Visual quality is one of the major factors that determine the market value of field pea (Pisum sativum L.). Breeding for improved visual quality of pea seeds is currently a challenging task, because of the complexity and lack of sound genetic knowledge of the traits. The objectives of this research were to characterize the genetic basis and identify the genomic regions associated with four key visual quality traits (cotyledon bleaching in green pea, greenness in yellow pea, and seed shape and seed dimpling in both green and yellow types) in field pea. Biochemical and gene expression profiling to understand the molecular basis of post-harvest cotyledon bleaching in green pea was also addressed. Two F5:6 recombinant inbred line (RIL) populations (90 lines from Orb X CDC Striker cross, and 120 lines from Alfetta X CDC Bronco cross) were developed and evaluated for visual quality traits in two locations in Saskatchewan, Canada in 2006 and 2007. The four quality traits evaluated all displayed a continuous range of expression with moderate to high heritability. Two genetic linkage maps utilizing 224 markers (29 simple sequence repeat (SSR) (from Agrogene) and 195 amplified fragment length polymorphism (AFLP)) and 223 markers (27 SSR and 196 AFLP ) were constructed for the Orb X CDC Striker population and the Alfetta X CDC Bronco population, respectively. Multiple quantitative traits (QTL) mapping detected major QTLs on linkage group (LG) IV and LG V, as well as location- and year-specific QTLs on LG II and LG III associated with green cotyledon bleaching resistance. Nine QTLs controlling yellow seed lightness, three for yellow seed greenness, 15 for seed shape and nine for seed dimpling were detected. Among them, 5 QTLs located on LG II, LG IV and LG VII were consistent in at least two environments. The QTLs and their associated markers will be useful tools to assist pea breeding programs attempting to pyramid positive alleles for the traits. The bleaching resistant cultivar CDC Striker had a slower rate of chlorophyll degradation in cotyledons and a higher carotenoid to chlorophyll ratio in seed coats than the bleaching susceptible cultivar Orb when seed samples were exposed to high intensity light. An oligo-nucleotide microarray (Ps6kOLI1) was utilized to investigate the gene expression profiles of CDC Striker and Orb seed coats at different developmental stages. It clearly indicated that the expression of genes involved in the production and accumulation of secondary metabolites was significantly different between these cultivars. The results of both biochemical and gene expression studies suggested the bleaching resistance in CDC Striker was not due to the accumulation of chlorophyll pigments in the cotyledons, but rather due to the ability of seed coats to protect them from photooxidation. Accumulation of specific carotenoids which could bind with the reaction center protein complex more effectively and accumulation of phenolic secondary metabolites which could enhance the antioxidant properties and structural integrity of the seed coats may lead to the bleaching resistant phenotype. Therefore, breeding green pea cultivars with higher seed coat antioxidant properties would improve both visual and nutritional quality. This research has provided several insights into molecular approaches to improve field pea visual quality for food markets.

Field pea (Pisum sativum L.) is an important grain legume in western Canada. Growers can, however, be reluctant to include pulse crops such as field pea in their rotation because they are poor competitors with weeds. This thesis research was conducted to determine whether competitive differences exist among semi-leafless field pea cultivars and to determine the mechanism(s) driving competitive differences. Cultivars included in the studies were chosen on the basis of varying seed size and vine length, which are traits known to confer competitive ability. Differences in competitive ability were identified among cultivars as yield loss ranged from 9% to 31% and 14% to 31% for model weed seed return. However, cultivars were inconsistent in their competitive ranking as cultivars typically performed well for one metric, but not both. None of the traits measured in this study correlated with competitive ability. The greenhouse research was unable to identify the mechanism responsible for these competitive differences. Focal pea plants generally responded to the presence of below-ground neighbours by allocating more resources to shoot production. Therefore, semi-leafless field pea cultivars exhibit differences in below-ground responses to neighbours and it may be useful to include this as part of the selection criteria in breeding programs.

No description available.

