It has been observed in other wheat growing regions that stands that are thin rarely have problems with low grain protein. The purpose of this study was to determine if this is indeed the case in Arizona. A study was conducted at Maricopa where the durum varieties Duraking, Minos, and Turbo were sown at rates from 30 to 360 lbs seed/acre. Seeding rate had no effect on grain protein or yield in this study. The reported effects of thin stands on grain protein may be related to low yield rather than seeding rate per se.

Field pea is an important crop in western Canada. The current recommended seeding rate in field pea is 88 plants m-2. As certain pea genotypes have the ability for increased branching, it may be possible for a producer to seed at a lower plant population without reduced yield or to choose a highly branched cultivar to have reduced risk of yield loss under conditions of poor emergence. The objective of this research was to determine how differences in branching among seven representative pea cultivars affected crop yield at different seeding rates, and to determine if branching affected the competitive ability of pea cultivars. In the plant population experiment, seven pea cultivars were seeded at five target plant populations (10, 30, 90, 120, and 150 plant m-2) during 2005 and 2006 at Rosthern and Saskatoon, Saskatchewan. The competition experiment involved eight cultivars being seeded at 50 plants m-2 to measure competitiveness with weeds. Plant emergence, number of branches, light interception, harvest index and grain yield were measured. Growth, seasonal temperature and rainfall were near normal in 2005. Severe terminal drought occurred in 2006 which may have lead to decreased yields. Branching was greatest at low plant densities and decreased as plant density increased. Grain yield increased as plant density increased until it plateaued at 80 100 plants m-2. The response of yield to plant density differed to some extent among cultivars, with CDC Acer and CDC Bronco achieving more of their potential yield at lower densities, while Carrera and Courier required higher densities to reach the same proportion of potential yield. Weed biomass was lowest in plots sown to longer vined cultivars with normal leaf type. Branching habit did not affect the competitiveness of pea cultivars. Potential exists to plant highly branched cultivars to reduce risk of yield loss in situations where low plant emergence might occur.

There is a demand for new recommendations for pulse seeding rates that will meet the needs of organic farmers. This study was conducted to determine the impact of seeding rate on N2 fixation and N accumulation in lentil and pea and to examine the impact of different seeding rates of lentil and pea on the productivity and N-uptake (i.e., N benefit) in a subsequent wheat crop.<p> The study was performed between 2005 and 2007. Two sites were selected each year of the two-year experiment on certified organic farms in central Saskatchewan. At each location, lentil (<i>Lens culinaris</i> L.) cultivar CDC Sovereign and field pea (<i>Pisum sativum</i> L.) cultivar CDC Mozart were each seeded at five different rates. Wheat (<i>Triticum aestivum</i> L.) cultivar AC Elsa was sown as a non-fixing reference crop at a plant population density of 250 seeds m-2. In the following year, wheat was sown to assess the effect of the pulse seeding rate treatments on the succeeding crop.<p> The pulse crop seeding rates significantly affected the quantity of N2 fixed of lentil and field pea, although %Ndfa (80 to 88% and 79 to 85% for lentil and pea, respectively) typically was unaffected by seeding rate. Yield parameters of following wheat crop were not affected by the seeding rates of the previous pulses. Typically, N contributions increased with increasing seeding rates of both lentil and pea, but there was no detectable difference in N uptake by the following wheat grown on the both pulse stubble. The different seeding rates of organically grown lentil and field pea have impacts on the amount of N2 fixed and N contribution to the soil. However, the differences in N remaining in the soil at different seeding rates of the pulse crops were not detectable in the following wheat crop and the soil N in the following year.

