The Effect of Seeding Date, Seeding Rate, and Applied Nitrogen on the Yield of Canaryseed

Non-Peer ReviewedA major problem when growing canaryseed is the year to year fluctuation in yield experienced by Saskatchewan farmers. The cause of this fluctuation in yield is not known, but suggestions include seeding rate, seeding date , nitrogen rate, potassium, sulfur, aphids, a fungus called leaf mottle, and lack of moisture during grain filling. To determine the cause of this fluctuation in yield and to optimize the agronomics of canaryseed production research examining the effect of planting date, seeding rate and nitrogen rate at three locations, Melfort, Indian Head and north of Swift Current (Stewart Valley) was started in 1999. In 2000, with additional funding from the Potash and Phosphate Institute of Canada, and Agriculture and Agri-Food Canada work was started on potassium and sulfur. Two full seasons have been completed. In 1999 all four experiments were conducted at the three locations. No major problems occurred at Indian Head or Swift Current during the growing season. In addition the seeding rate and nitrogen rate experiments were conducted at Weyburn. At Melfort, in 1999 hail damaged the plots in July reducing yield and the reliability of the data. At Weyburn, bird damage and drought at the end of the season reduced yields. In 2000, the Septoria leaf Mottle experiments were lost at Indian Head due to flooding and also at Weyburn because of excessive wild oat pressure. Seeding date had a large effect on yield at several locations. The first seeding date had the highest yield at Swift Current and Melfort while the second seeding date was highest at Indian Head in 1999 and in a preliminary experiment conducted in 1998. In 2000, the first seeding date had the highest yield at Indian Head and Melfort. While seeding date did not affect yield at Swift Current or Saskatoon. The yield of canaryseed did not readily respond to changes in seeding rates. Slight increases in yield occurred at Melfort and Weyburn in 1999 and 2000 as the seeding was increased. In addition canaryseed yield did not respond to increasing rates of nitrogen fertilizer. Controlling Septoria leaf mottle with Tilt did provided a yield response 4 out of 6 site years. The two sites where a response did not occur was at Stewart Valley. The Canaryseed yield was significantly increased by potassium at two locations but the results are two preliminary to make general conclusions

Partial Homology Relations - Satisfiability in terms of Di-Cographs

Directed cographs (di-cographs) play a crucial role in the reconstruction of evolutionary histories of genes based on homology relations which are binary relations between genes. A variety of methods based on pairwise sequence comparisons can be used to infer such homology relations (e.g.\ orthology, paralogy, xenology). They are \emph{satisfiable} if the relations can be explained by an event-labeled gene tree, i.e., they can simultaneously co-exist in an evolutionary history of the underlying genes. Every gene tree is equivalently interpreted as a so-called cotree that entirely encodes the structure of a di-cograph. Thus, satisfiable homology relations must necessarily form a di-cograph. The inferred homology relations might not cover each pair of genes and thus, provide only partial knowledge on the full set of homology relations. Moreover, for particular pairs of genes, it might be known with a high degree of certainty that they are not orthologs (resp.\ paralogs, xenologs) which yields forbidden pairs of genes. Motivated by this observation, we characterize (partial) satisfiable homology relations with or without forbidden gene pairs, provide a quadratic-time algorithm for their recognition and for the computation of a cotree that explains the given relations

Adaptation of oilseed crops in Saskatchewan

Non-Peer Reviewe

Management of fertility in the pulse-based cropping systems of western Canada

Non-Peer Reviewe

Effect of “starter” N and P on nodulation and seed yield in field pea, lentil, and chickpea in semiarid Canadian prairies

Non-Peer Reviewe

On Symbolic Ultrametrics, Cotree Representations, and Cograph Edge Decompositions and Partitions

Symbolic ultrametrics define edge-colored complete graphs K_n and yield a simple tree representation of K_n. We discuss, under which conditions this idea can be generalized to find a symbolic ultrametric that, in addition, distinguishes between edges and non-edges of arbitrary graphs G=(V,E) and thus, yielding a simple tree representation of G. We prove that such a symbolic ultrametric can only be defined for G if and only if G is a so-called cograph. A cograph is uniquely determined by a so-called cotree. As not all graphs are cographs, we ask, furthermore, what is the minimum number of cotrees needed to represent the topology of G. The latter problem is equivalent to find an optimal cograph edge k-decomposition {E_1,...,E_k} of E so that each subgraph (V,E_i) of G is a cograph. An upper bound for the integer k is derived and it is shown that determining whether a graph has a cograph 2-decomposition, resp., 2-partition is NP-complete

Building an alliance to map global supply networks

The global economy consists of more than 300 million firms, connected through an estimated 13 billion supply links [see supplementary materials (SM)], that produce most goods and services. It has long been unthinkable to analyze the world economy at the firm level, even less so its intricate network of supply chain linkages. This blind spot has left us ill-prepared to make fast and well-informed decisions, begetting, for example, prolonged shortages in raw materials and critical medical supplies during the COVID-19 pandemic. Now, the availability of new data and recent methodological advances allow us to reconstruct a large share of the global firm-level supply network. Because mapping this network is likely to continue to improve, it is essential to initiate a discussion about responsible management and effective use of these data for the global public good. This requires new collaborative efforts between nations, their public institutions, international organizations, the private sector, and scientists

Economics of preceding crops and nitrogen application rates for canola and barley production in western Canada

Non-Peer ReviewedThe objective of this study was to evaluate the economic effects of a range of legume and non-legume preceding crops and N rates on costs and net revenue (NR) of canola (Brassica napus L.), barley (Hordeum vulgare L.) and canola-barley rotation under various environmental conditions. Legumes such as field pea (Pisum sativum L.) and lentil (Lens culinaris Medik.) as preceding crop generated higher net revenues for the following crops canola and barley than when wheat (Triticum aestivum L.) and canola were the preceding crops. Although faba bean (Vicia faba L.) grown as a green manure produced the highest annual net revenues for the following crops canola and barley, this contribution was not enough to compensate for the loss of income during the green manure production year. Therefore, growing faba bean as a green manure was not economical. Response of net revenue to N rates was mainly linear or quadratic, and N was optimal at 60 to 90 kg ha-1 at most sites. The results indicate that growing legumes for seed prior to canola can increase net revenues of canola and subsequent barley

Contribution of legume preceding crops to improve economic and non-renewable energy use efficiency of canola production

Non-Peer Reviewe

Nitrogen cycling and budget in crop rotations as influenced by preceding crops and N fertilization

Non-Peer Reviewe