Beginning in 2003, plant breeder Steve Moore, now retired, conducted experiments on 1,600 corn lines in his quest to reduce aflatoxin, a deadly toxin that develops in heat- and droughtstressed corn. Working at the Dean Lee Research Station near Alexandria, Moore said this toxin is the most potent natural carcinogen found in nature.
Ken Damann, plant pathologist, and others are focusing on three different technologies to reduce aflatoxin contamination in corn – breeding programs to develop resistant lines, chemical control and genetic control.
Wheat and Oats
There was a span of 58 years between the release of the Camellia oat variety in 1940 and the next Louisiana small grain variety release, the Secretariat LA495 oat, in 1998. Most of the wheat and oat research conducted in the Louisiana Agricultural Experiment Station between 1940 and 1985 focused on statewide variety trials and cultural and production practices for wheat.
Agronomist Ken Tipton’s statewide oat variety research in 1967-69 showed that no real difference in grain yield was found from north to south Louisiana.
Grain Sorghum (Milo) and Millet
In the late 1980s, Dan F. Clower conducted research with grain sorghum and found that as production increased, certain species of insects attacked this crop. He studied these pests to develop practical and economical control measures.
Millet and sorghum are still somewhat smaller acreage crops but still have a place in Louisiana agricultural production. In the 1950s, H. DeWitt Ellzey and T.E. Davis studied green feeding pearl millet to dairy cows in three grazing systems – rotation-grazed, strip-grazed and green-fed or zero-grazed. Their findings showed that from a practical standpoint, rotation grazing was the best of the three methods.
From 1978-80, H.P. Viator and J.G. Marshall compared yields in a doublecropping system of wheat and sorghum. They looked at differences between no-till and conventional till, burned stubble and nonburned stubble and 20- and 40-inch row spacing. They found that conventional tillage yields were higher during years of adequate rainfall, but no-till yields were much higher in the dry year of 1980. They also found that burning wheat stubble resulted in higher weed populations. And finally, rows 20 inches wide had higher yields and more effective weed control because of shading.
Johnny Morgan, Communications Specialist, Communications, LSU AgCenter, Baton Rouge La
(This article was published in the spring 2012 issue of Louisiana Agriculture.)