Crop yield response to water - Cra

Lead AuthorRoberto Quiroz(CIP, Lima, Peru)PotatoContributing AuthorsEnrique Chujoy,Victor Mares(CIP, Lima, Peru)AcknowledgmentsMargarita García-Vila(University of Cordoba,Cordoba, Spain),Christian R. Jensen(Royal Veterinary and AgriculturalUniversity, Copenhagen,Denmark),Ne Bambi Lutaladio(FAO, Plant Production andProtection Division, Rome, Italy)scientists contributingwith experimentalDATA and tests for thecalibration of AquaCroPJohn Annandale,Martin J. Steyn(University of Pretoria,Pretoria, South Africa),Carolina Barreda, KeithMacKerron(Scottish Crop Research Institute,Dundee, UK),Roberto Quiroz, RaymundoGutierrez and Carla Gavilán(CIP, Lima, Peru),David Wolfe(Cornell University,New York, USA)General descriptionPotato (Solanum tuberosum) is a starchy tuberous crop that originatedin the Andes, and the two subspecies of the cultivated potato,S. tuberosum tuberosum and S. tuberosum andigena, account fornearly all of the world’s production. Potato ranks as the fourth largest foodcrop in the world, following rice, wheat, and maize, with a production of329 million tonne on 18.6 million ha (FAO, 2011) (Figure 1). The largestpotato production continents are Asia and Europe with 44 percent and 37percent of the world’s production, respectively. China, India, the RussianFederation, Ukraine and the United States are the largest producers. Rapidexpansion of potato production over the past 20 years has occurred indeveloping countries, particularly in Africa and Asia where production hasmore than doubled. Potato remains an essential crop in developed countrieswhere per capita production is still the highest in the world (Figure 2).Potato is particularly suited to a cool climate. It is widely cultivated in thetemperate, subtropical, and cool tropical regions where it is grown as amonoculture, in crop rotation, or in multiple cropping. Rotation with othercrops is often necessary to ameliorate problems of disease and other pests.In temperate regions, cold temperature and a short frost-free period limitpotato production to once a year as a monoculture, or in a three or moreyear crop rotation with maize, soybean, sorghum, or sugar beet in areas withhigh rainfall or irrigation; and with wheat, maize, millet, barley, and oatsin arid and semi-arid environments. This region includes the water deficitareas of northern China where potato is a rainfed and short season crop (90-110 days); supplementary irrigation is needed but not frequently applied. Innorthern Europe and North America, potato production is generally carriedout with intensive agricultural practices, including high rates of fertilization,pesticide use, and irrigation where necessary. Two- to four-year rotationsinclude oilseeds, cereals and legumes. In the subtropics potato is found ina range of cropping systems. It is in multiple cropping systems with two oreven three crops per year in rotation with wheat or maize in the centralplains of China, in intercropping systems particularly with maize at lowerelevations there, as a single spring crop in higher altitudes of southwestChina, or as an irrigated and short season winter crop in rotation with riceor wheat in the Indogangetic plains, lower elevations of southwest Chinaand North Vietnam. In the cool tropics, potato is commonly a once-a-year(in a couple of countries twice-a-year) rainfed crop, a long growing season(180 days) monoculture or is included in rotations with maize, legumes,184crop yield response to water