bluuebunny/crossref_metadata_2025 huggingface dataset:
Root growth and soil-water extraction by winter and spring wheat
Authors: Entz M. H. , Gross K. G. , Fowler D. B.
Published: April 2011

Efficiencies of soil-water extraction and use are important factors determining crop productivity in dryland regions. This study was conducted from 1986 to 1988 to compare root growth and soil-water extraction of Norstar and Norwin winter wheat (WW) (Triticum aestivum L.) and Katepwa and HY320 spring wheat (SW). Total root length and rooting depth increased with crop-development stage and level of available soil water. Preanthesis root development was concentrated at soils depths with temperatures greater than 15 °C. Maximum rooting depth at crop maturity ranged from 110 to 130 cm and 60–80% of the total root length was found in the top 50 cm of soil. The rooting patterns of SW and WW were similar at each sampling date despite differences in the stages of development. However, the earlier development of WW resulted in a greater root length for WW by the end of May, an advantage maintained until WW maturity. Differences in the rooting patterns of semidwarf and tall cultivars were not detected. The average change in available soil water (0–130 cm depth) over all cultivars and locations between early May and crop maturity was 5 cm. Ninety-five percent of this water was extracted from the upper 70 cm of soil. Actual rooting depth and maximum depth of soil-water extraction were highly correlated (r = 0.87**). In six of eight trials, WW cultivars used significantly more water from the top 50 cm of the profile in May than SW. In one trial, WW extracted significantly more water from several soil-depth increments than SW over the entire growing season. In the remaining trials, levels of available soil water at SW anthesis and harvest were similar for all cultivars or were higher for WW cultivars because of soil-water recharge by late-season precipitation. Therefore, with the exception of greater early-season water extraction by WW, few consistent differences in soil-water extraction patterns were observed among cultivars considered in this study. Higher water-use efficiency for WW in these trials was attributed to differences in timing of water extraction and not to differences in depth of water extraction.Key words: Canadian prairies, soil-water extraction, root growth, spring wheat, winter wheat, semidwarf, tall, Triticum aestivum
Above- and below-ground net primary production of four barley (Hordeum vulgare L.) cultivars in western Canada
Authors: Xu J. G. , Juma N. G.
Published: April 2011

Information on above- and below-ground primary production for a wide range of agro-ecosystems is needed. The objective of this study was to quantify the shoot and root mass, shoot mass/root mass ratios, and root lengths of four barley (Hordeum vulgare L.) cultivars (Abee, Bonanza, Harrington and Samson) grown in a Black Chernozem in north-central Alberta. The cultivars were grown using a randomized complete block design with three replicates and were sampled at the tillering, stem-extension, heading, and ripening stages. Root mass and root lengths from soil cores were measured. The results showed that (1) shoot mass and root mass of Harrington and Bonanza were not different from those of Abee and Samson, but those of Abee were significantly greater than those of Samson, indicating that the below-ground input of organic matter could be a function of specific cultivar; (2) root mass increased rapidly until the heading stage, and shoot mass increased at a higher rate than roots between the heading and ripening stages, producing a widening of shoot/root ratios with time; and (3) decomposition of very small roots may have contributed to a more rapid decrease in root length than in root mass after the heading stage.Key words: Barley (Hordeum vulgare L.) cultivars, Typic Cryoboroll, root mass, root lengths, shoot/root ratio, soil organic matter
Genetic and agronomic evaluation of short-season Quality Protein Maize
Authors: Spaner D. , Mather D. E. , Hamilton R. I.
Published: April 2011

Development of early-maturing hybrid cultivars of Quality Protein Maize (QPM), a hard-endosperm high-lysine maize (Zea mays L.), could provide a balanced-protein alternative feed crop for northern temperate areas. A set of inbred lines derived from QPM germplasm was used as the base population for three experiments conducted in eastern Canada: an eight-parent one-half diallel analysis, an evaluation of inbred performance, and an evaluation of resistance to Fusarium ear rot. In the diallel analysis, general combining ability effects were significant for grain yield, moisture at harvest, and kernel opacity. Specific combining ability effects were also significant and accounted for 20 and 13% of the genotypic variability for grain yield and moisture at harvest, respectively. Some QPM hybrids yielded well, but they had relatively high levels of grain moisture at harvest, indicating a need to breed for improved adaptation. Within the base population of QPM inbreds, the variation and repeatability for most agronomic traits and for resistance to Fusarium ear rot appeared to be adequate to allow development of agronomically superior QPM inbreds and hybrids for northern temperate maize growing regions.Key words: Quality Protein Maize, opaque-2, repeatability, diallel, agronomic potential, Fusarium graminearum
Chemical and mechanical conditioning for field drying of Trifolium pratense L.
Authors: Narasimhalu P. , Kunelius H. T. , McRae K. B.
Published: April 2011

First growth and regrowth of Trifolium pratense L. ’Florex’ (red clover) were used to study the effect of conditioning on the moisture content (MC = g water g−1 DM) under field conditions. Chemical conditioning using desiccant agents and mechanical conditioning with rollers were applied separately or combined. Swath MC was measured for 52 h after cutting in five trials. In all five trials, the MC of field dried, unconditioned red clover was unsuitable for baling 52 h after cutting (range: 0.25–3.8 MC). In three of the five trials, conditioning failed to lower the MC below that of unconditioned red clover because of rain, even when DM yield was moderate (2.2 t ha−1 in trial 5). Under rain-free weather, the low-rate chemical or mechanical conditioning applied alone or high-rate chemical and mechanical conditionings applied together, to moderate and high-yielding stands of red clover (2.4 and 4.2 t DM ha−1 in trials 4 and 2, respectively), reduced the MC to 0.2 or lower, and provided the practical benefit of storing hay at least a day earlier than unconditioned red clover.Key words: Clover (red), hay, desiccant, roller conditioner, field drying
Influence of annual ryegrass and barley seeding rates on intercrop forage yield and quality
Authors: Thompson D. J. , Stout D. G.
Published: April 2011

