Agronomic Evaluation of Sweet Sorghum in Semiarid Region: Cultivar and Spacing Effects

Tatiana Maria Da Silva,Bruno França Da Trindade Lessa,Joana Gomes De Moura,Lamartine Soares Cardoso De Oliveira,Alexandre Bosco De Oliveira

doi:10.5539/jas.v10n10p103

Abstract

The objective of this study was to evaluate the agronomic characteristics of two sweet sorghum varieties for row spacing in the semiarid region of the State of Cear&aacute;, Brazil. Hence, an experiment was carried out on the Experimental Farm of the Federal University of Cear&aacute;, in two agricultural cycles (2015 and 2016), in sandy loam Planosol during the rainy season. Two sweet sorghum varieties (BRS 506 and SF 15), cultivated at 50, 60, 70, and 80 cm row spacing, were evaluated at different times after sowing (30, 45, 60, 75, and 90 days), in a randomized block design repeated four times in the arrangement of subdivided plots (2 &times; 4 &times; 5). The BRS 506 variety had higher mean number of leaves and leaf angle +3 in the two cycles evaluated. The highest mean plant height was observed at 90 DAS (328.11 cm). The stalk diameter at 15.59 mm was greatest with 70 cm spacing between rows. The chlorophyll content of the leaves may be influenced by stress factors, such as water and mineral deficiency, primarily nitrogen. The best results for chlorophyll occurred in the first cycle, in which the greatest mean was observed at 75 days, while in the second cycle, a year that presented low precipitation (water stress), the greatest means were observed at 30 days. Taking into consideration our results, BRS 506 variety is recommended for cultivation in semiarid northeastern Brazil, presenting good agronomic characteristics, when sown with 70 cm spacing between the rows.

Highlights

The semiarid region of Brazil has climatic characteristics that often limit agricultural production under natural conditions, due to its intense insolation, high temperatures, and irregular rainfall generally concentrated in a short period of time
To take full advantage of the real conditions faced in the northeastern Brazil, our objective was to evaluate the agronomic characteristics of two sweet sorghum varieties as a function of the spacing between rows in the semiarid region of the state of Ceará
The highest mean number of leaves was observed at 60 days after sowing (DAS), while the greatest angle occurred at 90 DAS for both crop cycles (Table 1)

Summary

Introduction

The semiarid region of Brazil has climatic characteristics that often limit agricultural production under natural conditions, due to its intense insolation, high temperatures, and irregular rainfall generally concentrated in a short period of time. This scenario has been intensifying by climate change (Moura et al, 2007; Oliveira et al, 2012; Nunes et al, 2014). Sweet sorghum can be harvested between the period of sugarcane harvests, benefiting the sugarcane industry, by reducing the idle time and generating raw material to produce ethanol during this period It produces substantial biomass, has an early harvest, and uses the same industrialization process as sugarcane. These factors make it the first option for the renewal of the cultivation area, aiming to anticipate the milling period by about 45 days (Santos et al, 2015; Silva et al, 2018)

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Conclusion