Sunflower (Helianthus annuus L.) is cultivated over a wide range of photoperiod and temperature conditions. The objective of this research was to determine the response of 16 diverse sunflower genotypes to varying photoperiod and temperature. Field research sites were at five locations including Argentina, Alaska, and Hawaii. The photoperiod (daylength + twilight hours) at vegetative emergence (VE) for most sites, except Hawaii and Alaska, ranged from 14.5 to 16.2 h. Within this range there was no evidence that photoperiod affected the time from VEto bud visible stage (R1). Instead, differences in temperature at various sites were responsible for differing rates of development. However, the short photoperiods at VE at Hawaii (11.2 h) decreased development rate and long photoperiods at Alaska (24 h) increased development rate dramatically. A nonparametric method was applied to rank the genotypes into temperature response groups. Four distinct groups resulted for the VE to R1 growth stage intervals, which were classed as very quick, quick, medium, and slow with respect to the time taken to reach RI from VE. Four groups also resulted for the R1 to anthesis (R5.1) time period. The groups for R1 to R5.1 differed from those for VE to Rl. Genotypes within these groups were dissimilar to those for VE to Rl. It was concluded that models used to predict phenological development in sunflower could be based on temperature alone provided photoperiod was within the 14.5 to 16.2 h range. To predict development outside this photoperiod range would require photoperiod be included in the model.

We grew 15 clones of reed canarygrass (Phalaris arundinacea L.) of varying palatability in Indiana and Minnesota and nine clones in Pennsylvania and Alaska over a 2‐year period to determine whether diverse environments would influence alkaloid type, alkaloid concentration, and palatability. We also determined the repeatability of a previously‐established correlation between palatability and total basic alkaloids in reed canary. Major alkaloid types and relative total basic alkaloid concentrations of clones were very repeatable among locations, even though heat units and daylength varied greatly. Of the nine clones grown in all 11 environments, three always contained gramine (3‐dimethylaminomethyl‐indole), two contained N,N‐dimethyltryptamine, and four contained 5‐methoxy‐N,N.dimethyltryptamine. Total basic alkaloid concentrations of clones were highly correlated (r = 0.90 or higher) between all combinations of environments. Palatability ratings of clones grazed by sheep were highly correlated between Minnesota and Indiana (r = 0.91 or 0.96) and between harvests within locations (r = 0.97 or 0.99). Therefore, palatability was a function of plant rather than of animal differences. Total alkaloid concentrations and palatability ratings of clones were highly correlated (r = 0.87 to 0.94) when palatability was rated on a scale of 1 (completely consumed) to 10 (completely rejected). These results confirmed previous findings and substantiated the conclusion that determination of total alkaloids is a valid method of screening for palatability in reed canary.

The objective of the investigation of which this report is a part was to identify chemical elements, organic compounds, or metabolic processes which are associated with genetically controlled P accumulation in corn (Zea mays L.). Two populations of corn, each with subpopulations selected for high and low P in ear leaves, were produced by randomly sib mating the F2 and five and six subsequent generations of an early maturing single‐crossed hybrid and a late maturing single‐cross hybrid. Each single‐cross hybrid contained homozygous inbred lines previously characterized as contributors of low and high concentrations of P to other single‐cross hybrids. In ear leaves, high P was associated with significantly higher, but not substantially different, concentrations of N and B. In seedling plants, grown for three weeks in a growth chamber, high accumulation of P was associated with higher concentrations of N and significantly higher concentrations of S, Ca, Cu, and B.

Alaska has vast areas of undeveloped land with the potential for agricultural expansion. To develop renewable resources from oil royalty monies, the state has initiated a 24,000 ha agricultural demonstration project near Delta Junction, Alaska. Little is currently known, however, concerning the natural fertility of these virgin soils. A 43 factorial experiment was established, with barley (Hordeum vulgare L. var. ‘Otra’) as the test crop, to determine responses to fertilization the first 2 years after clearing on a Typic Cryopsamment soil. Fertilizer was applied before seeding each year at 0, 45, 90, and 135 kg N/ha; 0, 34, 68, and 102 kg P/ha; and 0, 34, 68, and 102 kg K/ha. Grain yields, protein contents, and subsequent soil‐test levels were measured. Nitrogen increased grain yields from 2 quintal/ha with no applied N in 1979 to 25 quintal/ha with 135 kg N/ha and from 4 quintal/ha with no applied N in 1980 to 31 quintal/ha with 135 kg N/ha. The yield response to N was linear throughout the 0 to 135 kg N/ha range in 1979, and both the linear and quadratic regression terms were significant in 1980. Cooler initial soil temperatures, lack of native residual nutrients, or N immobilization may have contributed to lower overall yields in 1979. Grain protein increased linearly with added N both years. Phosphorus increased yield up to 34 kg P/ha, with little response beyond that in either year. In 1979, both P and K were significant in increasing the yield response to N. In 1980, only K increased the yield response to N. Neither P nor K fertilization significantly increased grain protein contents. Multiple‐regression equations were developed to predict grain yields and protein contents with rates of fertilizer applied. When considering only N, P, and K fertilizer additions, equations with relatively high coefficients of determination were obtained for the first 2 years of production (Yield: R2 = 0.929,0.937 for 1979 and 1980; and protein: R2 = 0.684, 0.842 for 1979 and 1980, respectively). Thus, the application of fertilizer accounted for much of the variation in yield and protein contents.