Annual ryegrass (Lolium multiflorum Lam. ’Maris Ledger’) was seeded at rates ranging from 5 to 30 kg ha−1 as either a monocrop or an intercrop with 50, 100 or 150 kg ha−1 of spring barley (Hordeum vulgare L. ’Diamond’). When ryegrass is intercropped with barley, cuts 1 and 2 are usually ensiled and the remainder of seasonal production is pastured (the equivalent of two forage cuts). Monocropped annual ryegrass produced 91% as much dry matter (DM) in the silage cuts as intercropped annual ryegrass and barley but produced 105% as much pasture. Over the season, monocropped ryegrass produced 11.1 t ha−1 of forage compared with 11.7 t ha−1 for intercropped annual ryegrass and barley. Among the intercropping treatments, increased barley seeding rate resulted in greater cut 1 yields, but this was offset by reduced cut 2 yields, so barley seeding rate did not affect the yield of DM for silage. Only 50 kg ha−1 of barley seed was required to obtain maximum yearly forage yields when intercropping with annual ryegrass. No more than 10 kg ha−1 of ryegrass seed was required for optimal yield when monocropping, and no more than 15 kg ha−1 when ryegrass was intercropped with barley. Monocropped ryegrass produced superior quality forage for silage. When quality was weighted for the relative yields of cuts 1 and 2, the monocrop averaged 16% protein and 72% in vitro disappearance of dry matter (IVDDM) compared with 12% protein and 58% IVDDM for the intercrops. Among the intercrops, increasing barley seeding rate from 50 kg ha−1 to 150 kg ha−1 did not affect the protein content of silage cuts, but it decreased IVDDM from 60% to 56%. Pasture forage quality was not affected by barley seeding rate.Key words: Intercropping, annual ryegrass, barley, seeding rate, yield
Identification of timothy cultivars by SDS-PAGE analysis of seed storage proteins
Authors: Cai Q. , Bullen M. R.
Published: April 2011

SDS-PAGE analysis of seed proteins was carried out to identify the cultivars in the forage crop, timothy (Phleum pratense L.). Nineteen cultivars of timothy were examined. Among them five were from Europe and fourteen from North America. In total fifty protein bands were detected in mature seed extract by SDS-PAGE followed by Coomassie blue staining. Except for two pairs, all the cultivars were differentiated by SDS-PAGE analysis of seed storage proteins. In the electrophoretic profile, no protein bands were found to be specific either to European or to North American cultivars which is an indication of their genetic similarity. Twelve samples of cultivar Toro harvested from Alberta and Manitoba (Canada), Idaho and Minnesota (USA) were compared and no significant differences were found in their seed protein banding patterns, which suggests environmental stability of timothy seed proteins.Key words: SDS PAGE, timothy cultivar identification, seed storage proteins
Growth, phenology, and yield components of barley and wheat grown in Alaska
Authors: Dofine S. M.
Published: April 2011

The comparative growth, phenology, and yield components of three early-maturing barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.) cultivars were studied during the 1989–1991 growing seasons at Palmer, Alaska. Barley cultivars produced an average of 1.1 more leaves than wheat, and had a smaller (4.5 growing degree days/leaf) phyllochron interval. The early maturity of barley relative to wheat was due mainly to its ability to fill and ripen grain under cool conditions.Key words: Barley, wheat, subarctic, phyllochron
AC Stirling safflower
Authors: Mündel H.-H. , Morrison R. J. , Huang H. C. , Kiehn F.
Published: April 2011

AC Stirling is a dual-purpose birdseed and oilseed safflower cultivar, averaging 35% oil content. Availability of AC Stirling to farmers permits an expanded production of safflower in the southern prairies, as it is acceptable in the oilseed market. AC Stirling significantly outyields Saffire and matures, on average, 3 d later. The yellow flower distinguishes AC Stirling from Saffire, which has orange–red flowers.Key words: Carthamus tinctorius L., safflower, cultivar, dual-purpose
Enhancement of cold hardiness in apple trees by paclobutrazol, thidiazuron and flurprimidol
Authors: Coleman W. K. , Estabrooks E. N.
Published: April 2011

Two-year-old apple trees (cv. Spur McIntosh/MM.106) were treated once during September 1987 and again in September 1988 with the growth regulators paclobutrazol, thidiazuron or flurprimidol alone or in different combinations. Seasonal changes in electrolytic leakage at test stress temperatures of −15, −25 and −35 °C were recorded from October to May. During the 2-yr study, there was a well-defined acclimatization phase until early February followed by a deacclimatization phase during February–May. The treatment that produced greatest increases in apple twig hardiness was a mixture of paclobutrazol, thidiazuron and flurprimidol. In 93% of the test dates, this treatment gave a lower injury value than the control at the −25 °C stress temperature and 66% gave significantly (P < 0.05) lower injury levels. Chemical treatments increased the hardiness of apple wood throughout the fall, winter and spring periods without altering the pattern of seasonal changes in hardiness level. Multivariate analyses indicated that treated shoots were less sensitive than the controls to mild temperatures during the winter period.Key words: Apple, cold hardiness, growth regulators
Air circulation in growth chambers stunts tomato seedling growth
Authors: Liptay A.
Published: April 2011