Sitona lineatus L. (Coleoptera: Curculionidae) is a pest of Pisum sativum L. (Fabales: Fabaceae) and managing it is a challenge because of its fecundity, migratory behavior and concealed larval habitat. Potential components of an integrated pest management program for S. lineatus were investigated near Lethbridge and Vauxhall, Alberta over three years. Cage studies indicated that larval feeding is more damaging than adult feeding but that larval populations are not dependent on adult weevil density. In open plot experiments, thiamethoxam-treated plants experienced significantly less foliar feeding damage than plants receiving no insecticide treatment but no consistent effects on yield were observed for any plot treatment over six site-years. Rhizobium inoculation had a synergistic interaction with thiamethoxam. Laboratory trials showed that Bembidion quadrimaculatum L. (Coleoptera: Carabidae) consumed S. lineatus eggs. Seed treatment with thiamethoxam and Rhizobium inoculant, and egg predation should be included in an integrated pest management program for S. lineatus. / Plant Science

Green manure crops are critical to maintaining soil fertility in organic cropping systems. However, little research has been conducted to address their contribution to weed control. Indianhead black lentil (Lens culinaris Medikus), AC Green Fix chickling vetch (Lathyrus sativus L.), and Trapper field pea (Pisum sativum L.) are legumes developed for use as annual green manure crops in the Northern Great Plains. Currently, no plant population density recommendations exist for these three species when grown as green manure crops under weedy conditions. The objective of this research was to determine the yield-density response of these three species under weedy and weedy-free conditions and to develop plant population density recommendations for use as annual green manure crops. Each species was grown at five plant population densities (10, 24, 64, 160, and 400 plants m-2) with weedy and weed-free treatments. Wild oat (Avena fatua L.) and wild mustard (Brassica kaber (D.C.) L.C. Wheeler) were planted in weedy treatments to supplement the natural weed community. Biomass samples and soil moisture measurements were taken at early bud and full bloom to simulate when these crops would be terminated. Biomass samples from the early bud stage were analysed for total nitrogen content. Green manure biomass production for all species was lower under weedy conditions. Weed biomass in weedy treatments decreased with increasing green manure plant population density for all species. Trapper field pea was the most competitive crop while Indianhead black lentil was the least competitive. Although total plot biomass differed among species and green manure crop density, changes in soil moisture levels were not greatly affected. No significant difference in total nitrogen concentration was found among green manure species. Differences in total nitrogen accumulation occurred because of differences in biomass production. Marginal cost analysis based on green manure seed costs and their nitrogen contribution to the value of subsequent wheat crop yield were used to determine optimum plant population densities. Under weedy conditions field pea and black lentil should be planted at densities of 49-78 and 223-300 plants m-2, respectively. Under weed-free conditions plant population densities for field pea and black lentil could be reduced to 45-60 and 184-223 plants m-2, respectively. No profitable plant population density was determined for chickling vetch when assuming a lower nitrogen contribution under both weedy and weed-free conditions. However, when assuming a higher nitrogen contribution, a profitable plant population density for chickling vetch of 24 plants m-2 was determined under weedy conditions and 32 plants m-2 under weed-free conditions.

Green manure crops are critical to maintaining soil fertility in organic cropping systems. However, little research has been conducted to address their contribution to weed control. Indianhead black lentil (Lens culinaris Medikus), AC Green Fix chickling vetch (Lathyrus sativus L.), and Trapper field pea (Pisum sativum L.) are legumes developed for use as annual green manure crops in the Northern Great Plains. Currently, no plant population density recommendations exist for these three species when grown as green manure crops under weedy conditions. The objective of this research was to determine the yield-density response of these three species under weedy and weedy-free conditions and to develop plant population density recommendations for use as annual green manure crops. Each species was grown at five plant population densities (10, 24, 64, 160, and 400 plants m-2) with weedy and weed-free treatments. Wild oat (Avena fatua L.) and wild mustard (Brassica kaber (D.C.) L.C. Wheeler) were planted in weedy treatments to supplement the natural weed community. Biomass samples and soil moisture measurements were taken at early bud and full bloom to simulate when these crops would be terminated. Biomass samples from the early bud stage were analysed for total nitrogen content. Green manure biomass production for all species was lower under weedy conditions. Weed biomass in weedy treatments decreased with increasing green manure plant population density for all species. Trapper field pea was the most competitive crop while Indianhead black lentil was the least competitive. Although total plot biomass differed among species and green manure crop density, changes in soil moisture levels were not greatly affected. No significant difference in total nitrogen concentration was found among green manure species. Differences in total nitrogen accumulation occurred because of differences in biomass production. Marginal cost analysis based on green manure seed costs and their nitrogen contribution to the value of subsequent wheat crop yield were used to determine optimum plant population densities. Under weedy conditions field pea and black lentil should be planted at densities of 49-78 and 223-300 plants m-2, respectively. Under weed-free conditions plant population densities for field pea and black lentil could be reduced to 45-60 and 184-223 plants m-2, respectively. No profitable plant population density was determined for chickling vetch when assuming a lower nitrogen contribution under both weedy and weed-free conditions. However, when assuming a higher nitrogen contribution, a profitable plant population density for chickling vetch of 24 plants m-2 was determined under weedy conditions and 32 plants m-2 under weed-free conditions.

