PRODUCTION PERFORMANCE OF BRS TUMUCUMAQUE COWPEA UNDER DIFFERENT PLANT DENSITIES AND WATER REGIMES1

Josimar Soares Da Silva Júnior,Edson Alves Bastos,Valdenir Queiroz Ribeiro,Milton José Cardoso,Aderson Soares De Andrade Junior

doi:10.1590/1983-21252020v33n122rc

Abstract

ABSTRACT Cowpea is a legume of great socioeconomic importance for the North and Northeast regions of Brazil. However, studies to evaluate its production performance when cultivated under irrigated regime and under different plant densities are necessary. The objective of this work was to evaluate the effects of different water regimes and different plant densities on grain yield, production components and water use efficiency, and on the correlation between grain yield and production components of BRS Tumucumaque cowpea cultivar. The experiment was carried out at Embrapa Meio-Norte experimental area, in Teresina, Piauí State, Brazil, from June to September 2017, in an Argissolo Vermelho-Amarelo eutrófico (Ultisol). A randomized complete block design was used, in a split-plot scheme with four replicates, in which the water regimes occupied the plots (187.7; 233.5; 263.5 and 288.7 mm) and plant densities, the subplots (12; 16; 20 and 24 plants m-2). The number of pods per plant, number of pods per square meter, pod length, dry grain yield and water use efficiency were evaluated. The maximum dry grain yield reached was 1,694.46 kg ha-1, with application of 288.7 mm and density of 20.4 plants m-2. The production component number of pods per square meter was the most correlated with dry grain yield.

Highlights

Cowpea is a crop of great socioeconomic importance and is cultivated in large areas of the globe
The percentages of variation in the preestablished irrigation depths were sufficient to promote a clear variation in soil moisture between treatments and enable significant differences between grain yields and production components
This fact did not interfere in the results of the study, because it occurred at the end of the reproductive stage of cowpea, marked by the senescence of plants (BASTOS et al, 2008) and, according to Bezerra et al (2003), the most critical stage of the crop for water stress is grain filling

Summary

Introduction

Cowpea is a crop of great socioeconomic importance and is cultivated in large areas of the globe. Plant density stands out, a factor that directly influences morphophysiological characteristics and grain yield. Another important management practice is irrigation, which can minimize the risks due to water deficit. In this context, some studies have been conducted to define the density and/or spacing of cowpea plants that promotes maximum grain yield in irrigated or rainfed production system (SOUZA et al, 2011; BEZERRA et al, 2012; SANTOS, 2013; BEZERRA et al, 2014; LOCATELLI et al, 2014; OLIVEIRA et al, 2015; COSTA JÚNIOR et al, 2017; MONTEIRO et al, 2017; CARDOSO, MELO and RIBEIRO, 2018). Upright or semi-erect cowpea cultivars withstand a higher plant density when compared to those of semi-prostrate growth habit

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Conclusion