Air circulation, generally an integral part of environmentally controlled plant growth chambers, inhibited tomato (Lycopersicon esculentum Mill.) seedling growth seismomorphogenically. Tomato seedlings were grown either in a growth chamber having an air movement of 0.5–0.7 m s−1 or in a chamber with no air circulation. Growth inhibition was noticeable with as little as 15 min of daily exposure to air circulation, and a continuous exposure gave the greatest amount of growth inhibition. The air-movement effect on seedling growth was transient and required a continued daily exposure to air movement for growth inhibition. Continuous air circulation inhibited seedling growth to such an extent that in a two-factor experiment (i.e., air movement and water stress) the water-stress effects were completely hidden by the air-movement effect. The results have important implications for tomato plant growth experiments in chambers equipped with air circulation: seedling growth may be affected more by the inherent air circulation in the growth chamber than by an experimental treatment.Key words: Tomato growth inhibition, air movement, seismomorphogenic, short seedlings
Leaf epicuticular wax, an antixenotic factor in Brassicaceae that affects the rate and pattern of feeding of flea beetles, Phyllotreta cruciferae (Goeze)
Authors: Bodnaryk R. P.
Published: April 2011

Crop brassicas with waxy leaves (> 1000 mg kg−1) were fed upon by flea beetles, Phyllotreta cruciferae (Goeze) (Coleoptera: Chrysomelidae), at a low rate, and feeding occurred predominantly at the edges of leaves. Species with non-waxy leaves (< 240 mg kg−1) were fed upon at a high rate, and feeding occurred randomly throughout the leaf. The regression of feeding rate upon amount of epicuticular wax had an R2 = 0.64, indicating that 64% of the feeding variation of flea beetles on diverse species and cultivars of Brassicaceae was explained by a single factor regression. Feeding studies on low-wax (eceriferum, cer) Brassica mutants confirmed that leaf epicuticular wax is an important antixenotic factor that affects the rate and pattern of feeding of flea beetles. The CC genome of B. oleraceae was identified as the source of the waxy-leaf character that gives rise to the low feeding rate and edge-feeding pattern of flea beetles. The digenomic amphidiploid B. napus (AACC genome), derived from the monogenomic diploids B. oleraceae (CC genome) and B. rapa (AA genome), and the digenomic amphidiploid B. carinata (BBCC genome), derived from monogenomic diploids B. oleraceae and B. nigra (BB genome), had waxy leaves and an edge-feeding pattern and rate similar to members of the B. oleraceae group. All other monogenomic diploids (AA, BB, DD, SS, RR) and digenomic amphidiploids (AABB) not possessing the CC genome had non-waxy leaves, a high rate of feeding and a random feeding pattern by flea beetles.Key words: Brassica, epicuticular wax, feeding, resistance, Phyllotreta cruciferae
Row-spacing and seed-rate effects on winter wheat in Ontario
Authors: Teich A. H. , Welacky T. , Hamill A. , Smid A.
Published: April 2011

This study was carried out to determine if winter wheat in southwestern Ontario should be grown in rows narrower than the conventional 18 cm and if the current recommended seed rate of 3.2 million seeds ha−1 (msh) is adequate. We compared the effect of 10- and 20-cm row spacings and 1.6, 3.2, and 6.4 msh seed rates on grain yield, weed growth and yield of underseeded clover. Row spacing at a constant seed rate did not affect yield. With increasing seed rate there was an increase in yield, mainly through more heads per unit area, which more than compensated for a decrease in seeds per head. Narrow rows reduced the number of lamb’s-quarters and the overall weed count. The optimum seed rate for grain yield was 6.4 msh for ratios of seed cost:crop value less than 1.34. Key words: Narrow rows, weeds, yield, economic optimum
Effet du labour printanier et des cultures intercalaires de trèfle rouge sur le rendement du maïs-grain
Authors: Claude P.-P. , MacKenzie A. F. , Mehuys G. R. , Coulman B. E.
Published: April 2011

Because corn (Zea mays L.) production may cause soil degradation, cultural systems to minimize this degradation are required. Intercropping of corn with legumes may reduce such degradation, but effects on corn yields must be evaluated. The objective of the study was to determine the effect of a red clover (Trifolium pratense L.) intercrop in conjunction with spring ploughing on the yield of grain corn on two soil types: a Chicot sandy loam and a Ste-Rosalie clay loam. A split-plot experimental design established on each soil consisted of three cultural practices as the main plots and three rates of N fertilizer as the split plots. Corn yields decreased significantly from 1987 to 1989 in conjunction with an increase in the biomass produced by the intercropped red clover and the weeds that it harboured. However, spring ploughing of this biomass rather than fall incorporation had no negative effects on the yield of corn. Although in the case of fall ploughing the presence of red clover did allow for the accumulation of additional inorganic nitrogen in the soil in the spring, the competitiveness of the red clover and especially of the weeds caused a decrease in the yield of grain corn. The use of intercropped red clover for soil conservation in Quebec may thus be limited if a tight control over weeds is not maintained. Key words: Intercropping, Zea mays, Trifolium pratense, nitrogen, spring ploughing
The effects of tillage systems on the economic performance of spring wheat, winter wheat, flax and field pea production in east-central Saskatchewan
Authors: Lafond G. P. , Geremia R. , Derksen D. A. , Zentner R. P.
Published: April 2011