<p>Заснивање вишегодишњих легуминоза у пролећном року сетве често је праћено интензивнијим развојем корова и смањеним приносом. Ово је случај и приликом гајења еспарзете (Onobrychis viciifolia Scop.), која се сматра потенцијалном заменом за луцерку. Здружена сетва, односно гајење две или више врста на једном пољу током одређеног периода, може се користити као начин заснивања ове вишегодишње легуминозе. Осим традиционалног здруживања легуминозе и стрнине, као надусев може се користити и сточни грашак (Pisum sativum L.), због своје краће вегетације и смањеног конкурентског утицаја на подусев. Циљ рада је био да се утврди да ли је сточни грашак погодан за заснивање еспарзете у здруженој сетви, као и да се утврди одговарајућа сорта и густина грашка која омогућава најбољи принос и утицај на подусев. Двофакторијални оглед постављен је на експерименталном пољу Института за ратарство и повртарство, Нови Сад, током 2010-2014. године и укључио је две сорте грашка различитих морфолошких особина (Језеро-афила тип листа, Јавор-редуковане лиске) сејане у три густине. Као контролне варијанте коришћене су чист усев еспарзете и здружена сетва еспарзете и овса. Оглед је засниван у четворогодишњем периоду и испитивања су вршена у години заснивања и првом откосу у години искоришћавања.<br />Утврђено је да су временски услови значајно утицали на остварен принос у току истраживања. Сточни грашак као надусев имао је повољније деловање на еспарзету и њен развој након сваког откоса, с тим да је присуство надусева у другој години живота имало минималан утицај на остварени принос. Принос суве материје у првом откосу био је већи са сортом Језеро. Између приноса са 60 и 90 биљака грашка по m2 разлика у приносу није била статистички значајна, што је посебно значајно са економског аспекта производње. Резултати су показали да је највећи укупан принос суве материје имала еспарзета са овсем, услед значајног са повећањем густине смеше. Резултати су показали да је здружена сетва две легуминозе утицала на већи садржај минералног азота у земљишту након првог откоса. Присуство и густина надусева у првом откосу утицали су на интензивније коришћење влаге у земљишту, док је у наредним мерењима утицај фактора на количину воде у слоју до 60 cm био минималан.</p><p>Значај заснивања еспарзете у здруженој сетви са грашком показан је и кроз садржај сирових протеина, који је био већи у здруженој сетви у односу на чист усев еспарзете. При томе, сварљивост крме је била већа, с обзиром на то да је смеша еспарзете и грашка имала мањи удео NDF-а и ADF-а у односу на контроле.</p><p>Остварени резултати показују да се еспарзета може успешно заснивати у здруженој сетви са сточним грашком чиме се обезбеђује стабилан принос првог откоса високог квалитета, без негативног утицаја на регенерацију еспарзете и принос у наредним откосима. Резултати указују да је здружена сетва поуздан и еколошки начин заснивања еспарзете, који пружа могућност да ова врста буде заступљенија у пракси.удела првог откоса у укупном приносу. Удео корова у здруженој сетви био је мањи у односу на чист усев еспарзете. Сорта Језеро у просеку имала је већу компетативну способност, док је у просеку за обе сорте најмањи удео корова утврђен у смеши са 60 биљака грашка.<br />Морфолошки различите сорте грашка нису довеле до статистички значајних разлика у вредностима индекса лисне површине еспарзете, али се вредност овог параметра смањивала са повећањем густине надусева. Садржај фотосинтетичких пигмената био је већи на третманима са здруженом сетвом, али је и значајно зависио од временских услова. Биолошка активност земљишта била је већа у здруженој сетви у односу на чист усев еспарзете. Бројност азотофиксатора била је већа при мањем присуству надусева, док се укупан број бактерија и гљива<br />повећавао</p> / <p>Zasnivanje višegodišnjih leguminoza u prolećnom roku setve često je praćeno intenzivnijim razvojem korova i smanjenim prinosom. Ovo je slučaj i prilikom gajenja esparzete (Onobrychis viciifolia Scop.), koja se smatra potencijalnom zamenom za lucerku. Združena setva, odnosno gajenje dve ili više vrsta na jednom polju tokom određenog perioda, može se koristiti