Grain Sorghum Response to Row Spacing and Plant Populations in the Texas Coastal Bend Region

Carlos J Fernandez,W James Grichar,Dan D Fromme

doi:10.1155/2012/238634

Abstract

Two grain sorghum (Sorghum bicolor L. Moench) studies were conducted in the Coastal Bend Region of Texas over a two-year period. In one study, sorghum growth and yield were compared when planted in a single row on beds or planted in twin rows on beds with different plant populations under dryland or irrigation. Above average rainfall occurred in May 2000 which resulted in twin rows at any plant population producing higher yields than the single row at lower plant population. In 2001, single-row plantings with either plant population (124,000–160,000 or 161,000–198,000 plants/ha) produced higher yield than twin rows planted at 161,000–198,000 plants/ha. Under irrigation, twin rows planted at 161,000–198,000 plants/ha produced higher yields than single row at the same population; however, no other yield differences were noted when row systems or plant populations were compared. In another study, 38 cm row spacings were compared with 76 cm row spacings under two plant populations. In 2000, when rains fell at an opportune time, no yield differences were noted; however, in 2001 with below average rainfall, the 76 cm plantings at 170,000–200,000 and 210,000–240,000 plants/ha produced higher yield than the 38 cm plantings at those same plant populations.

Highlights

Row spacing and plant populations are variables that can have a significant impact on the net returns of sorghum producers
The first study was conducted under irrigated conditions in 2000 and dryland conditions in 2000 and 2001 to determine grain sorghum response to twin rows planted on a bed compared to a single row planted on a bed using three different plant populations
Another study was conducted under dryland conditions in 2000 and 2001 to determine grain sorghum response to two different row spacings (38 and 76 cm) and two different plant populations

Summary

Introduction

Row spacing and plant populations are variables that can have a significant impact on the net returns of sorghum producers. Grain sorghum along the Texas Gulf Coast is commonly cultivated in rows 76–102 cm apart [1]. Recent technological developments in farming equipment and improved herbicides open new doors for using rows narrower than 76 cm or twin rows on a single bed in grain sorghum production. The use of narrow rows in grain sorghum production is not new. A number of previous studies published in the late 1950s and 1960s showed yield increases when grain sorghum was planted in narrow rows [2, 3]. Though optimal plant densities for grain sorghum differ from region to another, previous research has indicated that grain yields generally increase as plant populations increase [4,5,6]. At lower than suggested plant densities, grain sorghum head number per plant or seed number per head increased when compared to the recommended plant density [7,8,9,10]

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