The long-term viability of Canadian prairie agriculture depends on the ability to arrest soil degradation caused by wind and water erosion and excessive tillage. The challenge is to develop crop-production systems that are economically viable and environmentally sustainable. The objective of this study was to quantify the short-term economic performance of field pea (Pisum sativium L.), flax (Linum usitatissimum L.) and spring and winter wheat (Triticum aestivum L.) grown under three tillage-management systems. The economic analysis was based on a tillage × crop rotation experiment started in 1986 and involving zero tillage (ZT), minimum tillage (MT) and conventional tillage (CT) and three 4-yr crop rotations. The economic analysis considered only costs associated with purchased inputs and machinery. The effects of method of tillage management on herbicide and fuel use were also determined for each crop. Costs of production were similar for all tillage systems and crop types. Net returns were higher for field pea, flax and spring wheat grown on stubble using ZT and MT than when CT was used, because of higher grain yields. Net returns were similar for winter wheat grown on stubble and for spring wheat grown on fallow for all tillage-management systems. Fuel consumption was highest for CT, intermediate for MT and lowest for ZT for all crops except winter wheat. In contrast, herbicide use was greater for ZT and MT than for CT for al crops except winter wheat; no differences were observed among tillage systems for this crop because it was always seeded directly into standing stubble. The shift from CT to ZT or MT systems did not increase costs of production or reduce short-term economic returns. ZT and MT had higher production potential than CT because increased soil-moisture conservation generally provided higher net returns. ZT used less fuel but more herbicides than MT and CT. Key words: Stubble cropping, fallow cropping, zero, minimum, conventional
Effect of tillage on nitrogen response in corn (Zea mays L.) after established alfalfa (Medicago sativa L.)
Authors: Aflakpui G. K. S. , Vyn T. J. , Hall M. R. , Anderson G. W. , Swanton C. J.
Published: April 2011

The effect of tillage and added nitrogen fertilizer on first- and second-year corn after an established alfalfa stand was investigated in field studies near Woodstock, Ontario, Five rates of nitrogen fertilizer, ranging from 0 to 160 kg ha−1, were evaluated to determine their influence on corn growth and yield in both no-till and conventional tillage systems in the first and second years of corn following alfalfa. In the first year of corn after alfalfa, grain yield and harvest index were significantly lower with no-till than with conventional tillage only in 1988. First-year grain yields were independent of nitrogen fertilizer rates in both 1988 and 1989. There was no tillage by nitrogen rate interaction in either year indicating that additional nitrogen fertilizer was not required to achieve optimum corn yields with no-till relative to conventional tillage. Yields of second-year corn increased with nitrogen rate in both 1989 and 1990. Tillage systems had no apparent influence on nitrogen availability to corn grown after an established alfalfa stand. Key words: Tillage, alfalfa, nitrogen
Capsule closure and seed discoloration in flax from exposure to various moisture and temperature conditions
Authors: Gubbels G. H. , Kenaschuk E. O.
Published: April 2011

Mature flax (Linum usitatissimum L.) capsules closed completely within 50 min after exposure to free water, but not all closed completely when exposed to high humidity. In capsules placed between wet paper towels, 50% of the seeds discolored to dark brown or black in 3.4, 5.6, 6.3 and 12.8 d after exposure at 20, 15, 10 and 5 °C, respectively. Microorganisms were implicated in the discoloration processes. Key words: Flax, Linum usitatissimum L., seed weathering, seed discoloration
Growth and ochratoxin production of Aspergillus alutaceus on seed of wheat and rapeseed cultivars
Authors: Madhyastha M. S. , Marquardt R. R. , Frohlich A. A.
Published: April 2011

Five cultivars each of wheat and rapeseed were tested for their ability to support fungal growth and ochratoxin A (OA) and B (OB) production over a period of 30 d at 28 °C. All cultivars supported fungal growth and the production of OA. The ranges for wheat and rapeseed were 1.4–5.0 and 7.8–29.9 mg g−1 for glucosamine and 42–237 and 21–300 μg g−1 for OA, respectively. Only rapeseed supported OB production, and this ranged from 114 to 1295 μg g−1. Rapeseed cultivars appeared to be a better substrate for the fungus than wheat. Differences within wheat and rapeseed could be attributed to genetic or environmental effects. Key words: Wheat, rapeseed, varietal differences, fungal growth, ochratoxin A and B production
Frost tolerance of maturing flax
Authors: Bonner D. M. , Gubbels G. H. , Kenaschuk E. O.
Published: April 2011

In field and laboratory studies, frost damage to immature flax (Linum usitatissimum L.) increased as temperatures fell below −2 °C. In general, considerable damage occurred where temperatures dropped to the −3 to −5 °C range for immature seed, −4 to −5 °C for leaves, pedicels and capsule tissue, and −6 to −7 °C for stems. Key words: Flax, Linum usitatissimum L., frost tolerance
RCAT Angora soybean
Authors: Ablett G. R. , Tanner J. W.
Published: April 2011

RCAT Angora is a mid-late Maturity Group II soybean (Glycine max (L.) Merr.) cultivar with excellent yield potential and resistance to most races of phytophthora root rot caused by Phytophthora megasperma f. sp. glycinea (RMG) found in Ontario. Key words: Soybean, cultivar description
CDC Teal hard red spring wheat
Authors: Hughes G. R. , Hucl P.
Published: April 2011

