Viabilidade técnica e econômica da produção de minimilho fertirrigado em Dourados-MS

Abstract

The bay corn has been gaining space in the Brazilian market stimulated by the canning industry and the country has productive potential and consumer market. The versatility of this product has provoked the opening of a new niche market, mainly for the family agriculture for the short period necessary for cultivation. The objective of this work was to evaluate technical aspects and economical viability of the baby corn culture, cultivated under nitrogen and potassium doses via fertirrigation in a dystroferric Red Latosol. The experiment was conducted in the irrigation and drainage area of the Faculty of Agrarian Sciences (FCA) of the Federal University of Grande Dourados (UFGD) in Dourados, MS, from April to July 2014. The climate of the region is of the mesothermic Cwa type and the average annual rainfall is 1500 mm and the mean air temperature is 22°C. The corn cultivar used was AG 1051, a double hybrid with semiprecoce cycle indicated for the production of green corn. The same was sown manually on April 4, 2014. For this, rows spaced between 0,80 m between each other and seeding depth of 0,05 m were made. The experimental design was in randomized blocks, in the subdivided plots scheme with four blocks. The plots were composed of nitrogen doses (zero, 75, 150, 225 and 300 kg ha-1) and the sub-plots of potassium doses (K2O) (zero, 50, 100, 150 and 200 kg ha-1). The baby corn crop was irrigated during the whole cycle using irrigation management based on the daily estimate of the reference evapotranspiration and the nitrogen and potassium treatments were applied using a fertilizer injection system, differential pressure type adapted to small areas or plots. The evaluated variables were: nitrogen and potassium leaf content, plant height, stalk diameter, spikelet length, spikelet diameter, total spikelet number, spikelet mass, total spikelet mass, number of commercial spikelets, mass of Commercial spikelets, percentage of commercial spikelets, agronomic efficiency of nitrogen and potassium and maximum economic efficiency. The variables were submitted to analysis of variance and, when significant, were interpreted through regression studies. It is concluded that the commercial mass is influenced by both nutrients, evidencing that up to the limit of the critical doses of nitrogen and potassium each kilogram per hectare of nitrogen and potassium increases the commercial spikelet mass in 34,28 kg ha-1. The maximum percentage of commercial spikelets is reached when applied with the combined dose of 159,78 kg ha-1 of N and 105,70 kg ha-1 of K2O applied via fertigation. The agronomic efficiency of nitrogen for the fertigated miniature crop decreases with the increase of the nitrogen doses in the order of 51 g for each kilo of nitrogen applied per hectare and the potassium efficiency decreases in the order of 22 g for each kilo of applied K2O per hectare. The higher profit fertirrigated babycorn with nitrogen and potassium is found using the associated doses of 150 kg N ha-1 and 50 kg ha-1 K2O.