Response of hybrid squash Tetsukabuto to water depths and doses of nitrogen

Waldir A Marouelli,Marcos B Braga,Geovani B Amaro

doi:10.1590/s0102-053620170314

Abstract

ABSTRACT The aim of this work was to evaluate, under the Cerrado conditions of Central Brazil, the effect of different amounts of water and nitrogen (N) on the production performance of hybrid squash Tetsukabuto. Five water depths were tested in 2008 (185, 265, 343, 408 and 477 mm) and four in 2009 (286, 360, 430 and 540 mm), using line source sprinkler irrigation. The doses of N (0, 50, 100, 150 and 200 kg/ha) were the same in both experiments. The experimental design was a split-plot strip block with three replications. Fruit productivity was affected by the interaction between water depths and doses of N. Higher marketable productivity was observed on plants cultivated with the use of 477 and 492 mm of water and 105 and 146 kg/ha of N in 2008 and 2009, respectively. Ninety-five percent of the maximum productivity was reached by using 422 and 442 mm of water and 62 and 96 kg/ha of N in 2008 and 2009, respectively. The soil water tension thresholds, associated with the water depths that enabled 95 to 100% of the maximum productivity, ranged from 24 to 55 kPa. Higher water use efficiency occurred for water depths of 334 and 423 mm and doses of N of 90 and 120 kg/ha in 2008 and 2009, respectively. The use efficiency of applied N improved with increasing water depth and decreasing dose of N. Density, total soluble solids content and fruit pulp yield neither were affected by water depths nor by the doses of N.

Highlights

O objetivo deste trabalho foi avaliar a resposta da abóbora híbrida tipo Tetsukabuto a diferentes lâminas de água e doses de nitrogênio (N), nas condições de Cerrado do Brasil Central
According to Sediyama et al (2009), this increase is due to positive characteristics of growing, high nutritional quality, excellent organoleptic characteristics, great cooking versatility and extended postharvest conservation of fruits, especially when compared to open-pollinated squash cultivars
The squash crop is moderately tolerant to water deficit (Kemble & Sanders, 2000), irrigation allows productivity gains, especially in regions characterized by irregular rainfall distribution and soils with low water-holding capacity (Napier, 2009; Fandika et al, 2011)

Summary

Introduction

O objetivo deste trabalho foi avaliar a resposta da abóbora híbrida tipo Tetsukabuto a diferentes lâminas de água e doses de nitrogênio (N), nas condições de Cerrado do Brasil Central. A produtividade de frutos foi influenciada pela interação entre lâmina de água e dose de N. Maior produtividade comercial foi obtida em plantas cultivadas com 477 e 492 mm de água e 105 e 146 kg/ha de N em 2008 e 2009, respectivamente. 95% foram alcançados com 422 e 442 mm de água e 62 e 96 kg/ha de N em 2008 e 2009, respectivamente. As tensões-limite de água no solo, associadas às lâminas que possibilitaram 95 a 100% da produtividade máxima, variaram de 24 a 55 kPa. Maior eficiência de uso de água ocorreu para as lâminas de 334 e 423 mm e doses de N de 90 e 120 kg/ha em 2008 e 2009, respectivamente. Whereas the water deficit in the soil limits the solubilization and the transport of N through mass flow to the roots, excess irrigation favors leaching. Yields can be adversely affected by excess water, which reduces soil aeration, promotes nutrient leaching and increases disease occurrence (Shock et al, 2007; Zvalo & Respondek, 2007; Amer, 2011; Aegerter et al, 2013)

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