Teal is an early-maturing hard red spring wheat best adapted to the Black soil zone of western Canada. It combines early maturity with good yield potential, increased kernel size and leaf and stem rust resistance. It was developed at the University of Saskatchewan from a three-way cross involving BW514 (Nainari 60/Huelquen), Benito and BW38 (UM953A/Neepawa; UM953A = Sonora 64/Tezanos Pintos Precos). Key words: Triticum aestivum, cultivar description, bread wheat
Effects of forced ventilation at different relative humidities on growth, photosynthesis and transpiration of geranium plantlets in vitro
Authors: Yue De , Gosselin André , Desjardins Yves
Published: April 2011

Shoots of geranium (Pelargonium × hortorum Bailey ’Hollywood Red’) were cultured under forced ventilation with air of different relative humidities (RH). In comparison with those grown under conventional in vitro conditions, plantlets grown under forced ventilation had greater dry weight of both shoots and roots. Grey pigment zonation, which appears on leaves grown in either the greenhouse or the field, was not observed on leaves cultured under conventional in vitro conditions but was found on leaves cultured under forced ventilation. Forced ventilation at 100% RH, or at 100% RH before rooting and 46% after rooting, did not have a significant effect on the photosynthetic capacity of leaves. However, leaves grown at 46% RH after rooting showed a much lower transpiration rate than leaves grown under conventional in vitro conditions or in vessels ventilated with air of 100% RH. Key words: Pelargonium × hortorum, micropropagation, forced ventilation, growth, photosynthesis, transpiration
Tomato yield-evapotranspiration relationships, seasonal canopy temperature and stomatal conductance as affected by irrigation
Authors: Tan C. S.
Published: April 2011

The effects of irrigation on evapotranspiration (ET), yield, crop canopy temperature and stomatal conductance of tomatoes (Lycopersicon esculentum Mill.) were investigated in Fox sandy loam in the sub-humid region of southwestern Ontario between 1979 and 1982. Optimum yields were obtained with 300–400 mm of total applied water (rainfall plus irrigation). There appeared to be a distinct threshold seasonal ET value of 88 mm, below which yield was negligible and above which yield rose linearly with the seasonal ET rate. The values of crop canopy temperature and leaf stomatal conductance were not significantly different among different levels of irrigation. Leaf stomatal conductance was significantly lower for non-irrigated tomatoes in a dry year indicating that they were subjected to the greater degree of water stress. Key words: Lycopersicon esculentum, irrigation, water stress
Response of bush and upright plant type selections to white mold and seed yield of common beans grown in various row widths in southern Ontario
Authors: Park S. J.
Published: April 2011

White mold, caused by Sclerotinia sclerotiorum (Lib.) de Bary, is an important disease in common bean (Phaseolus vulgaris L.) production areas. It reduces seed yield and lowers the quality of beans. Development of the disease is thought to be affected by plant canopy type (architecture), and by genetic resistance. This study determined the effect of plant type and row width on white mold and seed yield. Three short bush/vine and four semi-determinate upright genotypes were tested in narrow (30 cm) and wide (60 and 80 cm) rows for 2 yr in a field prone to white mold development. Incidence and disease index increased as row width became narrower. The upright type was infected less than the short bush type. Ex Rico 23, which is a short vine, open canopy type, was moderately resistant to the mold. A tall upright selection, A55, showed the lowest mold infection; it was significantly less than that of Ex Rico 23. Seed yield of all genotypes increased as row width decreased even though there was an increase in white mold incidence. Stiff-strawed upright types had less lodging. To reduce white mold, cultivars should have lodging resistance, narrow canopied upright plant type and genetic resistance. Development of the upright plant types allows for narrow-row production and direct combining. Key words: Dry edible bean, Phaseolus vulgaris, white mold, Sclerotinia sclerotiorum, plant type, row width, seed yield
Limitations of the K:N ratio in the nutrient feed of drip-irrigated greenhouse tomatoes as a crop-management tool
Authors: Papadopoulos Athanasios P. , Khosla Shalin
Published: April 2011

Greenhouse tomato cultivars were grown over three spring (1987, 1988 and 1989) and two fall (1987 and 1988) seasons in soil to assess the yield and fruit-quality effects of the potassium (K):nitrogen (N) concentration ratio in the fertigation solution. In the spring, the K:N ratio was varied over the first 11 wk following planting to provide a high, medium or low K:N ratio in the fertigation solution. The K:N ratio in the fertigation solution varied from 14:1 (week 1) to 2:1 (week 11) or from 8:1 (week 1) to 2:1 (week 11) or remained steady at 2:1 (weeks 1–11) for the high-, medium- and low-K:N treatments, respectively. In the fall the K:N ratio varied from 3:1 (week 3) to 9:1 (week 10), or from 2.3:1 (week 3) to 6:1 (week 10), or from 1.5:1 (week 3) to 3:1 (week 10) for the high-, medium- and low-K:N treatments, respectively. The marketable yields harvested averaged around 7.5 kg plant−1 in the spring and 2.5 kg plant−1 in the fall. The K:N ratio in the fertigation solution had no significant effect on early, or final, total or marketable yield. Similarly, there were no significant effects on fruit quality. It was concluded that provided a recommended overall osmotic effect (measured as electrical conductivity) of the nutrient solution is maintained, fertilizers can be selected and used on the basis of cost, or other important criteria, without concern for yield loss due to undesirable K:N ratio effect. Key words: Lycopersicon esculentum, marketable yield
Microfloral infection and quality deterioration of sunflower seeds as affected by temperature and moisture content during storage and the suitability of the seeds for insect or mite infestation
Authors: White N. D. G. , Jayas D. S.
Published: April 2011

