The grain amaranths (Amaranthus spp.) were important food staples of ancient American civilizations, and are still important in contemporary Latin America. Because of their nutritional value, the grain amaranths have received significant attention in recent years. Three species predominate among cultivated grain amaranth species: Amaranthus caudatus L., A. cruentus L., and A. hypochondriacus L. Due to variation for morphological characters, accurate classification of amaranth genetic resources is not always possible. The objective of this study was to determine if random amplified polymorphic DNA (RAPD) markers could be used to classify accessions by species. Twenty‐nine previously classified accessions were used as standards. An additional 82 previously unclassified accessions were also investigated. DNA samples from each species were bulked to use as standards for RAPD marker selection. A total of 29 polymorphic RAPD fragments identified in the bulked DNA standards were further tested on all accessions individually. Cluster analysis of RAPD markers separated the 29 known accessions into three distinct groups that corresponded to the morphological species identifications. A species designation was also assigned to all previously unclassified accessions by RAPD analysis. Analysis of 282 polymorphic fragments generated from 80 primers among bulked DNA samples revealed that A. hypochondriacus and A. caudatus are genetically more similar to each other than either species is to A. cruentus. These results suggest that RAPD analysis can be used to efficiently classify grain amaranth accessions by species.

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Quinoa {Chenopodium quinoa Willd) is an important domesticated food crop of the Andean highlands with potential as an alternative crop elsewhere. Among Its most attractive characteristics are the quantity and favorable amino acid balance of the seed proteins. The objective of this study was to characterize quinoa seed proteins by electrophoretic mobility, solubility fractionation, and genetic variability from a wide genetic base. Electrophoretic profiles of denatured albumin, globulin, prolamin, and glutelin solubility fractions demonstrated that quinoa seed polypeptides could be classified as either albumin or globuhn with most predominant polypeptides in the globulin fraction. Insignificant amounts of protein were present in the prolamin fraction and all polypeptides in the glutelin fraction had identical electrophoretic mobilities to albumins and globulins. Three globulin polypeptides of 34.3, 35.6, and 36.2 kilodaltons in size were highly variable within and among the accessions examined and appear to be coded by at least two loci. Twodimensional peptide mapping revealed that these three polypeptides were homologous. These highly variable markers could be used for identification and classification of germplasm and elucidation of systematics and genetic variability within the quinoa germplasm pool. All other major polypeptides were electrophoretically invariant among the accessions examined.

Spring seedings of alfalfa (Medicago satva L.) were established using various seeding rates and establishment treatments. During the year of establishment, average total dry matter yields of alfalfa increased with increased seeding rate. Seeding rates of 24 kg/ha produced alfalfa yields lower than those of the 3 kg/ha seeding rates in cuttings taken the year following seeding. Higher yields of alfalfa were obtained at the lower seeding rates of 3 and 10 kg/ha using EPTC and benefin than at seeding rates of 17 and 24 kg/ha using 2,4‐DB plus dalapon, oats, or check. Weed yields were reduced by all establishment treatments. The effect of establishment treatment was significant during the year of seeding, but not in the year following. Seeding rate effects remained significant throughout six cuttings taken the first two years of the trial. The use of preplant herbicides and seeding rates of 10 or 17 kg/ha were superior in establishing stands of spring seeded alfalfa.

Adequate quantity and quality of cool-season forage are limiting factors in cattle (Bos taurus) producing areas of the subtropics. 'Bigalta' limpograss (Hemarthria altissima (Poir.) Stapf et C.E. Hubb.] has been proposed as a forage with potential to help overcome both problems. A 2-yr study to determine the effect of increasing levels of fall-applied fertilizer on the quality of stockpiled Bigalta limpograss was conducted in central Florida. Eight fertilizer treatments were applied on 10 October each year: (1) 0-0-0, (ii) 34-4-13, (iii) 68-7-26, (iv) 100-11-40, (v) 135-15-54, (vi) 168-18-67, (vii) 200-22-80, and (viii) 400-45-160 kg ha-1 of N-P-K. Forage quality variables were measured in whole plant samples at monthly intervals from 5 December through 5 April, inclusive, and were compared to established National Research Council (NRC) requirements for beef cattle. Yield increases entering into the stockpile period (December) of 285 to 610% (relative to the control) resulted from rates of 68-7-26 kg ha-1 of N-P-K and higher, and these yield increases were maintained through April. Addition of greater than 68-7-26 kg ha-1 of N-P-K consistently increased in vitro dry matter digestibility (IVDMD) crude protein (CP), P, K, and Mn, whereas Zn concentration was decreased by fertilizer application. Acid detergent fiber (ADF), neutral detergent fiber (NDF), and concentrations of Ca, Mg, Fe, and Cu were generally unaffected by fertilizer level. Crude protein, P, and K levels were raised into acceptable NRC ranges, while Zn dropped below the required range as a result of fertilization. Animals grazing stockpiled limpograss of this quality would require supplementation with Zn and Cu during the entire period, while supplementation with CP and P would be required only during February and April, respectively. Both Ca/P and K/(Ca + Mg) ratios were maintained at levels conducive to good beef cattle production throughout the stockpile period.