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Ammonium And Nitrate Effects On Growth, Development And Nutrient Uptake Of Hydroponic Wheat, Thomas M. Hooten

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The long-term effects of low and high NH₄⁺/ NO₃^- uptake ratios in a system with rigorous control of pH and nitrogen concentration are poorly understood. In two replicate studies, two cultivars of wheat (Triticum aestivum) were grown to maturity with three NH₄⁺/ NO₃^- ratios in hydroponic solution: 0/100, 25/75, and 85/15%. Nitrogen was controlled at ample levels throughout the 70-d life cycle and pH was controlled at 5.8 ± 0.2. An equimolar ratio of NH₄⁺ to Cl^- was used to facilitate charge balance. Nitrogen consumption …

A Study Of Rest Period, Hardiness, And Bud Development Of The 'Concord' Grape, Mervin Gayle Weeks

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The length of the 'Concord' grape rest period was evaluated during 1974-75 and 1975-76. Cuttings were placed in a 25 C growth chamber every two weeks from October through April. Number of days to reach 50 percent full bud swell was plotted to determine rest completion. Seven years of weather data and full bloom dates of 'Concord' grapes from Prosser, Washington were statistically analyzed to give another estimate of rest completion. Rest was terminated after about 830 chill units.

During 1974-75 and 1975-76, T₅₀ temperatures were determined every two weeks for both cambium and primary buds of 'Concord' grapes. …

The Effect Of High Air Temperature And Depth Of Planting On The Emergence And Development Of Selected Grain Sorghum (Sorghum Vulgare) Cultivars, Jhander Orihuela

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The behavior of seedlings of six sorghum cultivars planted at 2.5, 5.0, 7.5, and 10.0 centimeters was studied in growth chambers at air temperatures of 28, 32, 36, and 40 centigrades (daytime).

A day length of 12 hours and a nighttime air temperature 8 centigrades lower than daytime were used throughout.

The cultivars, three hybrids and three varieties, were grown in sand culture. Field moisture capacity was maintained during the period of observation.

After 14 days of growth, data were collected on the emergence percentages, above ground growth, above ground oven dry weights, below ground growth, and below ground oven …

Effect Of Stage Of Seedling Development On Absorption Of Selected Pre-Emergent Herbicides, Pairoj Suchinda

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Using radioautography ¹⁴C simazine, ¹⁴C EPTC, ¹⁴C 2,4-D, ¹⁴14 DCPA and ¹⁴C pyrazon absorption by seeds of bean (Phaseolus vulgaris L.), squash (Cucurbita maxima), corn (Zea mays), onion (Allium cepa) and oat (Avena sativa) was studied. Simazine, EPTC, 2,4-D and pyrazon were absorbed through the seed coat of bean, squash, corn and onion, the amount increasing with time. Little DCPA was absorbed by seeds of bean, squash, onion and oat. Distribution and translocation of ¹⁴C simazine, ¹⁴C EPTC and ¹⁴C pyrazon occurred in …

The Effect Of Limited Moisture Supply At Various Stages Of Growth On The Development And Production Of Hybrid Corn, Ralph E. Campbell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Corn occupies from 25 to 30 percent of the crop land harvested in the United States. In recent years the acreage devoted to corn in this country has been decidedly greater than that devoted to any other cultivated crop. In 1944 its dollar value exceeded the combined values of wheat, barley, rye, grain sorghums, and cotton.

Although South Dakota lies on the northwestern fringe of the corn belt, the corn crop is one of the most important in that state. Corn production in that area is somewhat unstable because of drought. Corn often fails to reach full maturity before the …