Sunflower seed, cultivar Interstate 7111, was stored at 10, 20, 30, and 40 °C and 35, 45, 55, and 75% RH for up to 12 mo. At 75% RH fungal growth was extensive and free fatty acids (FFA) increased rapidly under all temperature regimes. Based on a threefold increase in FFA (1.5%) seed can be stored for 12 mo: at 6% moisture content (MC) and 30 °C; 7% MC and 20 °C; or 8% MC and 10 °C. Seed germination remained above 80% for 12 mo at 10 and 20 °C and 35, 45, and 55% RH; it declined to 70% at 30 °C and 45% RH, but at 55% RH it fell to 30% at 6 mo and 0% at 12 mo. Seed germination decreased rapidly at 40 °C. The incidence of microfloral infection by Penicillium spp. and Aspergillus spp. directly affected increased FFA, decreased germination, and infection was frequent at > 75% RH and different fungal species predominated at different temperatures. Eight species of stored-product beetles and one species of mite were placed on whole sunflower seed, ground seed, shells, or seed meat. Only Oryzaephilus surinamensis, O. mercator, Tribolium castaneum, and T. confusum multiplied appreciably in 2 mo, mainly on ground seed or seed meat. The Oryzaephilus spp. multiplied as much on sunflower seed as on ground wheat controls. Infestation of sunflower seeds by these pests is likely. Key words: Sunflower seed, storage, free fatty acids, germination, fungi, Insecta, Acari
Effects of planting date, irrigation and rain on infection, disease severity and pod discoloration caused by Alternaria alternata (Fr.) Keissler in bean (Phaseolus vulgaris L.)
Authors: Tu J. C.
Published: April 2011

Black-pod disease of bean, caused by Alternaria alternata, was shown to be more severe on early-seeded than on late-seeded crops. This contradicts an earlier view that early spring planting could reduce this disease. Beans should be planted late, harvested soon after maturity and dried rapidly. Overhead irrigation during the growing season reduced the establishment of epiphytic populations on the leaves and consequently reduced the incidence of infestation. After bean plants matured, epiphytic Alternaria began to grow on the pods when they came in contact with rain or dew. Key words: Bean, Alternaria black pod, planting date, irrigation, rain
Influence of agronomic practices on canopy microclimate and septoria development in no-till winter wheat produced in the Parkland region of Saskatchewan
Authors: Tompkins D. K. , Fowler D. B. , Wright A. T.
Published: April 2011

In areas with favourable growing conditions, high seeding rates (SRs), narrow row spacings (RSs) and nitrogen fertilization (N) are required before high yield potentials of winter wheat (Triticum aestivum L.) are realized. Changes in these variables produce changes in crop-canopy microclimate that may influence the development of foliar pathogens. This study examined the relative differences in crop-canopy microclimates due to different RS and SR combinations and determined the effect of SR, RS and N fertility on septoria (Septoria nodorum Berk. and Septoria tritici Rob. ex Desm.) development on normal height and semi-dwarf cultivars grown under no-till in the Parkland region of Saskatchewan. The daily mean value for solar radiation penetrating to the base of the crop canopy was 1100 μmol m−2 s−1 for 36-cm RS. This was 30% higher than the 845 μmol m−2 s−1 observed for 9-cm RS. The increased light interception by the canopy was associated with higher dry matter production and grain yield. During peak periods, wind speed was 56% higher within the 36-cm RS canopy than within the 9-cm RS canopy. Increased duration of leaf wetness was associated with 9-cm RS and 140-kg-ha−1 SR treatment. Cooler air temperature and higher RH within the canopy occurred for the 9-cm RS – 140-kg-ha−1 SR treatment. Differences in air temperature and RH between the 9-cm RS – 140-kg-ha−1 SR and the 36-cm RS – 35-kg-ha−1 SR treatments were smaller at night and greater during the day. The maximum differences occurred at mid-morning and mid-afternoon, when the 9-cm RS – 140-kg-ha−1 SR canopy was 1.5 °C cooler and had a 4.5% higher RH than the 36-cm RS – 35-kg-ha−1 SR canopy. Septoria severity increased when SR increased from 35 kg ha−1 to 140 kg ha−1. Septoria severity was not influenced by RS. Septoria severity was greater on the flag leaf of the semi-dwarf cultivar Norwin than on the tall cultivar Norstar. Increased N fertility reduced septoria severity in one trial. These observations demonstrated that, in addition to the influence on yield potential, high SR and narrow RS produce a canopy microclimate that is favourable for the development of septoria. Key words: Seed rate, row spacing, N fertility, Septoria sp., Triticum aestivum, canopy microclimate
Response to sublethal herbicide application in early growth of seven Xanthium strumarium populations
Authors: Zhang Jianhua , Cavers Paul B. , Jasieniuk Marie
Published: April 2011

