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Chillán, Chile

Gonzalez M.I.,INIA Quilamapu
Acta Horticulturae | Year: 2012

The trial was established on 30 January 2007 using 12-week-old plants in a soil of volcanic origin at Chillán (36°32'S; 71°55'W). The planting date was not the most adequate, because we received the seeds very late in the season. Nevertheless, the plants grew vigorously the first season until temperature started to decrease (April 2007). The experimental design is randomized complete blocks with four replications. Plots have two rows of plants 7 m long. Planting distances were 1.5 m between rows and 0.25 m between plants. Planting depth was 25 cm. The evaluated cultivars are: 'Pacific 2000', '3 x Phy20', '73 x 22', 'Fileas', 'Mondeo', 'DePaoli', 'UC 157', 'Atlas', 'Jersey Giant', 'J. Supreme' A (from J.A. Farms) and B (from Rutgers University), 'J. Knight', 'J. Deluxe', 'New Jersey 951', 'NJ 953', 'NJ 956', 'NJ 978', 'NJ 1025', 'NJ 1031', 'NJ 1119', and 'NJ 1149'. We have only 17 plants of 'Jersey Deluxe' which were included in the second block as a satellite plot. Plots were harvested daily during 38 days for the first time in 2008. Spears were cut at 18 cm long after harvest. Cultivars with highest marketable yield were 'NJ 978' (3134 kg/ha), 'NJ 1031' (3109 kg/ha), 'NJ 956' (2897 kg/ha), 'NJ 953' (2895 kg/ha), 'NJ 951' (2781 kg/ha), 'J. Giant' (2686 kg/ha), and 'Mondeo' (2646 kg/ha). The lowest marketable yield was given by 'J. Supreme' B (1600 kg/ha), '73 x 22' (1605 kg/ha), 'DePaoli' (1658 kg/ha), 'J. Supreme' A (1752 kg/ha), 'NJ 1119' (1876 kg/ha) and 'UC 157' (1912 kg/ha). Number of spears per m 2 ranked from 10.3 ('NJ 1119') to 25 ('NJ 978'). Spears infected by purple spot (Stemphylium vesicarium) at harvest ranked from 0% ('NJ 1149') to 17.2% ('Mondeo') of total yield. Plants affected by Phytophthora megasperma during summer ranked from 9.3% ('3 x Phy20') to 61.5% ('NJ 953').

Gonzalez-Talice J.,University of Talca | Yuri J.A.,University of Talca | Lepe V.,University of Talca | Hirzel J.,INIA Quilamapu | del Pozo A.,University of Talca
Scientia Horticulturae | Year: 2012

Limitations in the availability of water for agricultural purposes makes necessary to improve irrigation planning and the use efficiency of this resource. Plant-water relationships have been study in apple trees but differences in water use among cultivars have received little attention. In this study, the monthly and seasonal water consumption in cvs. Fuji, Galaxy and Granny Smith were evaluated in a drainage lysimeter, located in field conditions in a Mediterranean environment of central Chile. Soil and stem water potential indicated that plants were not exposed to water stress throughout the experiment. The amount of water used increased exponentially from the second (368Ltree -1) to the sixth (694Ltree -1) growing seasons in the three cultivars. The monthly water use and crop basal coefficient (K cb) varied among cultivars and increased with tree age. During fruit production (January and February) water use and K cb increased exponentially with tree age, but linearly during vegetative growth (December and March). Galaxy cultivar presented lower leaf area (27%) but higher water use per trunk cross-sectional area and per leaf area (7% and 19%, respectively) than cv. Granny Smith, suggesting higher hydraulic conductance and/or stomatal conductance in the former cultivar. © 2012 Elsevier B.V.

Arnold T.,Drinking Water Source Protection | Uribe H.,INIA Quilamapu | Troost C.,University of Hohenheim | Berger T.,University of Hohenheim
Modelling for Environment's Sake: Proceedings of the 5th Biennial Conference of the International Environmental Modelling and Software Society, iEMSs 2010 | Year: 2010

For agricultural production, climate change will have the greatest impact on water availability. At the same time, rural farming communities are at the heart of poverty reduction strategies. Furthermore, healthy rural societies must be maintained to contain urbanization and associated sprawl. Thus, sustainable adaptation strategies must take into account the complexity of societal responses. However, scientific tools to assess such interactions are lacking. A promising approach is the integration of data and models across scientific disciplines and in collaboration with local stakeholders. Empirical, process-oriented models can even quantify these interactions and feedback. As a contribution to this challenge, the project 'Integrating governance and modeling' combined the agricultural economics multi-agent farm decision model MPMAS and the hydrological model WASIM-ETH dynamically. Models were calibrated empirically, with increasing level of detail and interactions. The stepwise and iterative integration/calibration of these coupled models allowed for sensitivity assessment across disciplines but it also pointed to the relevance of knowledge gaps along disciplinary divides: production risk at multiple decision horizons, the unequal susceptibility of different marketing venues in case of production failures, and farmers' unequal access to water under fluctuating supply.

Arnold T.,Drinking Water Source Protection | Uribe H.,INIA Quilamapu | Troost C.,University of Hohenheim | Berger T.,University of Hohenheim
Modelling for Environment's Sake: Proceedings of the 5th Biennial Conference of the International Environmental Modelling and Software Society, iEMSs 2010 | Year: 2010

Fresh and clean water is one of the scarcest and most vital resources to humankind. Agriculture is the largest global water user. Irrigation managers must orchestrate water use at the catchment scale, balancing the management of supply and demand and taking into account the benefits from water use, its distribution among water users and environmental concerns. We present results from the integrated modeling of irrigation water use at catchment scale. An extended hydrological runoff model WaSiM-ETH that depicts inefficient surface irrigation was integrated with and coupled to a parametric model for irrigation water distribution, which is linked to the bio-economic multi-agent model MP-MAS that represents farmers as water users. Models were calibrated empirically, first as standalone models and then with increasing complexity of interactions. The integration of process across such long chain of reasoning resulted in an improved system understanding along disciplinary boundaries. The case study presented is irrigation water use within the Chilean Region of Maule. We analyze how farmers whose endowment with formal water rights is insufficient may depend on spillover water, and specifically the distribution of benefits from improvements in canal conductive efficiency across the farming community.

Gonzalez M.I.,INIA Quilamapu | Cespedes C.,INIA Quilamapu
Acta Horticulturae | Year: 2012

Salt application to the soil in asparagus plantations is an old practice which has been recommended to improve the asparagus crops damaged by Fusarium. A trial was established on a 5-year-old 'UC 157' planting in a soil of volcanic origin at Chillán (36°32'S; 71°55'W) to evaluate the effect of salt application in a sector affected by Fusarium spp. The experimental design was randomized complete blocks with five replications. Four doses of sodium chloride: 0, 600, 1200, and 1800 kg ha-1 were applied during summer (January) for seven years (2002 to 2008). There was no effect of salt application on asparagus yield during the seven harvest seasons, not also on the number of plants and number of stalks per plant at the end of each growing season. The number of healthy plants diminished from year 2002 to 2004 in all treatments, being constant the following years. On the other hand, the number of fern stalks per plant has increased in all treatments with passing of the years. The stability of soil aggregates was also evaluated in three opportunities of the year 2007: before, 15 days, and 30 days after salt application. Although there was no effect of the treatments on this parameter, a decrease of the stability in the time was observed (P ≤ 0.05), being more severe with the highest salt doses (1200 and 1800 kg ha-1).

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