Chair: James O. Garner, Mississippi State University Vicechair: Franklin O. Chukwuma, Alcorn State University
James O. Garner, Jr., Mississippi State University, Mississippi State, MS 39762
9:15 RESPONSE OF LEAF AND CANOPY SPECTRAL REFLECTANCE TO DROUGHT AND FUNGAL STRESS IN SOYBEAN
Judge Brown [*], Raj Bahadur, and Abdullah Faruque, Mississippi Valley State University, Itta Bena, MS 38941
Plants of two soybean varieties, traditional DP3588 and high tech. 92B71-Roundup ready, were grown in greenhouse and in the field at Stoneville, MS and East Lansing, MI for primarily drought stress studies. The objective of this study funded by National Aeronautics Space Administration (NASA) at Stennis Space Center was to record the spectral reflectance differences of leaf and canopy stress caused by drought and white mold disease. Plant physiological measurements of leaf water content, leaf water potential and other growth and development data were correlated with the percentage of spectral reflectance of leaf and canopy. Neural network and other statistical techniques were used to analyze plant and soil water relations and the reflectance data acquired with the spectroradiometer. Students were trained in conducting experiments, collecting and analyzing the data. Results of three levels of fungal infection and two levels of drought stress in leaf and canopy are presented. Incorporating this technology in s atellites, economic crops could be monitored world wide for signs of damaging drought stress, which could lead to more reliable predictions of crop yields and remove weather-driven volatility from grain commodity markets. Further research for refining the techniques of predicting by remote sensing crop-damaging effects of drought and possibly irrigating can be economically beneficial.
9:30 LEAD ACCUMULATION OVERTIME IN TWO WEED SPECIES, SESBANIA EXALTATA (RAF.) AND IPOMOEA LACUNOSA L. IN HYDROPONIC CULTURE
Susmita Ghosh [*], Amelya Hardaway, Jennifer N. Ntoni, Aladin Siddig, and Charles Rhyne, Jackson State University, Jackson, MS 39217
The time of exposure to can he an important factor affecting the accumulation in different plant parts. A modified hydroponic growing system was used to suspend two weed species, Sesbania exaltata (Raf.) and Ipomoea lacunosa L. in aqueous solutions of either Hoagland's nutrient solution or 500 mg/L of Pb[([NO.sub.3]).sub.2] in the laboratory. Plants were harvested and separated into shoots and roots at the end of 7, 14, 21, 29, and 35 days of growing. Heights and dry weights were recorded after each harvesting. In case of Sesbania exaltata (Raf.), Pb accumulation in shoots was 1398 (.1%) and 1399 (.1%) mg/kg with root accumulations of 18401 (1.8%) and 7231 (.7%) mg/kg at the end of 7 and 14 days respectively. In case of Ipomoea lacunasa L., shoot Pb accumulations after 7 and 14 days were 1635 (.2%) and 1778 (.2%) mg/kg respectively. Accumulation by roots of the plants was deduced at the end of 14 days (5445 mg/kg) compared to the accumulation (9067 kg) at the end of 7 days. Translocation of Pb to the shoots showed an in with time in both species. Further data will be provided at the time of presentation.
9:45 A COMPARATIVE ANALYSIS OF...