Field survey of kabuli chickpea and dry bean plant spacing uniformity

Non-Peer ReviewedIn an effort to reduce capital expenditures, dryland growers of kabuli chickpea and dry bean in Saskatchewan have been seeding their crops with conventional seeding equipment rather than precision planters. Intra-row plant spacing has been non-uniform, and this project was undertaken to quantify that non-uniformity. Data on within-row plant spacing were collected from twenty-nine commercial growers of dry bean and kabuli chickpea in Saskatchewan during the 2000-growing season. Plant spacing was non-uniform, but the need for equipment modifications to improve plant spacing uniformity is uncertain. Preliminary experiments by the Crop Development Centre have shown a yield advantage for dry bean seeded with more uniform spacing. However, little scientific work has been done on the effect of spacing uniformity on chickpea, and the literature reveals conflicting information among crop types. It is speculated that more uniform plant spacing will improve seed quality and reduce weed competition

The effects of cultivar on nodulation, seed yield, and dinitrogen fixation of dry bean (Phaseolus vulgaris L.)

Non-Peer Reviewe

Assessing dose–response relationships for endocrine disrupting chemicals (EDCs): a focus on non-monotonicity

The fundamental principle in regulatory toxicology is that all chemicals are toxic and that the severity of effect is proportional to the exposure level. An ancillary assumption is that there are no effects at exposures below the lowest observed adverse effect level (LOAEL), either because no effects exist or because they are not statistically resolvable, implying that they would not be adverse. Chemicals that interfere with hormones violate these principles in two important ways: dose–response relationships can be non-monotonic, which have been reported in hundreds of studies of endocrine disrupting chemicals (EDCs); and effects are often observed below the LOAEL, including all environmental epidemiological studies examining EDCs. In recognition of the importance of this issue, Lagarde et al. have published the first proposal to qualitatively assess non-monotonic dose response (NMDR) relationships for use in risk assessments. Their proposal represents a significant step forward in the evaluation of complex datasets for use in risk assessments. Here, we comment on three elements of the Lagarde proposal that we feel need to be assessed more critically and present our arguments: 1) the use of Klimisch scores to evaluate study quality, 2) the concept of evaluating study quality without topical experts’ knowledge and opinions, and 3) the requirement of establishing the biological plausibility of an NMDR before consideration for use in risk assessment. We present evidence-based logical arguments that 1) the use of the Klimisch score should be abandoned for assessing study quality; 2) evaluating study quality requires experts in the specific field; and 3) an understanding of mechanisms should not be required to accept observable, statistically valid phenomena. It is our hope to contribute to the important and ongoing debate about the impact of NMDRs on risk assessment with positive suggestions

Germination and emergence of diverse dry bean varieties under cold and dry conditions

Non-Peer ReviewedDry bean (Phaseolus vulgaris L. ) originated in the tropics and is a warm season crop. In temperate climates such as Saskatchewan, producers face many challenges in growing the crop. Sowing often occurs under suboptimal conditions for crop growth. Planting in early spring (early May) in cold soils results in poor stands while waiting for warmer temperatures in June reduces the length of the growing season. In some years, like 2002, the seedbed conditions at sowing time are cold and dry, which adversely affect stand establishment. Two experiments were conducted in the phytotron at the University of Saskatchewan to address the stand establishment problem in dry bean. The first experiment tested 12 bean varieties/lines for germination ability in petri plates placed in incubation chambers using 20 different temperature regimes. The bean varieties included nine from bean breeding programs across western Canada and one variety from the bean breeding program at Michigan State University and these were compared with two bean lines (G9345, G8823), known to have some cold tolerance, obtained from CIAT (International Centre for Tropical Agriculture) in Cali, Colombia. All genotypes were then tested for emergence in the soil in growth chambers at five temperatures and three soil moisture regimes. From the petri plates, the break-point temperature for bean germination where genotypes varied was 16/16 C (day/night). Temperatures above this were optimal for germination for all bean varieties used in the experiment. The two CIAT lines G9345 and G8823 had superior germination (about 35%) at a lower temperature regime of 14/10 C. Among prairie adapted varieties, AC Polaris had the best germination (25%) under the same temperature regime. Under simulated field conditions, emergence and plant development were slowed down by drought stress or cooler temperatures. Under cool temperatures the two CIAT lines had faster emergence than the bean varieties bred in western Canada. CDC Nighthawk and AC Polaris were most promising among prairie adapted varieties

