Agronomy Journal

Mathers, Aubra C.

doi: 10.2134/agronj1970.00021962006200050001xpmid: N/A

Sulfuric acid and ferrous sulfate treatnients of calcareous soil increased yields of hybrid grain sorghum grown in the greenhouse. Effects of 250 ppm or more Fe with 250 ppm or more H2SO4 were still significant on the third crop after soil treatments were made. This study shows that residual effects are possible from heavy applications of FeSO4and H2SO4.

Polson, D. E.; Adams, M. W.

doi: 10.2134/agronj1970.00021962006200050002xpmid: N/A

Saginaw and Sanilac navy beans (Phaseolus vulgaris) were grown at various combinations of high and normal levels of Zn, Cu, Fe, and Mn in sand culture. Saginaw variety grew normally at 5.0 ppm Zn, while the growth of Sanilac was extremely reduced. This difference was manifested in plant height, leaf number, and root and shoot weight. In addition, a differential Fe‐Cu interaction induced by high Cu levels was observed.

Adriano, D. C.; Murphy, L. S.

doi: 10.2134/agronj1970.00021962006200050003xpmid: N/A

Irrigated corn (Zea mays L.) grown on Zn‐deficient, slightly acid Cass fine sandy loam suffered from increasingly severe Zn deficiency when 40 kg/ha P (80 lb/A P2O5) was applied in a band to the side and below the seed. Zinc deficiency was corrected in the presence of the banded P when Zn was supplied at the rate of 11.2 kg Zn/ha as ZnSO4.

Power, J. F.; Grunes, D. L.; Reichman, G. A.; Willis, W. O.

doi: 10.2134/agronj1970.00021962006200050004xpmid: N/A

Results from this experiment indicate that for barley plants harvested at equal stages of morphological development, low soil temperatures per se are not deterimental to growth. Barley was grown to maturity in a growth room at soil temperatures of 9, 15.5, and 22C with either 9 or 44 ppm fertilizer phosphorus. At a given stage of plant development, dry matter production and N and P uptake were usually lowest at a soil temperature of 22C. Dry weights, grain yields, and nutrient uptake at 9C usually equalled or exceeded those at 15.5C — the soil temperature considered optimum for barely production. At 9C growth was very slow until the barley developed to the 4‐leaf stage, but thereafter approximated the growth rate at higher soil temperatures. Nutrient uptake and water use data suggest that the slow initial growth rate at 9C may be due to restricted nutrient translocation from roots to tops, rather than to reduced rate of uptake of water or nutrients. Soil temperatures affected both the growth rate and water use rate, resulting in only a small effect of soil temperature on total water used to reach a given growth stage.

Matocha, J. E.; Conrad, B. E.; Reyes, L.; Thomas, G. W.

doi: 10.2134/agronj1970.00021962006200050005xpmid: N/A

Yield response to applied phosphorus by grain sorghum (Sorghum bicolor L. Moench) was studied for 3 years on a Clareville clay loam, a dark, montmorillonite, calcareous soil typical of the Coastal Bend area in Texas.

Hackerott, H. L.; Harvey, T. L.

doi: 10.2134/agronj1970.00021962006200050006xpmid: N/A

Pearl millet, Pennisetum typhoides (Burn.) Stapf and C. E. Hubb.; foxtail millet, Setaria italica L.; and proso millet, Panicum miliaceum L. were evaluated for resistance to the C‐biotype greenbug, Schizaphis graminum (Rondani), a recent serious pest of sorghum, Sorghum bicolor (L.) Moench. All trials were conducted in growth chambers at 27 C. Survival and reproduction of adult greenbugs confined to seedling and mature plants were greater on sorghum than on the millet species. The millets were also more resistant than sorghum on the basis of plant injury scores. Pearl millet seedlings were slightly more resistant than mature plants. Pearl millet supported the most greenbugs and proso the least in seedling trials with greenbugs confined to the three millet species individually and in all possible paired combinations. Since the millet species evaluated were highly resistant, they could serve as substitute crops for sorghum until greenbug‐resistant sorghum cultivars become commercially available.

Fattah, Q. A.; Wort, D. J.

doi: 10.2134/agronj1970.00021962006200050007xpmid: N/A

Bush bean plants, Phaseolus vulgaris L., cultivar Top Crop, were grown from seed for 14 days at 26/21 C day/ night, and 16.1 k‐lux (1500 ft‐c) light with a photoperiod of 14 hours. At the end of this time half the plants were sprayed with a 0.5% potassium naphthenates (KNap) solution. Treated and control plants were then grown 1) under the original light/temperature conditions, 2) at a constant temperature of 26 C with light of 16.1, 10.76, or 5.38 k‐lux, and 3) at a constant temperature of 15 with the three fight intensities. Juvenile growth (plant height; fresh and dry weights of roots, stems, and leaves; number of leaflets; leaflet area) and reproductive growth (number and weight of green pods per plant) were measured 21 and 35 days, respectively, after treatment. The stimulative effect of KNap on both types of growth was evident at all light/temperature combinations, but it was greater at higher temperatures and light intensities. Increments under these conditions were consistently significant at the 0.05 level. The results are consonant with a previous finding that the foliar application of KNap is followed by augmented rates of photosynthesis and greater activity of enzymes of nitrogen metabolism. The larger number of pods may have been the result of more vigorous pollen germination and reduced abscission of young fruits.

Hawkins, B. S.; Peacock, H. A.

doi: 10.2134/agronj1970.00021962006200050008xpmid: N/A

A 3‐year study with Upland cotton (Gossypium hirsutum L.) was conducted at Experiment, Ga., to determine the effects of plants/hill, within‐row hill spacings, and plant populations on lint yield.

Raper, C. D.; Barber, S. A.

doi: 10.2134/agronj1970.00021962006200050009xpmid: N/A

Field experiments were conducted to delineate morphological differences among root systems of 26 soybean varieties (Glycine max (L) Merr.). ‘Aoda’ and ‘Harosoy 63,’ were selected from the 26 varieties and strains as representative of extremes in rooting patterns.

Raper, C. D.; Barber, S. A.

doi: 10.2134/agronj1970.00021962006200050010xpmid: N/A

‘Aoda’ and ‘Harosoy 63’ soybeans [Glycine max (L.) Merr.], representing extremes in gross root morphology, were used in field and growth chamber experiments to study the influence of physiological characteristics of soybean roots on the absorption of nutrients. The efficiency of K uptake per unit root surface was found to be dependent on the variety and the solution concentration of K. The rate of K uptake per unit root surface, or K absorption potential, for Aoda roots was almost double that of Harosoy 63 roots at high levels of K but was nearly equal at low levels. The effect of K concentration on absorption potentials in nutrient solution was independent of concurrent variation of other nutrientions or total growth rate of the plants.