Inter-Relationships Between Yield And Yield Attributes Of Potato Grown Under Supra-Optimal Ambient Temperatures

Forty eight potato genotypes were evaluated in Saminaka (Lat. 100 27’N and Long 40E, Mean Min. Temp 25oC, Mean Max Temp 31.5oC) during the rainy season of 1999 and 2000 to determine the inter-relationship between yield and some important agronomic traits in the potato grown under high ambient temperatures. The genotypes were laid out in a randomized complete block design with three replications. The genotypes exhibited highly significant variability (

Crop Adaptation to Elevated CO2 and Temperature

This book contains a collection of recent peer-reviewed articles on the topic "Crop Adaptation to Elevated CO2 and Temperature" published in Plants. Topics range from meta-analyses of crop responses, to descriptions and results of large-scale screening efforts, to molecular studies of changes in gene expression related to fruit quality

Effect of curing conditions and harvesting stage of maturity on Ethiopian onion bulb drying properties

The study was conducted to investigate the impact of curing conditions and harvesting stageson the drying quality of onion bulbs. The onion bulbs (Bombay Red cultivar) were harvested at three harvesting stages (early, optimum, and late maturity) and cured at three different temperatures (30, 40 and 50 oC) and relative humidity (30, 50 and 70%). The results revealed that curing temperature, RH, and maturity stage had significant effects on all measuredattributesexcept total soluble solids

22nd EAPR Triennial conference, Oslo, Norway, July 7-12, 2024. Book of abstracts

Abstracts from The 22nd Triennial conference of EAPR in Oslo 7-12 July 2024. The organizer of the conference was the Norwegian Institute of Bioeconomy Research (NIBIO).22nd EAPR Triennial conference, Oslo, Norway, July 7-12, 2024. Book of abstractspublishedVersio

Herbaceous Field Crops Cultivation

Herbaceous field crops include several hundred plant species worldly widespread for different end-uses, from food to no-food applications. Among them are included cereals, grain legumes, sugar beet, potato, cotton, tobacco, sunflower, safflower, rape, flax, soybean, alfalfa, clover spp. and other fodder crops, but only 15–20 species play a relevant role for the worldly global economy. Nowadays, to meet the food demand of the ever-increasing world population in a scenario of decreased arable lands, the development of holistic agricultural management approaches to boost contemporaneously yield and quality of herbaceous field crops is essential. Accordingly, this book represents an up-to-date collection of the current understanding of the impact of several agricultural management factors (i.e., genetic selection, planting density and arrangement, fertilization, irrigation, weed control and harvest time) on the yield and qualitative performances of 11 field crops (wheat, cardoon, potato, clary sage, basil, sugarcane, canola, cotton, tomato, lettuce and hemp). On the whole, the topics covered in this book will ensure students and academic readers, such as plant physiologists, environmental scientists, biotechnologists, botanists, soil chemists and agronomists, to get the information about the recent research advances on the eco-sustainable management cultivation of herbaceous field crops, with a particular focus on varietal development, soil nutrient and water management, weed control, etc

Growth and yield of red raspberries cultivated under open field condition vs. high tunnel or rain shelter in the northern canadian climate

