Volume 3 Special Issue 1 2010
Plant science and biotechnology in South America: Focus on Argentina I
How to reference: Caviglia OP, Andrade FH (2010) Sustainable Intensification of Agriculture in the Argentinean Pampas: Capture and Use Efficiency of Environmental Resources. In: Di Benedetto A (Ed) Plant science and biotechnology in South America: Focus on Argentina I. The Americas Journal of Plant Science and Biotechnology 3 (Special Issue 1), 1-8
Adalberto Di Benedetto
Universidad de Buenos Aires and Facultad de Ciencias Agrarias
Universidad de Mar del Plata, Argentina
CONTENTS AND ABSTRACTS
Octavio P. Caviglia, Fernando H. Andrade (Argentina) Sustainable Intensification of Agriculture in the Argentinean Pampas: Capture and Use Efficiency of Environmental Resources (pp 1-8)
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Invited Review: Future human needs for food and fiber should be fulfilled mainly through the agricultural intensification on the actual cultivated land, pursuing an economically viable, socially acceptable and environmentally sustainable system. The objectives of this review are to: i) briefly describe the current cropping systems of the Argentinean Pampas, ii) discuss the reliability of cropping system intensification practices and to, iii) analyze the extent of the improvement in the use of water and solar radiation by incorporating cropping system intensification practices in the Argentinean Pampas. Current cropping systems in the Argentinean Pampas largely rely on summer crops, including soybean as the most widespread crop. The unbalanced cropping sequence of the Pampas has several aspects that threat their sustainability and efficiency. Sustainable intensification of agriculture in the Argentinean Pampas rely on a more intense use of cultivated land and environmental resources, such as rainfall and solar radiation, using an appropriate set of agronomic practices aiming to higher grain production focused on environmental concern. Since there is little scope for further increase in resource capture and use in the typically well managed single crops of the Pampas, the improvements will be strongly associated with higher levels of intensification, cultivating crops more frequently than before, and using the available resources during the winter season. Increases in water and radiation use efficiency would, however, be more related to the inclusion of more efficient crops involved in the sequence. Owing the north to south decreasing gradient of the length of growing season in the Argentinean Pampas, the choice of the more adequate cropping strategy to sequence intensification can be quite different.
Javier E. Gyenge, María Elena Fernández, Verónica Rusch, Mauro M. Sarasola, Tomás M. Schlichter (Argentina) Towards Sustainable Forestry Development in Patagonia: Truths and Myths of Environmental Impacts of Plantations with Fast-Growing Conifers (pp 9-22)
Invited Review: In NW Patagonia region, Argentina, South-America, there are about 70,000 ha of planted forests replacing from native forests to grasslands with different degrees of deterioration due to previous land use. Although forestry development has been quite slow in this region compared to other regions of the country, it is expected that this activity will be increasing in the future due to provincial and national government policies of forestry incentives. In general, only scarce information is available about the environmental impact of forestation in the region. Our objective was to bring together the knowledge about the changes in biodiversity, water cycle and water resources, soil characteristics and the risk of invasion of introduced exotic fast-growing coniferous species on native ecosystems. The analyses revealed that the greatest changes in biodiversity, water consumption and invasion risk occurred when the introduction of trees was in grasslands compared to forest or shrublands. However, from our results we can conclude that, at the current developmental stage of forestry activity in Patagonia, the negative environmental impact is very low or even nil, with the positive impacts –economic and social- possibly being higher and leading to a more positive balance as a whole. However, we recognize that potential negative impacts, whose magnitude will depend on several aspects discussed in the paper, could increase in the future in relation to the expansion of the forested areas. With the available information we can then formulate prescriptions and management strategies for exotic systems, in order to guarantee the long term sustainability of the activity. In this regard, we have the opportunity of developing a sustainable production activity from the very beginning.
