Alfalfa Growth Stage Sampling Effects upon Molybdenum and Boron Concentrations. (S04-meyer510979-oral)
Authors:
R.D. Meyer* - Univ. of California-Davis D.B. Marcum - Univ of California-McArthur S.B. Orloff - Univ of California-Yreka
Abstract:
The period of time during which plant tissue samples should be taken for diagnosing nutrient deficiencies for many plants is usually rather short. The upper 15 cm section of the alfalfa (Medicago sativa L.) plant is usually sampled at 1/10th bloom growth stage for the micronutrients molybdenum (Mo) and boron (B). The objective of this research was to evaluate the influence that plant stage of growth has upon Mo and B concentrations. Top 15 cm samples of alfalfa plants were collected to locate two field sites, one deficient in Mo (0.2 ppm) and another in B (10 ppm) as well as Mo (0.2 ppm). At the Mo deficient site; 0, 224, 336, 448, 672, 896, and 1344 g Mo ha-1 plus a 4.48 Mg ha-1 lime treatment were applied on March 30, 2000. The second site was established March 9-10, 2001 with Mo alone at 448 and 896 g ha-1 , B alone at 2.24 and 4.48 kg ha-1 and the 4.48 kg ha-1 rate along with the 6 rates of Mo above. Lime alone and in combination with Mo and B treatments were also included. The upper 8-15 cm section of alfalfa was collected when the plants were 15-20 cm and 30-35 cm in height, prebud and 1/10th bloom growth stage. Both Mo and B concentrations remained nearly constant throughout each growth cycle and the year. Higher concentrations resulting from applied nutrients declined during the growth cycle and later years.
Speaker Information: Roland D Meyer, Univ. of California-Davis, LAWR Dept., One Shields Ave., Davis, CA 95616; Phone: 530-752-2531; E-mail: [email protected]
Session Information: Monday, November 3, 2003, 8:40 AM-10:15 AM Presentation Start: 9:15 AM
Keywords: Molybdenum; Boron; Alfalfa; Growth stage nutrient concentrations