kao način zasnivanja ove višegodišnje leguminoze. Osim tradicionalnog združivanja leguminoze i strnine, kao nadusev može se koristiti i stočni grašak (Pisum sativum L.), zbog svoje kraće vegetacije i smanjenog konkurentskog uticaja na podusev. Cilj rada je bio da se utvrdi da li je stočni grašak pogodan za zasnivanje esparzete u združenoj setvi, kao i da se utvrdi odgovarajuća sorta i gustina graška koja omogućava najbolji prinos i uticaj na podusev. Dvofaktorijalni ogled postavljen je na eksperimentalnom polju Instituta za ratarstvo i povrtarstvo, Novi Sad, tokom 2010-2014. godine i uključio je dve sorte graška različitih morfoloških osobina (Jezero-afila tip lista, Javor-redukovane liske) sejane u tri gustine. Kao kontrolne varijante korišćene su čist usev esparzete i združena setva esparzete i ovsa. Ogled je zasnivan u četvorogodišnjem periodu i ispitivanja su vršena u godini zasnivanja i prvom otkosu u godini iskorišćavanja.<br />Utvrđeno je da su vremenski uslovi značajno uticali na ostvaren prinos u toku istraživanja. Stočni grašak kao nadusev imao je povoljnije delovanje na esparzetu i njen razvoj nakon svakog otkosa, s tim da je prisustvo naduseva u drugoj godini života imalo minimalan uticaj na ostvareni prinos. Prinos suve materije u prvom otkosu bio je veći sa sortom Jezero. Između prinosa sa 60 i 90 biljaka graška po m2 razlika u prinosu nije bila statistički značajna, što je posebno značajno sa ekonomskog aspekta proizvodnje. Rezultati su pokazali da je najveći ukupan prinos suve materije imala esparzeta sa ovsem, usled značajnog sa povećanjem gustine smeše. Rezultati su pokazali da je združena setva dve leguminoze uticala na veći sadržaj mineralnog azota u zemljištu nakon prvog otkosa. Prisustvo i gustina naduseva u prvom otkosu uticali su na intenzivnije korišćenje vlage u zemljištu, dok je u narednim merenjima uticaj faktora na količinu vode u sloju do 60 cm bio minimalan.</p><p>Značaj zasnivanja esparzete u združenoj setvi sa graškom pokazan je i kroz sadržaj sirovih proteina, koji je bio veći u združenoj setvi u odnosu na čist usev esparzete. Pri tome, svarljivost krme je bila veća, s obzirom na to da je smeša esparzete i graška imala manji udeo NDF-a i ADF-a u odnosu na kontrole.</p><p>Ostvareni rezultati pokazuju da se esparzeta može uspešno zasnivati u združenoj setvi sa stočnim graškom čime se obezbeđuje stabilan prinos prvog otkosa visokog kvaliteta, bez negativnog uticaja na regeneraciju esparzete i prinos u narednim otkosima. Rezultati ukazuju da je združena setva pouzdan i ekološki način zasnivanja esparzete, koji pruža mogućnost da ova vrsta bude zastupljenija u praksi.udela prvog otkosa u ukupnom prinosu. Udeo korova u združenoj setvi bio je manji u odnosu na čist usev esparzete. Sorta Jezero u proseku imala je veću kompetativnu sposobnost, dok je u proseku za obe sorte najmanji udeo korova utvrđen u smeši sa 60 biljaka graška.<br />Morfološki različite sorte graška nisu dovele do statistički značajnih razlika u vrednostima indeksa lisne površine esparzete, ali se vrednost ovog parametra smanjivala sa povećanjem gustine naduseva. Sadržaj fotosintetičkih pigmenata bio je veći na tretmanima sa združenom setvom, ali je i značajno zavisio od vremenskih uslova. Biološka aktivnost zemljišta bila je veća u združenoj setvi u odnosu na čist usev esparzete. Brojnost azotofiksatora bila je veća pri manjem prisustvu naduseva, dok se ukupan broj bakterija i gljiva<br />povećavao</p> / <p>The establishment of perennial legumes in the spring is often followed by intensive weeds infestation and reduced yield. This is also the case when growing sainfoin (Onobrychis viciifolia Scop.) which is considered a potential substitute for alfalfa (Medicago sativa L.). Intercropping or growing two or more species in the same field during a certain period can be used for establishing this perennial legume. A field pea (Pisum sativum L.) has a potential to be used as companion crop due to a short growing season and reduced competing impact. The aim of this research was to determine the suitability of field pea as a companion crop for sainfoin establishment and to determine the appropriate cultivar and pea density that provides the best yield and impact on undersown crop. A two-factorial trial was set up in the experimental field of the Institute of Field and Vegetable Crops, Novi Sad, during 2010-2014. The experiment included two morphologically different pea cultivars (Jezero-afila leaf type and Javor-reduced leaflet) and three pea densities. The sainfoin pure stand and a mixture with oat were used as control treatments. The trial included four sowing years and the analysis was performed in the establishment years and in the first cut in the full harvest year.