Histoplasma capsulatum was recovered from the liver and spleen tissues of a species of predominantly insectivorous bats as well as from soil collected in a man-made harborage at Madden Air Field in the Republic of Panama.Although the recovery of the fungus Histoplasma capsulatum from soils enriched with bat or bird guano has been documented (1), successful attempts to recover it from the tissues of bats have not been reported. More than 100 bats were collected from a building adjacent to the air strip of the now-abandoned Madden Air Field, Republic of Panama. Within the building, the roosting habits of the bats were such that the guano collected could be related to the predominant bat using that particular roost. Three species of bats were recovered, Chilonycterus rubiginosa fusca, Carollia perspiculata azteca, and Phyllostomus hastatus panamensis. The latter species, an omnivore, was not examined for the presence of Histoplasma capsulatum. In addition to the bats and guano collected within the building, soil samples were taken at the entrance, under the eaves, and at the rear of the building. Thirty Chilonycterus rubiginosa fusca were killed in groups of five; livers and spleens were pooled and made into a homogeneous suspension with the aid of sterile sand, mortar, and pestle. The supernatant from this suspension was then inoculated onto two bloodfortified mycosel (2) plates and into each of five mice (0.2 ml intraperitoneally). Forty-five Carollia perspiculata azteca were processed in similar fashion, after a holding period of 22 days at the Corozal Veterinary Quarantine Station. Thus a total of six pools of Chilonycterus and nine pools of Carollia liver-and-spleen suspensions were sampled for the presence of Histoplasma capsulatum. None of the plates inoculated directly with the suspensions of liver and spleen revealed the presence of H. capsulatum. In addition, none of the mice inoculated with the tissues of Carollia perspiculata azteca yielded Histoplasma capsulatum when killed at varying times after inoculation. In contrast, two of the Chilonycterus pools (A445 and A447) yielded positive cultures. The Abstract. Histoplasma capsulatum was
Acala 44 cotton was grown near Yuma, Ariz. on irrigated Superstition loamy sand having a steep productivity gradient from one end of the field to the other. Effects of soil moisture, N rate, and plant spacing, each at 3 levels in a factorial experiment, were determined for vegetative growth, fruiting, N uptake, yields, and ginning and fiber characteristics. Yields were increased substantially by N, and significantly, but less so by moisture and spacing. The spacing effect was limited to the second of 2 pickings. Considering the 4 direct factors which determine cotton yields (total flowers, percent boll‐set, boll size, and percent lint) fertilizer affected 2 and spacing 4 of these factors. The precision of the experiment did not permit a decision as to how moisture increased yields since none of the 4 factors were affected significantly. Cotton growth and production were unsatisfactory where substantial cuts were made in leveling the field before planting. The range of yields among individual plots varied almost 800% with a maximum of 2.51 bales and a mean of 1.28 bales of lint per acre. In spite of the large productivity gradient and resultant variations in growth and yield, relative response to a given treatment was remarkably consistent.
Synopsis Moisture and nitrogen variables influenced sweet corn production at various growth stages‐seedling establishment, internode elongation, and pollination and grain development in a 3‐year investigation. Components contributing directly to yield were plant population, ears per plant, and weight per ear (including rows of kernels per ear, kernels per row, and weight per kernel). All were affected by irrigation and/or N fertilization.
Alfalfa was grown on Superstition loamy fine sand on the Yuma Mesa for the 4‐year period, 1949–52, to evaluate the effects of moisture and phosphate variables on hay production and associated factors. The three moisture treatments were based on tension levels, tensiometers being installed at 9 depths from 6 to 120 inches. A total of about 125,000 tensiometer readings were recorded during the 4 years. Ten phosphate (superphosphate) rates and/or frequencies varying from 100 to 1,300 pounds P2O5 for the 4‐year period were employed as subplots in the split plot design. Average annual hay yields for the 4‐year period varied from 6.4 to 12.3 tons per acre, being greatly affected by either moisture or P level. Small frequent irrigations and an initial fertilizer application of more than 200 pounds P2O5 plus 100 pounds P2O5 annually appeared to be the goals to approach. Phosphorus movement was largely limited to the surface 18 inches, which was less than expected. As measured by tensiometers the depth for the greatest relative activity of roots decreased with decreasing moisture tension, increased with decreasing supplemental phosphate, and increased with increasing temperatures. Soil sampling during a 32‐month period revealed that for “dry”, “medium”, and “wet” treatments respectively, 80, 74, and 27% of the available moisture and 72, 82, and 85% of the total water utilized by the plant was removed from the surface 48 inches of soil. During a 3‐year period the mean water use per day varied from 0.21 to 0.25 inch, the greatest amount being used in the “wet” or low‐tension treatment. Water used per ton of hay produced varied from 7.1 to 16.5 inches, high rates of moisture and phosphate giving greatest efficiency. The alfalfa stand thinned rapidly, correlation analysis indicating a reduced stand was an important cause for declining yields. Root grading analyses at the termination of the experiment demonstrated that moisture and phosphate levels had no effect upon root shape and nematode infection. Moisture and/or phosphorus had significant effects on crown and root weight, root diameter, amount and distribution of feeder roots, and crown‐ and root‐rot. A barley crop was grown following the alfalfa to measure residual productivity levels due to previous moisture and phosphate variables. The only significant difference was caused by moisture, the “dry” treatment resulting in the greatest grain yields.
Synopsis A three‐year barley study with irrigation and nitrogen variables at Yuma, Arizona, demonstrated the importance of investigating components leading to yield such as: plants per unit area, heads per plant, seeds per head, and individual size or weight per seed. Nitrogen rate increased barley yields appreciably, predominantly by increasing heads per plant and seeds per head. Moisture utilization efficiency—pounds of grain per acre‐inch of water—was favored by higher N rates and the drier moisture regimes.
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