La culture sous abris avec des infrastructures de type grands tunnels est une nouvelle technologie permettant d’améliorer la production de framboises rouges sous des climats nordiques. L’objectif principal de ce projet de doctorat était d'étudier les performances de ces technologies (grands tunnels vs. abris parapluie de type Voen, en comparaison à la culture en plein champ) et leur effets sur le microclimat, la photosynthèse, la croissance des plantes et le rendement en fruits pour les deux types de framboisiers non-remontants et remontants (Rubus idaeus, L.). Puisque les pratiques culturales doivent être adaptées aux différents environnements de culture, la taille d'été (pour le cultivar non-remontant), l’optimisation de la densité des tiges (pour le cultivar remontant) et l’utilisation de bâches réfléchissantes (pour les deux types des framboisiers) ont été étudiées sous grands tunnels, abris Voen vs. en plein champ. Les plants cultivés sous grands tunnels produisent en moyenne 1,2 et 1,5 fois le rendement en fruits commercialisables que ceux cultivés sous abri Voen pour le cv. non-remontant ‘Jeanne d'Orléans’ et le cv. remontant ‘Polka’, respectivement. Comparativement aux framboisiers cultivés aux champs, le rendement en fruits des plants sous grands tunnels était plus du double pour le cv. ‘Jeanne d’Orléans’ et près du triple pour le cv. ‘Polka’. L’utilisation de bâches réfléchissantes a entrainé un gain significatif sur le rendement en fruits de 12% pour le cv. ‘Jeanne d’Orléans’ et de 17% pour le cv. ‘Polka’. La taille des premières ou deuxièmes pousses a significativement amélioré le rendement en fruits du cv. ‘Jeanne d'Orléans’ de 26% en moyenne par rapport aux framboisiers non taillés. Des augmentations significatives du rendement en fruits de 43% et 71% du cv. ‘Polka’ ont été mesurées avec l’accroissement de la densité à 4 et 6 tiges par pot respectivement, comparativement à deux tiges par pot. Au cours de la période de fructification du cv. ‘Jeanne d'Orléans’, les bâches réfléchissantes ont augmenté significativement la densité de flux photonique photosynthétique (DFPP) réfléchie à la canopée inférieure de 80% en plein champ et de 60% sous grands tunnels, comparativement à seulement 14% sous abri Voen. Durant la saison de fructification du cv. ‘Polka’, un effet positif de bâches sur la lumière réfléchie (jusqu’à 42%) a été mesuré seulement en plein champ. Dans tous les cas, les bâches réfléchissantes n’ont présenté aucun effet significatif sur la DFPP incidente foliaire totale et la photosynthèse. Pour le cv. ‘Jeanne d'Orléans’, la DFPP incidente sur la feuille a été atténuée d’environ 46% sous le deux types de revêtement par rapport au plein champ. Par conséquent, la photosynthèse a été réduite en moyenne de 43% sous grands tunnels et de 17% sous abris Voen. Des effets similaires ont été mesurés pour la DFPP incidente et la photosynthèse avec le cv. Polka. En dépit du taux de photosynthèse des feuilles individuelles systématiquement inférieur à ceux mesurés pour les plants cultivés aux champs, la photosynthèse de la plante entière sous grands tunnels était de 51% supérieure à celle observée au champ pour le cv. ‘Jeanne d’Orléans’, et 46% plus élevée pour le cv. ‘Polka’. Ces résultats s’expliquent par une plus grande (près du double) surface foliaire pour les plants cultivés sous tunnels, qui a compensé pour le plus faible taux de photosynthèse par unité de surface foliaire. Les températures supra-optimales des feuilles mesurées sous grands tunnels (6.6°C plus élevé en moyenne que dans le champ), ainsi que l’atténuation de la DFPP incidente (env. 43%) par les revêtements de tunnels ont contribué à réduire le taux de photosynthèse par unité de surface foliaire. La photosynthèse de la canopée entière était étroitement corrélée avec le rendement en fruits pour les deux types de framboisiers rouges cultivés sous grands tunnels ou en plein champ.Protected culture such as high tunnels is a new technology to improve red raspberry crop production under Northern climates as found in Quebec, Canada. The main objective of this Ph.D. research was to assess the performance of high tunnels vs. Voen shelters, a novel umbrella-shaped cover structure, in comparison to open field cultivation, in terms of microclimate, photosynthetic performance, plant growth, and fruit yield for both floricane- and primocane-fruiting types of red raspberries (Rubus idaeus, L.). As cultural management practices need to be tailored to the different modified growing environments, relevant practices like summer pruning (for floricane-fruiting cultivar), cane density optimization (for primocane-fruiting cultivar) and reflective mulch (for both fruiting types) were tested under high tunnel and Voen shelter vs. open field. Plants grown under high tunnel produced on average 1.2 and 1.5 times more marketable fruit yield than under Voen shelter for floricane-fruiting cv. ‘Jeanne d’Orléans’ and primocane-fruiting cv. ‘Polka’, respectively. Compared to plants grown in open field, the fruit yield of high tunnel-grown plants was more than double for cv. ‘Jeanne d’Orléans’ and almost three times higher for cv. ‘Polka’. The use of reflective mulch had a significant positive effect on fruit yield, namely 12% for cv. ‘Jeanne d’Orléans’ and 17% for cv. ‘Polka’. Pruning the first or second flush of stems from the rhizome significantly improved fruit yield of cv. ‘Jeanne d’Orléans’ by 26% on average compared to unpruned plants. As cane density increased, the fruit yield of cv. ‘Polka’ increased significantly, namely by 43% and 71% for a cane density of 4 and 6 canes per pot, respectively, as compared to the standard lower cane density of 2 canes per pot. During the fruiting period of cv. ‘Jeanne d’Orléans’, reflective ground cover significantly increased the photosynthetic photon flux density (PPFD) reflected to the lower canopy by 80% in open field and 60% under high tunnel, compared to only 14% under Voen shelter. During the fruiting season of cv. ‘Polka’, a positive reflective mulch effect on the reflected light (up to 42%) was only found in open field. In all cases, ground cover had no significant effect on the total leaf PPFD and photosynthesis under any growing conditions. For cv. ‘Jeanne d’Orléans’, the leaf PPFD was attenuated by approx. 46% under both types of protective covering compared to open field. Correspondingly, photosynthesis was on average reduced by 43% under high tunnel and by 17% under Voen shelter. Cultivar ‘Polka’ plants shared a similar growing condition effects on leaf PPFD and photosynthesis. Despite the fact that lower individual leaf photosynthetic rates were consistently measured in tunnel-grown plants, once leaf-level photosynthesis was scaled up to the whole canopy, the photosynthetic production of tunnel-grown plants was found to be 51% higher than that observed in open field for cv. ‘Jeanne d’Orléans’, and 46% higher for cv. ‘Polka’. This was explained by the greater (nearly twice) leaf area of tunnel-grown plants, which compensated for their lower photosynthetic rate per unit leaf area, the latter being caused by the supra-optimal leaf temperatures found under high tunnel (6.6°C higher on average than in open field) as well as the attenuation of the leaf PPFD (approx. 43%) by the tunnel coverings. Whole-canopy photosynthesis was positively correlated with fruit yield for both fruiting types of red raspberry, whether cultivated under high tunnel or in open field