<br />The weather conditions significantly influenced obtained yield. Field pea as a companion crop had a better impact on sainfoin development in the establishment year, while in subsequent year companion crops had minimal impact on sainfoin yield. Concerning pea cultivars, a higher dry matter yield was obtained with cultivar Jezero. It was concluded, there were no significant differences between obtained yield with 60 and 90 pea plants per m2 which have importance from the economic aspect. The results showed that the highest annual yield had a mixture of sainfoin and oat, due to a significant share of the first yield. The weed proportion was lower in intercropping compared to the sainfoin pure stand. The cultivar Jezero and a density of 60 pea plants per m2 were more competitive to weeds.<br />Morphologically different pea cultivars did not significantly affect leaf area index of sainfoin. However, its value decreased with the increase of pea density in the stand. Intercropping and weather conditions had a significant impact on pigment content in sainfoin leaves. The examined soil biological activity was higher in intercropping treatments. The number of nitrogen fixation bacteria increased with a decreased number of pea plants, while the number of total bacteria and fungi increased with increasing pea density. The intercropping of the legumes influenced the higher content of mineral nitrogen in the soil, but also the more intensify use of soil moisture. The positive effect of intercropping of two legumes was demonstrated by the obtained higher content of crude protein with a lower proportion of digestibility parameters - NDF and ADF compared to both control treatments.<br />The obtained results show that sainfoin can be successfully established with field pea in intercropping, which ensures the stable and high-quality yield of the first cut, without negative esainfoin re-growth and yield in subsequent cuts. Thus, intercropping can be considered as a reliable and ecological practice for sainfoin establishment, which provides the possibility for increasing production of this species.</p>

[Truncated abstract] Field pea (Pisum sativum) has many benefits when included in the crop rotation system in broadacre grain farming. These benefits include a disease break and improved weed control for cereals and less dependence on nitrogenous fertilisers due to the leguminous nature of pea. Currently, field pea adoption in Australia is low because the crop is susceptible to the fungal disease `black spot’ (Mycosphaerella pinodes) and has low stem strength and a lodged canopy. Black spot causes yield losses averaging 10-15% per year. Lodging results in difficult and costly harvesting, increased disease pressure and increased wind erosion from exposed soil surface when stems break at the basal nodes. This project aimed to address these problems through breeding, and through the application of quantitative genetics theory to a recurrent selection program. A quantitative measurement of relative stem strength was developed which could be used effectively in the field on single plants. Accurate laboratory measurements of stem strength were closely correlated with the field measure of compressed stem thickness in the basal node region. A diallel analysis of stem strength of the progeny of crosses among a range of pea lines with different values of compressed stem thickness concluded that the genetic control of stem strength was additive, with no maternal inheritance or dominance or epistasis effects.