The inability to control wild oat (Avena fatua L.) in oat (Avena sativa L.) crops by chemical means limits growers to the use of cultural control methods. Delayed seeding is the most commonly used measure; however, both crop yield and quality may suffer as a result. The objectives of this research were to i) determine if western Canadian oat genotypes differ in competitive ability, ii) determine the effect of increased plant populations on oat wild oat competition, iii) determine the effect of wild oat competition on oat quality, and iv) establish whether or not oat genotype and seed size affect germination characteristics under low temperature and moisture stress. These objectives were tested using field and laboratory experiments. Morphologically diverse oat genotypes differed in their ability to both tolerate wild oat competition and interfere with wild oat growth. Although low yielding under weed-free conditions, when subject to wild oat competition CDC Bell was able to maintain yield, reduce wild oat seed production and was the most competitive of the genotypes examined. Increased plant populations achieved through higher seeding rates provide an effective means by which to enhance the competitive ability of oat genotypes resulting in reduced yield loss and wild oat seed production. With the exception of the percentage of wild oat seed in harvested oat samples, wild oat competition had minimal effect on oat quality. Differences in germination characteristics were observed among the genotypes examined. Conclusions that emerge from this research are that i) oat genotypes differ in their ability to tolerate and interfere with wild oat competition, ii) increased plant populations may provide a long-term control measure that may reduce weed seed contribution to the soil seedbank as well as enhance the competitive ability of oat, iii) wild oat competition has minimal effect on milling oat quality with the exception of percentage of wild oat seed in harvested samples and iv) that median germination time varies among oat genotypes.

The inability to control wild oat (Avena fatua L.) in oat (Avena sativa L.) crops by chemical means limits growers to the use of cultural control methods. Delayed seeding is the most commonly used measure; however, both crop yield and quality may suffer as a result. The objectives of this research were to i) determine if western Canadian oat genotypes differ in competitive ability, ii) determine the effect of increased plant populations on oat wild oat competition, iii) determine the effect of wild oat competition on oat quality, and iv) establish whether or not oat genotype and seed size affect germination characteristics under low temperature and moisture stress. These objectives were tested using field and laboratory experiments. Morphologically diverse oat genotypes differed in their ability to both tolerate wild oat competition and interfere with wild oat growth. Although low yielding under weed-free conditions, when subject to wild oat competition CDC Bell was able to maintain yield, reduce wild oat seed production and was the most competitive of the genotypes examined. Increased plant populations achieved through higher seeding rates provide an effective means by which to enhance the competitive ability of oat genotypes resulting in reduced yield loss and wild oat seed production. With the exception of the percentage of wild oat seed in harvested oat samples, wild oat competition had minimal effect on oat quality. Differences in germination characteristics were observed among the genotypes examined. Conclusions that emerge from this research are that i) oat genotypes differ in their ability to tolerate and interfere with wild oat competition, ii) increased plant populations may provide a long-term control measure that may reduce weed seed contribution to the soil seedbank as well as enhance the competitive ability of oat, iii) wild oat competition has minimal effect on milling oat quality with the exception of percentage of wild oat seed in harvested samples and iv) that median germination time varies among oat genotypes.

Field pea is an important crop in western Canada. The current recommended seeding rate in field pea is 88 plants m-2. As certain pea genotypes have the ability for increased branching, it may be possible for a producer to seed at a lower plant population without reduced yield or to choose a highly branched cultivar to have reduced risk of yield loss under conditions of poor emergence. The objective of this research was to determine how differences in branching among seven representative pea cultivars affected crop yield at different seeding rates, and to determine if branching affected the competitive ability of pea cultivars. In the plant population experiment, seven pea cultivars were seeded at five target plant populations (10, 30, 90, 120, and 150 plant m-2) during 2005 and 2006 at Rosthern and Saskatoon, Saskatchewan. The competition experiment involved eight cultivars being seeded at 50 plants m-2 to measure competitiveness with weeds. Plant emergence, number of branches, light interception, harvest index and grain yield were measured. Growth, seasonal temperature and rainfall were near normal in 2005. Severe terminal drought occurred in 2006 which may have lead to decreased yields. Branching was greatest at low plant densities and decreased as plant density increased. Grain yield increased as plant density increased until it plateaued at 80 100 plants m-2. The response of yield to plant density differed to some extent among cultivars, with CDC Acer and CDC Bronco achieving more of their potential yield at lower densities, while Carrera and Courier required higher densities to reach the same proportion of potential yield. Weed biomass was lowest in plots sown to longer vined cultivars with normal leaf type. Branching habit did not affect the competitiveness of pea cultivars. Potential exists to plant highly branched cultivars to reduce risk of yield loss in situations where low plant emergence might occur.