Olga Marcellán, Elsa Camadro, Ana Clara Pontaroli (Argentina) Contributions of Biotechnology to Asparagus Breeding in Argentina (pp 23-30)
Invited Review: Garden asparagus (Asparagus officinalis L.) is an economically important horticultural crop, susceptible to pathogenic soil fungi of the genus Fusarium. These fungi cause stem, crown and root rot, a major disease all over the world that is difficult to control by the use of chemicals and cultural practices. The development of resistant/tolerant cultivars appears to be the best alternative for control; however, the asparagus-Fusarium pathosystem is complex and advances in this regard have not been very successful. The species is perennial and dioecious, which hinders the breeding process, but it can be asexually and sexually reproduced and in vitro manipulated. In Argentina, imported open-pollinated cultivars and F1 and F2 clonal hybrids are grown, which are susceptible to Fusarium and not necessarily adapted to local conditions. In 1992, an asparagus breeding program was started in Balcarce, in collaboration with another national research group, to (a) generate adapted and good yielding cultivars and (b) explore potential sources of Fusarium resistance. Various biotechnologies were used in an attempt to generate and/or introduce genetic variability for the trait (gametophyte selection, in vitro selection of plants and calluses, interspecific hybridization followed by in vitro ovule culture) and to clone elite genotypes (micropropagation and somatic embryogenesis) to produce clonal hybrids. The principal results of the application of these biotechnologies are summarized in this review.
Pablo Marinangeli, Nestor Curvetto (Argentina) Improvement of in Vitro Plant Regeneration for Genetic Transformation of Argentinean Onion Varieties (pp 31-37)
Invited Review: Incorporation of certain genetic traits into plants depends on the existence of an appropriate transformation protocol for the species. The development of such a biotechnological approach to insert new attributes in onion (Allium cepa L.) did not exist until a few years ago. In spite of this achievement, studies aimed at the optimization of the transformation protocol adjusted for local conditions, including genotypes, are still needed. Indeed, genotypes are of extreme importance in the case of onion since they exhibit a wide variable in vitro behavior. On the other hand, the preference of both producers and consumers from Argentina and importer countries is on distinctive local cultivars. Thus, it is of utmost importance to study and adjust the conditions to establish a protocol leading to stable genetic transformation of local onion cultivars. The main constraint to achieving this goal is the establishment of an efficient system for in vitro plant regeneration.
Marina Sisterna, Lía Ronco, Claudio Voget, Mariana Marasas, Esteban Abbona, María Romero, Jorge Daniele, Silvina Artaza, Joaquín Otero, Claudia Sepúlveda, Germán Avila, Claudia Loviso, Eugenia Orosco, Margarita Bonicatto, Cecilia Condes, Irene Velarde (Argentina) American Grapevine Culture and Research in Berisso, Argentina (pp 38-53)
Invited Review: The “Riverbank wine of Berisso”, made from american grapevine (Vitis labrusca var. Isabella), is a typical local product, original from an area deeply forgotten of the Pampa riverbank: the Berisso district (latitude 34°53′ South, longitude 57°54′ West), close to Buenos Aires city, one of the counties most affected by the big Argentinian economic crisis at the end of 2001. The value that distinguishes this product and its permanence throughout different historic moments is the know-how characteristic of a certain group: the wine producers from Berisso. That know-how is repeatedly transferred from generation to generation orally and practically, the productive techniques enabling the vineyard maintenance and its subsequent processing of wine. Recently, in Argentina the possibility of making abandoned regions dynamic is being taken into consideration in order to rescue the food production typical of the area and this process is based on local initiatives. This kind of action is associated with the changes in the food consumption pattern observed in the common urban consumers, where the revaluation of the beliefs related to rural customs, to the rescue of tradition, and to natural behavior is becoming increasingly important. The case of the riverbank wine of Berisso is an example that allowed the Facultad de Ciencias Agrarias y Forestales de la Universidad Nacional de La Plata, in the context of its basic functions – teaching, research and extension – to begin an integrated work anticipating some trends in Argentina already observed in other developed countries. Historical and sanitary aspects, phases of primary and industrial production, commercialization, comsumption and challenges to face about the case of the riverbank wine of Berisso are described in this review.
