POTATO PRODUCTION AS AFFECTED BY CROP PARAMETERS AND METEOROLOGICAL ELEMENTS

摘要

Meteorological elements directly influence crop potential productivity, regulating its transpiration, photosynthesis, and respiration processes in such a way as to control the growth and development of the plants throughout their physiological mechanisms at a given site. The interaction of the meteorological factors with crop responses is complex and has been the target of attention of many researchers from all over the world. There is currently a great deal of interest in estimating crop productivity as a function of climate by means of different crop weather models in order to help growers choose planting locations and timing to produce high yields with good tuber quality under site-specific atmospheric conditions. In this manuscript an agrometeorological model based on maximum carbon dioxide assimilation rates for C3 plants, fraction of photosynthetically active radiation, air temperature, photoperiod duration, and crop parameters is assessed as to its performance under tropical conditions. Crop parameters include leaf area and harvest indexes, dry matter content of potato tubers, and crop cycles to estimate potato potential yields. Productivity obtained with the cultivar Itarare, grown with adequate soil water supply conditions at four different sites in the State of Sao Paulo (Itarare, Piracicaba, Tatui, and Sao Manuel), Brazil, were used to test the model. The results showed that the agrometeorological model tested under the climatic conditions of the State of Sao Paulo in general underestimated irrigated potato yield by less than 10%. This justifies the recommendation to test the performance of the model in study in other climatic regions for different crops and genotypes under optimal irrigation conditions in further scientific investigations. We reached the conclusion that the agrometeorological model taking into account information on leaf area index, photoperiod duration, photosynthetically active radiation and air temperature is feasible to estimate potential tuber yield at a commercial scale. The performance test shows that it can then be used to forecast harvest time, and also as an effective tool to predict the suitability of potential regions to the cultivation of potato crop, cultivar Itarare, at the State of Sao Paulo, Brazil.