Modelling rice and wheat response to rising carbon dioxide concentration

Better crop photosynthetic efficiency is important for enhancing field crop production. The improvement in the photosynthetic efficiency of a crop depends on its efficiency in the usage of resources, including CO2, water, nitrogen (N) and radiation. However, prolonged exposure to elevated carbon dioxide concentration (e[CO2]) and, a short supply of other resources may lead to a decline in photosynthesis – a process referred to as ‘acclimation.’ Studies have demonstrated photosynthetic acclimation at the flag leaf level in a variety of crops. However, progress is limited in addressing the gaps in knowledge about the link between leaf-level acclimation phenomena and canopy level performance, which is influenced by different growth and development processes and abiotic factors. Therefore, there is a need for crop models capable of accurately extrapolating the leaf-level response to canopy level, to understand the overall impact of changes in photosynthesis at the biochemical level and its consequence on crop growth, development and productivity. In this regard, the research described in this thesis is founded on the hypotheses, that i) primary plant responses, photosynthesis and stomatal conductance to e[CO2] are regulated by the interaction of different environmental variables ii) photosynthesis acclimation, on prolonged exposure to e[CO2], is associated with a change in the leaf ribulose-1,5-bisphosphate carboxylase oxygenase (RuBisCO) and N concentration and, iii) photosynthetic acclimation can be better captured when biochemical parameters are included in the crop models like APSIM which is based on the concepts of cross-scale modelling, facilitating crop growth and development. A meta-analysis of the studies reported in the literature was conducted to evaluate the impact of e[CO2] on two major physiological processes, photosynthesis and stomatal conductance in two primary functional groups of plants – C3 and C4. Within C3 and C4 crops, more specific groups including legumes, non-legumes, flowers, trees, shrubs and grasses were examined to evaluate their respective responses to e[CO2] under different abiotic stresses. The abiotic factors like water, N and temperature were found to be critical in determining the photosynthetic efficiency and thus, the biomass of plants. Understanding the role of abiotic factors, particularly N, in the photosynthesis under continuous exposure to e[CO2] is essential to predict the crop response to the possibility of an e[CO2] in the earth’s atmosphere, in the future. In this study, rice response to e[CO2] was estimated using a system dynamics modelling tool, STELLA. An analytical modelling framework embedding leaf-level crop system including RuBisCO and N dynamics and crop growth processes are developed using the STELLA software. The secondary data on rice from a growth chamber experiment was utilised to validate the model. The simulated response strongly supported the occurrence of photosynthetic acclimation at both growth and biochemical levels, under different e[CO2], at different levels of N supply. Further, this study evaluated photosynthesis, in-depth, in determining e[CO2]-induced acclimation and thus, growth. Two major parameters that were used for estimations are the maximum carboxylation capacity (Vc.max) and the electron transport capacity (Jmax). Data from the Australian Grains Free-Air CO2 Enrichment (AGFACE), Horsham, Victoria, Australia were analyzed and modelled to determine the changes in the photosynthetic response of another C3 crop, wheat, to e[CO2]. The Agriculture Production System Simulator coupled with the diurnal canopy photosynthesisstomatal conductance model (hereafter referred to as APSIMDCP) was used to validate the APSIMDCP model and evaluate the range of parameters associated with photosynthetic acclimation under e[CO2]. It was established that APSIMDCP could adequately link the biochemical and crop level responses, to enable extending the leaf level model to the canopy level. Further, it successfully simulated the photosynthetic acclimation responses to e[CO2] for different wheat cultivars which were characterized by reduction of Vc.max, Jmax and leaf N concentration. However, all cultivars were not equally responsive to the e[CO2], with some showing no response at all and, others showing responses of varying magnitude, illustrating genotypic variation in this trait. In summary, this study investigated the impact of e[CO2] on variation in photosynthesis in rice and wheat at different physiological stages of growth to predict the biomass and yield responses accurately