Herbicides have become a key component in modern agricultural production. Meanwhile, there is a concern that some herbicides persist past the growing season of the treated crop, and negatively influence the production of the subsequently planted crops. Amongst various herbicides used in western Canada, acetohydroxyacid synthase (AHAS)-inhibiting herbicides warrant special attention given their residual properties and acute plant toxicity at low concentrations in soil. Soil residual AHAS inhibitors have the potential to influence both leguminous host plants and their bacterial symbiotic partners; consequently, the use of an AHAS inhibitor in a given year can negatively influence the inoculation success and grain yield of legumes cropped in the following year. <p>The present thesis project focused on one of the AHAS inhibiting herbicides (flucarbazone) and studied its potential for carryover injury and negative influence on the success of inoculation in field pea. A series of growth chamber and field experiments were conducted to test the following null hypothesis: the presence of residual flucarbazone in soil does not affect nodulation of field pea by inoculum rhizobia. <p>A growth chamber experiment clearly demonstrated the susceptibility of field pea to the presence of flucarbazone in soil where the lowest concentration of flucarbazone amendment (5 ìg kg1) significantly reduced the crop growth. In contrast, a field study failed to reveal any negative effects of flucarbazone use on crop growth and N2 fixation. <p>It was concluded that if the weather and soil conditions favour decomposition of flucarbazone as described in the present study, flucarbazone applied at the recommended field rate will not persist into the following season at high enough concentrations to negatively influence field pea growth, grain yields, and inoculation success. To ensure safety of rotational crops, it is important to strictly adhere to the herbicide application guidelines. Additionally, producers are cautioned to be particularly aware of the environmental and soil conditions that may reduce the rate of herbicide degradation.

Herbicides have become a key component in modern agricultural production. Meanwhile, there is a concern that some herbicides persist past the growing season of the treated crop, and negatively influence the production of the subsequently planted crops. Amongst various herbicides used in western Canada, acetohydroxyacid synthase (AHAS)-inhibiting herbicides warrant special attention given their residual properties and acute plant toxicity at low concentrations in soil. Soil residual AHAS inhibitors have the potential to influence both leguminous host plants and their bacterial symbiotic partners; consequently, the use of an AHAS inhibitor in a given year can negatively influence the inoculation success and grain yield of legumes cropped in the following year. <p>The present thesis project focused on one of the AHAS inhibiting herbicides (flucarbazone) and studied its potential for carryover injury and negative influence on the success of inoculation in field pea. A series of growth chamber and field experiments were conducted to test the following null hypothesis: the presence of residual flucarbazone in soil does not affect nodulation of field pea by inoculum rhizobia. <p>A growth chamber experiment clearly demonstrated the susceptibility of field pea to the presence of flucarbazone in soil where the lowest concentration of flucarbazone amendment (5 ìg kg1) significantly reduced the crop growth. In contrast, a field study failed to reveal any negative effects of flucarbazone use on crop growth and N2 fixation. <p>It was concluded that if the weather and soil conditions favour decomposition of flucarbazone as described in the present study, flucarbazone applied at the recommended field rate will not persist into the following season at high enough concentrations to negatively influence field pea growth, grain yields, and inoculation success. To ensure safety of rotational crops, it is important to strictly adhere to the herbicide application guidelines. Additionally, producers are cautioned to be particularly aware of the environmental and soil conditions that may reduce the rate of herbicide degradation.