A standardized, accurate, and easy system is needed to describe sunflower (Helianthus annuus L.) plant development. The objective of this study was to develop and describe stages of sunflower plant development in a manner which is simple but accurate.Plants were divided into either Vegetative (V) or Reproductive (R) stages of plant development. Vegetative development is divided into two phases, emergence and true leaf development. The latter stages are determined by the number of true leaves in excess of 4 cm in length. The number of vegetative stages is dependent upon the number of true leaves formed by the plant, making the method flexible but accurate. The reproductive development was divided into nine stages based on the development of the inflorescence from its initial appearance through anthesis to physiological maturity of the seed. This method of describing the stages of development in sunflower is rapid, accurate, greatly simplifies current methods, and can be used to determine plant development for either single or branched inflorescence sunflower.

An understanding of plant response to row spacing and plant density is important in developing effective production systems for new crops. Optimum row spacing and plant population for grain amaranth (Amaranthus spp.) production in the northern Great Plains was evaluated at Prosper and Williston, ND, over 6 station‐years. Amaranth cultivars K283, K343, K432, and MT‐3 were established at populations of 74 000, 173 000, and 272 000 plants ha−1 in 30‐ and 76‐cm row spacings. Grain and biomass yield, plant height, harvest index, harvested plant population, and plant lodging were measured. Grain yields were similar among plant populations at each of the drier environments, averaging 1050 and 410 kg ha−1 for Prosper in 1989 and Williston in 1990, respectively. A 12% yield advantage, 160 kg ha−1, was observed at the lowest compared with the highest plant population at Prosper in 1990, but not in 1992. The main effect of row spacing on grain yield was not significant; however, the interaction of row spacing, plant population, and environment indicated population yield ranking differences at the 30‐cm row spacing among environments but not at the 76‐cm row spacing. The two A. cruentus L. cultivars, K283 and MT‐3, generally produced more grain than the two A. hypochondriacus L. × A. hybridus L. cultivars, K343 and K432, especially in dry environments. When considering yield, plant mortality, and potential harvest difficulties, the moderate population (173000 plants ha−1), 76‐cm row spacing, and generally higher‐yielding A. cruentus cultivars would be recommended.

Understanding soil factors related to cadmium (Cd) uptake and accumulation in plants is important for development of agronomic technologies, and breeding strategy to produce low Cd crops. The objective of the study was to examine the effect of soluble salts (chloride and sulfate) and other soil factors on the Cd concentration in sunflower (Helianthus annuus L.) kernels. Commercial nonoilseed hybrid kernels and soils were sampled from 22 farmer's production fields in North Dakota and Minnesota. The sites sampled included saline and nonsaline variants from 7 soil series. Soils were sampled at four depths. Relationships between kernel Cd level and soil physical and chemical characteristics were examined. The soil pH covered a narrow range (7.3-8.1) at these sampled sites. Regression analysis showed that there was no correlation between kernel Cd and soil pH at any depth. The kernel Cd level was highly correlated with DTPA-extractable Cd in all 4 depths, and with clay content in sub-soils. Soil chloride and sulfate concentrations varied among soil series and within soil series. The absence of a statistically significant effect of soil sulfate level on kernel Cd concentration, indicated that soil sulfate levels did not affect Cd uptake by sunflower plants. However, soil chloride levels in sub-soil were correlated with kernel Cd. The most important soil factor was DTPA-extractable Cd. When chloride was included in the multiple regression equations, R square (R 2) values improved significantly. These results demonstrate that soil chloride concentration is another important factor related to Cd uptake in sunflower plants.

Production of nonoilseed sunflower (Helianthus annuus L.) on certain soil series yields kernels with cadmium (Cd) concentration excess of international market Cd limits. This study was conducted to determine if genetic variability exists among sunflower germplasm for low kernel Cd accumulation, and to select genotypes under varying soil conditions for breeding low kernel Cd cultivar(s). Two-hundred sunflower genotypes were evaluated at four different soil series in North Dakota and Minnesota. Large genetic variation in Cd content was found among genotypes. Kernel Cd concentrations showed continuous variation across the range of 0.31 to 1.34 mg/kg (average for four locations). Although Genotype × Location effect exists, genotypes were ranked similarly in Cd concentration at the four locations. Concentrations of Cd for the genotypes were highly correlated among locations, indicating genotypes performed consistently across the four environments. Results clearly show that genotypes for sunflower differ significantly in kernel Cd concentration, and it appears that this evaluation of 200 genotypes has identified sufficient low Cd germplasm for breeding low kernel Cd genotypes. Soil properties played an important role in Cd uptake and accumulation in sunflower. Data from the four soil series showed that fine textured soils from the Fargo and Grandin locations contained higher levels of diethylenetriaminepentaacetic acid (DTPA) extractable Cd and total Cd, and caused significantly higher sunflower kernel Cd across genotypes. Regressions for kernel Cd on soil measurements were all significant except for pH measures in deeper layer soil. The highly correlated relationship could be used to predict kernel Cd for some soil series which were not part of this study. C ADMIUM is a trace metal that can be absorbed easily from the soil and translocated to food crops. Current U.S. and European dietary intakes of Cd (10-15 Ixg/ day) are below the FAO/WHO provisional tolerable weekly intake (PTWI) (Kowal et al., 1979; Adams, 1991). The PTWI includes a four-fold safety factor for sensitive individuals, and considers lifetime exposure. In fact, no disease was observed in several cases where individuals had Cd intakes far in excess of the PTWI (McKenzie-Parnell, 1987; Strehlow and Barltrop, 1988). However, under extreme conditions where malnourished individuals consumed rice grown on Cd contaminated soil, Cd was reported to accumulate in the kidney cortex and cause renal tubular disease (Nogawa et al., 1987; McKenna and Chancy, 1991; IPCS, 1992). In response to public health concerns resulting from reports of these extreme cases, some nations have established limits for Cd in specific foods. A guide value (Richtwert) for Cd concentration in nonoilseed sunflower was established by Germany at 0.6 mg/kg fresh weight (Germany Richtwert) (Ocker et al., 1991).

Increased interest in alternative sources of oil for edible and industrial uses have stimulated interest in the producti on of new oilseed crops. Spring sown canola (Brassica napus L. and Brassica campestris L.) and crambe (Crambe abyssinica Hochst) have excellent potential to expand the diversity of agricultural crops available to North Dakota producers. The three species are cool season oilseed crops that are adapted to this area. "Canola" is a tradename for varietie of rapeseed from which the oil can be used for hu man con umption, while crambe oil is used for industrial purpose .