Seven populations of Xanthium strumarium L. collected from wetlands and arable fields were examined for their responses to three levels of bentazon application. Significant differences were observed among populations for all traits measured. Contrasts between the wetland and arable populations indicated significant differences in some traits, especially the length and width of the fifth internode. These measurements are closely related to plant biomass, and they were reduced greatly in the wetland populations after bentazon treatment. However, an overall comparison using canonical discriminant analysis failed to show differences between the wetland and arable populations, suggesting that differences in response to herbicide between the two ecotypes may be due to changes in a few traits relating to fitness. Key words: Growth, weed, herbicide, bentazon, cocklebur, Xanthium strumarium
Forage potential of pulse-cereal mixtures in central Alberta
Authors: Jedel P. E. , Helm J. H.
Published: April 2011

The use of pulse crops for animal feed is a production option for farmers in western Canada. In this study, the forage potential of three pea (Pisum sativum L.) cultivars, Magnus, Tipu, and Trapper, and one fababean (Vicia faba L.) cultivar, Outlook, grown as pure stands and in mixtures with the barley (Hordeum vulgare L.) cultivar Leduc, the oat (Avena sativa L.) cultivar Cascade, or the triticale (× Triticosecale Rimpani Wit.) cultivar Wapiti were assessed at Lacombe, AB from 1988 to 1991. The dry matter (DM) yields of the pea and fababean cultivars were similar at 8–9 t ha−1. Although there were year-to-year and pulse-to-pulse variations, the mixtures with oat yielded more DM (10–11 t ha−1) than the mixtures with barley or triticale or the pure stands of the pulses (8–10 t ha−1). The fababean pure stand and mixtures had high moisture contents (> 70%) at harvest. Outlook had the highest protein content; Tipu and Trapper, intermediate; and Magnus, the lowest. While the mixtures with triticale and barley had protein contents similar to the pure stands of pulses (14–15%), the mixtures with oat had lower protein contents (12%). Only in 1990 did the oat mixtures have higher protein yields ha−1 than the pure stands. The mixtures had similar acid detergent fiber (ADF) contents to the pure stands of pulses. If the choice of a pulse-cereal mixture is for high quality with maintenance of protein content, mixtures with barley or triticale should be selected over those with oats. Key words: Silage, protein, ADF, pulse-cereal mixtures
Seed hull content in field pea
Authors: Ali-Khan S. T.
Published: April 2011

Seed hull content in field pea was used as a measure of estimating fiber content. Screening of field pea cultivars and germplasm showed a range of 7.2–12% in seed hull content. There was a significant effect of growing sites and years on hull %. No significant correlation was detected between hull % and yield, maturity or seed size but cultivars containing high hull % produced purée with poor viscosity. Key words: Field pea, Pisum sativum, seed hull, fiber
Susceptibility of inbred lines of oilseed rape, Brassica napus, to feeding damage by the crucifer flea beetle, Phyllotreta cruciferae (Goeze) [Coleoptera: Chrysomelidae], and its inheritance
Authors: Lamb R. J. , Palaniswamy P. , Bodnaryk R. P. , McVetty P. B. E. , Jeong S. E.
Published: April 2011

Seventy-seven inbred lines of Brassica napus L. were assessed for antixenosis to damage by die crucifer flea beetle, Phyllotreta cruciferae (Goeze). The resistance was quantified by measuring the level of damage inflicted on seedlings of each line in laboratory tests. One of these lines, M12, was more susceptible than another line, L19, in a series of replicated tests, but individual seedlings could not be identified as resistant or susceptible because inter-seedling variation in the damage level was high. The F3 families from reciprocal crosses between L19 and M12 showed segregation for the resistance, demonstrating that the antixenosis has a genetic basis. Two or more genes probably control the expression of the resistance, but the number could not be estimated. Electrophoresis of seed endosperm proteins revealed a band, P-74, that occurred in M12 and eight cultivars of B. napus, but not in L19. This banding pattern was inherited as a simple recessive allele, but it proved not to be linked with the resistance in the F3 families. Further screening of B. napus for highly resistant genotypes and identification of linked genetic markers are needed to establish agronomically useful levels of flea beetle resistance in this crop. Key words: Insecta, resistance, canola, electrophoresis, endosperm proteins
Fertility management in canola production
Authors: Grant C. A. , Bailey L. D.
Published: April 2011

A review of the world literature on canola, a type of oilseed rape with low glucosinolates and low erucic acid, indicated that canola is a heavy user of plant nutrients. Canola requires as much or more nitrogen than cereal crops. Although canola requires more P than cereal crops for optimum yield, it may require lower levels of P fertilizers, as it is very effective at utilizing both soil P and applied P. During growth, canola takes up large quantities of K, but only a small amount is removed in the seed, so canola appears to require less fertilizer K than cereals. Canola requires more S than do cereal crops and S deficiencies may severely restrict canola yield, particularly where high levels of N are applied. Micronutrient deficiencies in canola are not common, but may occur on specific soils. Increases in canola yield with application of B, Zn and Cu have been reported in field studies. Balanced nutrition of canola is important to ensure optimum seed yield and quality as well as the most economic response to applied fertilizer. Key words: Brassica campestris, Brassica napus, nitrogen, phosphorus, potassium, sulphur
Genotypic, intraplant, and environmental variation in stomatal frequency and size in wheat
Authors: Wang H. , Clarke J. M.
Published: April 2011