Marina Sisterna, Santiago Sarandón (Argentina) Wheat Grain Discoloration in Argentina: Current Status (pp 54-64)
Invited Review: Black point (BP) and smudge are discolorations of wheat and other cereal kernels and occur in all major crop-growing regions of the world. BP is defined as a distinct brown or black discoloration of the germ end and surrounding area. When the discoloration affects more than one-half of the kernel or extends into the crease it is interpreted as smudge. This disease is usually caused by fungi, though recent studies suggest it may be a result of abiotic stress conditions. Many of these fungi are saprophytic (non-pathogenic) and are commonly found growing on dead plant material, as the genus Alternaria, or are cereal pathogens such as Bipolaris sorokiniana. This discoloration reduces grain quality impairing flour, semolina and their products. Downgrading of discolored grains at the market can cause economic losses to producers. The development of BP is very dependent on weather, occurring in the field under conditions of high relative humidity or rainfall. BP can be partially controlled by reducing irrigation frequency after heading and by reducing nitrogen rates. Another alternative is the application of fungicide but its results are contradictory. Because BP can occur at damaging levels in some seasons despite modifications in cultural practices, the best option for control is to combine reduced input practices with BP-resistant cultivars. Current cultivars differ in the level of resistance or tolerance to the disease, although there are no completely resistant cultivars available. In Argentina, although this disease has been known since the 20th century, it has become important in the last 15 years. This review deals with the current status of this wheat grain disorder in Argentina.
Elsa L. Camadro (Argentina) Characterization of the Natural Genetic Diversity of Argentinean Potato Species and Manipulations for its Effective Use in Breeding (pp 65-71)
Invited Mini-Review: The common potato, Solanum tuberosum L. ssp. tuberosum, is a tetraploid allogamous species, clonally propagated for commercial purposes. Advances in breeding of this species are usually slow due to its narrow genetic base and tetrasomic inheritance, in contrast to other polyploid species of agronomic importance (i.e. wheat, tobacco) that have disomic inheritance with simpler genetic ratios. However, it has approximately 200 wild and cultivated closely related species that constitute an invaluable source of genes for desirable attributes in breeding. Most of these species are diploids that cannot be directly crossed to the the common potato due to the presence of pre- and post- zygotic hybridization barriers. These barriers, however, can be incomplete and, if properly identified, strategies can be devised to introgress desirable genes into the cultivated pool. At the Laboratory of Genetics, in Balcarce, studies are carried out (some of them in collaboration with other potato groups) since 1981 to characterize wild Argentinian potato germplasm using genetic, cytogenetic, biochemical and molecular approaches, in order to: (1) identify breeding barriers and establish their genetic bases and (2) develop strategies to circumvent them. Information, of both basic and applied value, is regularly generated. In the process, genetic materials are obtained (pre-breeding) that can be of use in breeding.
Andrea M. Clausen, Verónica N. Ispizúa, Ariana Digilio (Argentina) Native Andean Potato Varieties in Argentina: Conservation and Evaluation of an Endangered Genetic Resource (pp 72-82)
Invited Review: The native potatoes (Solanum tuberosum ssp. andigena and S. curtilobum)constitute a valuable genetic resource, adapted to grow under extreme environmental conditions in the Andean highlands. These landraces are grown by subsistence farmers and possess resistance to pests and diseases and environmental stresses that affect the potato crop. Several causes are affecting the persistence of the landraces in the areas studied. We present the results of collection and conservation initiatives carried out in Argentina and the current germplasm holdings at the Genetic Resources Network of INTA. The landraces have been evaluated by the use of morphological, agronomic and molecular markers, and evaluated against environmental stresses and diseases. Ongoing research on the Andean landraces will allow us to identify the genetic variability present in farmer’s fields and strengthen the activities carried out including farmers as well as public and private organizations.
Sara Isabel Alonso, Andrea Martina Clausen (Argentina) Evaluation of Italian Ryegrass Populations Naturalized in the Flooding Pampa of Argentina. II. Phenotypic Variability among Populations Growing in Different Soils (pp 83-92)
Original Research Paper: Naturalized populations of Italian ryegrass (Lolium multiflorum Lam.) grow in different environments in Buenos Aires Province (Argentina). Juvenile plants of a cultivar and 20 populations collected in central-east areas of this Province were analysed in two environments with different soil types (Argiudol and Natracuol). At each site, 40 plants per plot were transplanted isolated, in a complete randomized blocks with three replicates. Morphological and agronomic traits were registered and ANOVA between environments were performed, with the replicates nested in the environments, and the genetic determination grade (GDG) was estimated. With the data registered during the trial as well as other previously obtained for the same populations, the affinity among populations was calculated by multivariate analysis. The genotype × environmental interaction resulted negative only for plant diameter and dry matter production as a result of the poor variation of the populations in the Natracuol soil type. Differences among populations and between environments in the majority of the characters were detected and the GDG was low to medium. The best performance was detected in Argiudol soil as a result of the limiting conditions of the Natracuol soil on the populations. Cluster analysis of the data in each environment showed differences in the affinity of the populations. The provenance of the most different populations was in the periphery of the area collected, while the ones distributed in the central area presented an affinity superior to 50%. Principal components analysis and the minimum spanning tree contributed to establish the affinity of the populations.
