In a 3 year herbicide-crop rotation involving corn (Zea maysL. ‘Coker 811A’), cotton (Gossypium hirsutumL. ‘Carolina Queen’), and peanuts (Arachis hypogaeaL. ‘Argentine’), uncontrolled yellow nutsedge (Cyperus esculentusL.) and annual weeds drastically reduced all crop yields. By the end of the rotation sequences, intensive cultivation throughout the rotation killed 97 to 99% of the nutsedge tubers, but this level of control depended on hand-weeding the cotton. Moderate application of herbicides killed from 78 to over 99% of the yellow nutsedge tubers, while intensive treatment with herbicides produced at least 99% kill. In addition, all annual weeds present when the experiment was initiated were controlled satisfactorily by intensive herbicide applications except Florida beggarweed [Desmodium tortuosum(Sw.) DC.] in peanuts. The major change in composition of the weed population was a reduction in yellow nutsedge and in the total number of weeds; however, certain other population shifts also seemed affected by the weed control treatments. Compared to intensive cultivation, the investment in intensive herbicide treatment produced maximum yields and highest gross profit per acre. None of the treatments affected the market grade or organoleptic characteristics of peanuts. The fatty acid content of corn and cotton changed significantly only in 1967.

Nine corn hybrids were grown at 5 locations in 1962 and at 6 locations in 1963 to study the factors which may influence the oil content and quality of the corn kernel. Three dates of planting were used at one location in each year. First and second ears were harvested separately and analyzed for oil content by nuclear magnetic resonance and for fatty acid composition of the oil by gas‐liquid chromatography. Oil content and quality were not greatly affected by different dates of planting. Ear position had no effect on palmitic, stearic, and linolenic acids. Although not always significant, the oil from the first ear was always higher in oleic acid and lower in linoleic acid than the second ear. The seeoml ear was lower than the first ear in oil content in 1963 but not in 1962. Year, location, and hybrid effects were highly significant for all characters. First and second order interactions were generally nonsignificant. Hybrids had a greater influence on the characters studied than any of the environmental factors.

Five chromatograms of the fatty acid composition of oil of 2 kernels from each of 8 entries were used in comparing 3 gas‐liquid chromatographic procedures. Procedures 1 and 2 had a column temperature of 235 C and recorder chart speed of 2 and 3 inches per minute, respectively. Procedure 3 had a column temperature of 200 C and chart speed of 1 inch per minute. Differences in entries, procedures, and kernels in entries were highly significant. However, variance components estimates showed that procedures and kernels in entries contributed little to the total variance. Standard errors and coefficients of variation were similar for all procedures. Accurate fatty acid analyses were obtained in less than 3 minutes by procedures 1 and 2.

Manganese deficiency is known to severely reduce growth and yield of soybean [Glycine max (L.) Merr.] plants, but little is known about the effects of Mn deficiency on soybean seed quality factors. Seed from field‐grown soybean plants containing leaf Mn concentrations ranging from 4 to 58 ppm were analyzed for oil and protein percentage. Seed oil and seed protein from selected treatments containing 4 to 44 ppm leaf Mn were analyzed for fatty acid and amino acid percentages, respectively.Severe Mn deficiency (less than 15 ppm Mn in the leaves) increased seed protein percentage and decreased seed oil percentage. Seed from plants with extremely low leaf Mn levels contained higher percentages of linoleic, palmitic, linolenic, and stearic acids and a lower percentage of oleic acid. The percentages of seed protein, seed oil, and fatty acids changed markedly at low leaf Mn levels but remained relatively constant above leaf Mn concentrations of 15 to 20 ppm. Percentages of amino acids in seed protein were relatively unaffected by Mn.The results show that several soybean seed quality factors can be markedly altered by deficient levels of Mn. These changes could have a significant influence on the quality of products derived from soybean seed.

This study was conducted to determine the effect of nitrogen and boron on protein and oil percentages and fatty acid composition of corn (Zea mays L.) grain. In one study, two rates (90 and 180 kg/ha) of nitrogen, two periods (December and preplant), with and without a nitrification inhibitor were applied to corn on a Norfolk loamy sand soil in the Coastal Plain region of Georgia. In a second study, three rates (0.28, 0.56, and 1.12 kg/ha) of boron were applied to the same soil as for study one. Check plots with no treatment were included in each experiment. Grain samples from each plot were analyzed for protein and oil percent by standard A.O.A.C. methods and the fatty acid composition of oil was determined by gas‐liquid chromatography. Protein percent increased with increasing rates of N without any effects from time of application or of the nitrification inhibitor. Nitrogen had no effect on oil percent or oil composition. Boron fertilization had no effect on any of the chemical characters measured in this study.

Planting date studies were conducted on sunflowers (Helianthus annuus L.) from 1969 through 1971 at Experiment, Ga. to evaluate the optimum time of planting on seed yield, oil percentage, oil composition, and other plant characteristics. Seeds of ‘Peredovik’ and ‘Krasnodarets’ varieties were planted at each date ranging from March 11 to July, 22. Highest seed yields and oil percentage of seeds were produced when sunflowers were planted from mid‐March through April. Fatty acid composition of seed oil varied considerably among planting dates within years as well as among similar planting dates between years. Other sunflower characteristics were not greatly affected except at the June or July plantings.

No abstract

Systems of weed control composed of (a) intensive cultivation only, (b) herbicides only, or (c) herbicides plus cultivation controlled weeds in soybeans(Glycine max(L.) Merr.) with acceptable crop tolerance. On Ocilla sandy loam, systems withS-propyl dipropylthiocarbamate (vernolate) as a preplanting treatment and 3[p-(p-chlorophenoxy)phenyl]-1,1-dimethylurea (chloroxuron) as an early postemergence treatment, followed by either sweep cultivations or directed postemergence applications of other herbicides, controlled yellow nutsedge(Cyperus esculentusL.) satisfactorily and controlled 99 to 100% of the common cocklebur(Xanthium pensylvanicumWallr.) and Florida beggarweed [Desmodium tortuosum(Sw.) DC.]. As directed postemergence treatment, 2-seobutyl-4,6-dinitrophenol (dinoseb) controlled common cocklebur and Florida beggarweed about as well as 3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea (linuron). However, for the broad spectrum of weeds encountered on the Greenville soil, linuron was superior to dinoseb, especially on Texas panicum(Panicum texanumBuckl.). Systems containing only cultivation controlled 84 to 98% of the common cocklebur and 78 to 99% of the Florida beggarweed. On Greenville sandy clay loam, several systems of weed control significantly reduced the stand but not the yield of soybeans. Vernolate reduced stands when used as a preplanting incorporated treatment but not when injected at planting. No significant yield differences among the weed control systems were apparent in the 3-year averages. Costs of weed control ranged from $20 to $30/ha for cultivation only, from $55 to $73/ha for herbicides only, and from $45 to $53/ha for herbicides combined with cultivation. Uncontrolled weeds, primarily common cocklebur and Florida beggarweed, in the weedy check plots reduced the average yield of soybeans 74% on the Ocilla soil during the 3-year period. The different systems of weed control did not affect commercial quality of soybean oil.