Stomatal characteristics are of interest in physiological studies and in the development of cultivars to improve productivity or stress resistance. In wheat (Triticum spp.) previous studies show contradictory results for intraplant variation in stomatal frequency and size. Our objective was to investigate the effects of genotype, environment and intraplant variation on stomatal frequency, size and the total stomatal area per unit leaf area in tetraploid (T. turgidum L. var. durum) and hexaploid (T. aestivum L.) wheat, and to assess requirements of sample size and allocation for determining genotypic differences. Significant variation was found in stomatal frequency within leaves (position on leaf and between surfaces), among leaf positions within plants, and with leafage in both wheat species. To obtain consistent genotypic differences, fully expanded leaves from the same plant position should be taken, and frequency counts should be made on the same leaf surface and at a constant position within leaves. Although stomatal frequency was negatively correlated with stomatal size, the total stomatal area per unit leaf area usually increased with increasing stomatal frequency. Stomatal frequency increased under dry or high light intensity environments. There were no significant changes in genotype rank order for stomatal frequency in different environments. Increasing the number of leaves sampled had a greater impact on precision of determination of stomatal frequency than increasing the number of microscope fields counted within leaves. Key words: Stomata, Triticum aestivum L., T. turgidum L. var. durum
Aconitase and glucose phosphate isomerase variation in hexaploid wheat
Authors: Hassett Sylvia W. , McMillin David E. , Johnson Jerry W.
Published: April 2011

The purpose of this study was to determine if isozyme variation could be found in wheat (Triticum aestivum L. em. Thell) for the isozymes aconitase, alcohol dehydrogenase and glucose phosphate isomerase; these isozymes are encoded by genes on wheat chromosomes with loci conferring pest resistance. Two hundred and fifty wheat accessions were examined for variation in the isozymes aconitase and alcohol dehydrogenase using starch gel electrophoresis. Accessions were chosen at random from a collection of hexaploid wheat lines from all over the world. In addition, twenty-one accessions which exhibited unusual variation for either endopeptidase or aconitase were examined for glucose phosphate isomerase variation using isoelectric focusing. While no isozyme variation was seen for alcohol dehydrogenase, variation was detected for aconitase and glucose phosphate isomerase. In addition, the glucose phosphate isomerase phenotypes of wheat lines with the 1B-1Rs and 1A-1Rs wheat-rye translocations were distinguished. Therefore, evaluation of glucose phosphate phenotypes could potentially be used in wheat improvement programs to identify plants which are homozygous for wheat-rye translocations involving chromosome 1. Key words: Triticum aestivum, isozyme variation, wheat improvement
Residue production of semidwarf and conventional wheat genotypes
Authors: Clarke J. M. , DePauw R. M.
Published: April 2011

Crop residues are important components of conservation tillage systems, but little information is available on genotypic differences in residue production, particularly with regard to the differences between semidwarf and conventional (tall) genotypes. The objective of this research was to determine the influence of genotype and environment on height and non-grain residue production of semidwarf and conventional-height wheat (Triticum spp.). Locally adapted semidwarf and conventional height common (T. aestivum L.) and durum (T. turgidum L. var. durum) wheat genotypes were grown in up to three environments (fallow, irrigation, and stubble) during the years 1983 to 1988, and 1991. Residue yields of semidwarf and conventional genotypes, and of short and tall conventional genotypes, were compared within and between wheat classes. Within classes, residue yield of semidwarf genotypes tended to be lower (P < 0.05) than that of conventional genotypes. Residue yield of the semidwarf HY320 from the high yielding Canada Prairie Spring class was similar to that of the conventional Canada Western Red Spring cultivar Neepawa. Within the conventional height group, the tallest genotypes tended to have higher residue yields than the shortest genotypes, although the differences were not consistent. Residue yield differences among genotypes were associated with variation in grain yield, plant height, and harvest index. Key words: Triticum aestivum L., T. turgidum L. var. durum, harvest index, plant height.
Comparative growth analysis of Brassica napus and Brassica juncea under Swedish conditions
Authors: Kjellström C.
Published: April 2011

Indian cultivars of Brassica juncea were tested in field experiments at the research farm of the Swedish University of Agricultural Sciences, Uppsala, to determine their agronomic performance under Swedish climatic conditions. In this study, production and development of a B. juncea cultivar of Indian origin and a Swedish B. napus cultivar were compared in a growth analysis during 1987–1990. Plants were harvested at approximately weekly intervals from emergence to maturity, and separated into leaves, stems, pods and seeds. Area indices of leaves, stems and pods were calculated, and dry weight of each plant component was determined. On an average of 4 yr, the total growing period was similar for both cultivars, 107 d or ca. 1030 growing degree days (GDD), with an earlier onset and a shorter duration of flowering for B. juncea. Dry weights of all vegetative plant components, especially stems, reached higher maximum levels in the highly branched B. juncea cultivar than in the B. napus cultivar. By the end of the flowering stage, B. napus had accumulated a significantly higher percentage of final total dry matter than B. juncea. After flowering, the crop growth rate was significantly higher in B. juncea, 0.54 g m−2 GDD−1, than in B. napus. Seed yield level was similar in both species, and in year 1990 ca. 2.2 t ha−1 was harvested. Key words: Brassica juncea, Brassica napus, growth analysis, area index
AC Linora flax
Authors: Kenaschuk E. O. , Rashid K. Y.
Published: April 2011

AC Linora, a medium early-maturing oilseed flax (Linum usitatissimum L.), with high yield potential in both early and late seeding, was released by Agriculture Canada, Research Station, Morden, Manitoba, in 1991. The cultivar has high oil content and high oil quality. It is immune to North American races of rust caused by Melampsora lini (Ehrenb.) Lév. and moderately resistant to wilt caused by Fusarium oxysporum f. sp. lini. Key words: Flax, oilseed, Linum usitatissimum L., cultivar description