There is a demand for new recommendations for pulse seeding rates that will meet the needs of organic farmers. This study was conducted to determine the impact of seeding rate on N2 fixation and N accumulation in lentil and pea and to examine the impact of different seeding rates of lentil and pea on the productivity and N-uptake (i.e., N benefit) in a subsequent wheat crop.<p> The study was performed between 2005 and 2007. Two sites were selected each year of the two-year experiment on certified organic farms in central Saskatchewan. At each location, lentil (<i>Lens culinaris</i> L.) cultivar CDC Sovereign and field pea (<i>Pisum sativum</i> L.) cultivar CDC Mozart were each seeded at five different rates. Wheat (<i>Triticum aestivum</i> L.) cultivar AC Elsa was sown as a non-fixing reference crop at a plant population density of 250 seeds m-2. In the following year, wheat was sown to assess the effect of the pulse seeding rate treatments on the succeeding crop.<p> The pulse crop seeding rates significantly affected the quantity of N2 fixed of lentil and field pea, although %Ndfa (80 to 88% and 79 to 85% for lentil and pea, respectively) typically was unaffected by seeding rate. Yield parameters of following wheat crop were not affected by the seeding rates of the previous pulses. Typically, N contributions increased with increasing seeding rates of both lentil and pea, but there was no detectable difference in N uptake by the following wheat grown on the both pulse stubble. The different seeding rates of organically grown lentil and field pea have impacts on the amount of N2 fixed and N contribution to the soil. However, the differences in N remaining in the soil at different seeding rates of the pulse crops were not detectable in the following wheat crop and the soil N in the following year.

No description available.

Three studies applicable to organic management and cultivation of birdsfoot trefoil (BFT, Lotus corniculatus L.) are presented here. The first is a histological analysis of lignification in BFT stems that supports recommendations to harvest BFT at approximately 6 weeks of regrowth, or early bloom. Lignification decreases digestibility and is correlated with high shear force required to break BFT stems. The sixth internodes from the base of 10 BFT and two alfalfa plants were sampled during 15 weeks of midsummer regrowth. The lignified xylary ring reached its maximum radial width by 7.5 weeks of regrowth, and full bloom was reached by 6.5 weeks of regrowth. The second study evaluated establishment of BFT, which competes poorly with weeds and produces low yields during establishment. At an organic, irrigated site in northern Utah the effects of autumn vs. spring seeding, seeding rates of 3, 7 20, and 34 kg pure live seed (PLS) ha-1 and use of a companion crop on 3 years of annual yields and foliar cover of mature stands were determined. First year yields increased linearly with seeding rate (P≤0.05). Use of a companion crop reduced first year yields, and did not reduce weed cover. Autumn seeding of BFT alone, following harvest of a summer crop, is recommended for irrigated production. The final study evaluated BFT establishment on five organic dairy farms in souther Idaho and northern Utah. Participating producers broadcast seeded 4-ha BFT pastures in the fall at a rate of 25 kg PLS ha-1. All farms achieved high BFT density, but only two farms had higher BFT than weed density. These two farms also had high BFT cover the spring following autumn seeding, and their pastures produced 6000 to 7600 kg of dry matter ha-1 by 20 June 2012 and supported grazing for the remainder of the summer. Establishment was enhanced by crop rotation and sprinkler irrigation.

‘CL151’ a Clearfield long-grain rice cultivar, was released in 2008, based upon excellent agronomic characteristics, including excellent yield and moderately resistant rating for lodging. Further experience has indicated it’s susceptibility to lodging. Lodging can reduce harvest efficiency, yield, and cause grain quality loss. The purpose of this research was to evaluate multiple management practices such as nitrogen rates and timings, seeding rate, trinexapac-ethyl application, potassium, and fungicide application to mitigate lodging for CL151. The results of this research indicate that N rate and application timing largely influence lodging incidence and grain yield. Fungicide application decreased, but did not eliminate lodging, while potassium application did not impact lodging or grain yield. Seeding rate also has a significant impact on grain yield and lodging incidence. Trinexapac-ethyl also decreased lodging incidence, but negatively impacted grain yield which was most evident when applied at 48 g ha-1 and applied at PD +14d growth stage.