Edmundo L. Ploschuk, Liliana B. Windauer (Argentina) Development of New Perennial Oil-Crops for Marginal Environments: Productivity of Lesquerella mendocina under Different Nitrogen Availability (pp 93-98)
Original Research Paper: Several reports are in agreement with the fact that perennial grain yields do not match of the analog annual species, but others revealed that the perennials may be high. Not enough knowledge about the impact of nutritional conditions on the maintenance of yield stability along different growing seasons is available for perennial grain crops. Lesquerella mendocina is a promising species native from Argentina that produces oil with hydroxy fatty acids (HFA) in the seeds. The objective of this work was to test the hypothesis that seed production and yield components during the second year do not decrease in L. mendocina under optimal N availability. An experiment was carried out outdoors during two consecutive years. In 2004, treatments consisted of a control under optimal N availability measured during the first growing season (LM1-1), and two treatments which plants remained fertilized during the first year and analyzed during the second growing season (LM2) under low (N-) and high (N+) N availability. In 2005, two additional N- and N+ treatments were applied (LM1-2) in order to compare the production in the first season with LM2 plants. Similar yields were found for LM2 N+ than those for LM1-1 and LM1-2 N+, despite the drastic reduction of plant density in the former. Higher individual seed yield and inflorescence peduncles compensated the lack of plant stand. LM2 yield was more affected by N availability than LM1-2, while no changes in seed allocation were produced by N either plant age. The results suggest that L. mendocina performs as a promissory species with stable yields along years if future breeding programs improve seed allocation and resistance to fungal diseases.
Paula Calvo, Alicia Carrera, Enrique Sánchez, Mónica Poverene (Argentina) Genetic Diversity in Wild Apple (Malus sp.) Populations in Argentina (pp 99-105)
Original Research Paper: In Argentina, wild apple trees are distributed in the western areas of Neuquén province, along the Andean low hillsides. A collection of 23 wild populations.was investigated with RAPD primers to evaluate variability and genetic relationships. The data were analyzed by multivariate analysis. A low germplasm variability of H = 0.115 was estimated with Nei’s genetic diversity index. Cluster and principal coordinate analyses did not reveal distinct geographic patterns or strong grouping among individuals of the same origin, but there was a clear partition between wild and cultivated materials. AMOVA showed the largest level of diversity within populations (57%). A strong human influence seems to have shaped wild apple distribution.
Natacha P. Chacoff, Carolina L. Morales, Lucas A. Garibaldi, Lorena Ashworth, Marcelo A. Aizen (Argentina) Pollinator Dependence of Argentinean Agriculture: Current Status and Temporal Analysis (pp 106-116)
Original Research Paper: A sizable proportion of agricultural production depends directly or indirectly on animal pollination but estimation of the size of this dependence is missing for most countries, even for some of the most important food producers. Here, we evaluate the current status and temporal trends (1961-2007) in pollinator dependency of Argentinean agriculture. We classified crops in categories according to their pollinator dependence, and estimated their harvested area, production, economic and nutritional values. We also estimated the expected production deficit in the absence of pollinators, the extra area needed to cope with this deficit, and trends in honeybee stocks. From a total of 68 crops, animal pollination increased directly production in 37 and indirectly in 13. More than half of the harvested area and total agricultural production corresponded to pollinator dependent crops, a trend highly influenced by the inclusion of soybean as a modestly dependent crop. Highly pollinator-dependent crops produced 2-4 times more income per hectare than any other crop, and modestly dependent crops bear on average the highest protein and fat content. During the study period the production deficit increased three-fold, reaching 12% in 2007, whereas the area needed to compensate for these deficiencies attained 24%. Regarding pollination services, indicators are mixed; whereas Argentinean honey-bee stock triplicates from 1961 to 2007, native forest area, a source of pollinator diversity, shrank to more than half since 1940’s. Experiments testing the degree of pollinator dependency on the quality and quantity of crop production for soybean varieties cultivated in Argentina are urgently needed. Our estimations depict an agriculture that is becoming more dependent on pollinators, but native forests and other native terrestrial habitats, which host most of the country’s pollinator diversity, are decreasing at an alarming rate.