Gamma Group-The Pale Horse: A proposal in response to a commercial air transportation study ort study

A conventional remotely piloted vehicle (RPV) was designed to operate in a fictional 'Aeroworld' as a 30 passenger aircraft. The topics addressed include: economic/cost analysis, aerodynamics, weight and structures, propulsion, stability and control, and performance

Early maturity strategies in chickpea: pyramiding key genetic traits

Non-Peer ReviewedChickpea (Cicer arietinum L.) is a highly indeterminate species which continues to grow and produce pods through fall, especially in cooler and wetter seasons. This exposes the crop to frost damage resulting in reduced yield and quality. We hypothesized that earliness could be induced through some strategic traits including double podding, reduced internode length and early flowering. The objective of this study was, therefore, to determine the individual and combined effects of these traits on earliness in chickpea. Four single crosses were made: two with the early flowering parent, and one each with the double podding and short internode length parents. Segregating populations of F2–F4 generations were evaluated along with their parents in greenhouse and field trials. Significant genetic variability was observed for days to maturity of lower pods and percent pod maturity at four months after planting. In general, each trait had some effect on earliness, though the magnitude differed, and combining them into a single genotype may help to achieve the desired earliness in chickpea. The F2 population from the multiple cross (gene pyramiding) showed a wide range in maturity. Several had nearly complete maturity of pods at four months after planting. These were more determinate types as judged by smaller increases in height between flowering and maturity stages and uniform maturity of pods

Early flowering, short internode length, and double podding as components of early maturity in chickpea

Non-Peer ReviewedLate maturity, resulting from the indeterminate nature of the crop, is a critical production constraint in chickpea (Kumar and Abbo, 2001). In western Canada, the chickpea crop is often killed by fall frost while seeds/pods are yet filling, which reduces both the quantity and quality of economic yield (grain). It was hypothesized that incorporating early flowering, short internode length and double podding traits may shorten the overall duration of growth in chickpea. Early flowering would advance onset of reproduction, while the latter two traits hasten the rate of pod formation and then progress towards maturity. Hence, a study was initiated to determine the effect of these key traits on time (days) to maturity in chickpea

Plant genomics in lentil breeding: development of a cDNA-based rapid screening method for Ascochyta blight resistance in lentil (Lens culinaris L.)

Non-Peer ReviewedAscochyta blight causes severe crop losses in temperate lentil production areas around the world, including Saskatchewan. At present there is no reliable system available to breeders for identifying blight resistant lentil lines. We are trying to develop a reliable, high throughput and low cost cDNA based system for screening lentil germplasm for polygenic resistance to Ascochyta blight. We have chosen the Ascochyta blight susceptible lentil variety Richlea and the closely related resistant breeding line 1156-2-17A for this study. Lentil plants were inoculated with spore suspensions of Ascochyta under conditions that clearly showed the difference in disease resistance between these lines. Tissue collected from resistant and susceptible lines at different times after inoculation will be used for extraction of total RNA–representing all the genes expressed by the plants in response to Ascochyta infection. Complementary DNA (cDNA) made from these RNA samples along with mock-inoculated controls will be visualized on poly acrylamide gels using the technique of ‘differential display’. We intend to identify the sequences of lentil genes expressed only by the resistant lines in response to Ascochyta infection and use them for developing molecular markers for the resistance trait. cDNA samples made from these plants will also be useful in developing a cDNA library of lentil tissue for future EST projects

Stabilizing yield and quality: early maturing chickpea for the prairies

Non-Peer ReviewedProgress in chickpea breeding has been constrained by lack of good sources of early maturity in the short-season temperate environment of western Canada. We hypothesized that the length of the chickpea life-cycle could be reduced through introgression of strategic genetic traits including short internode, double podding and early flowering. The result showed that both the double podding and early flowering traits had significant beneficial effects by reducing the duration of crop maturity in chickpea in the short-season temperate environment of western Canada. Pyramiding double podding, early flowering and other strategic genetic traits should lead to the development of extra short duration chickpea varieties more suited for cultivation in the Prairies and similar environments