**8. Results**

Since weather conditions and sesame development varied from year-to-year and across locations no attempt was made to combine data across years or locations. Also, in some years (2006 at Lorenzo, 2007 at Uvalde), the PRE PM stage occurred sooner than anticipated and a timely herbicide application was not made. Since drydown in 2008 at Uvalde occurred so quickly due to the extreme drought conditions, an accurate assessment of sesame drydown could not be obtained. An herbicide treatment by application timing interaction was noted in each year for drydown and sesame yield; therefore, data are presented separately for herbicide treatment and application timing.

#### **8.1 Sesame drydown**

#### *8.1.1 Lorenzo*

In 2006, when the PM applications were compared, diquat-dibromide and glufosinate-ammonium accelerated drydown more than glyphosate or carfentrazone-ethyl (**Table 2**). With the POST PM timing, a rate effect was noted with carfentrazone-ethyl, diquat-dibromide, and glyphosate but not glufosinateammonium. The high rates of glyphosate and diquat-dibromide improved drydown 44–54% while the high rate of carfentrazone-ethyl improved drydown 29% when compared with the lower rates while virtually no difference was noted between glufosinate-ammonium rates. The high rate of glyphosate resulted in the greater drydown than other herbicides. All treatments improved drydown over the untreated check. In 2007 at the PRE PM and PM stage, diquat-dibromide at 0.28 and 0.56 kg ai ha<sup>1</sup> accelerated sesame drydown greater then glufosinateammonium at 0.47 and 0.58 kg ai ha<sup>1</sup> , which was greater than glyphosate at 0.63 and 0.84 kg ae ha<sup>1</sup> ; however, the high rate of glyphosate and both rates of glufosinate-ammonium performed similarly at the POST PM stage (**Table 2**). Diquat-dibromide at either rate applied POST PM provided ≥87% sesame drydown. Sesame drydown with the untreated check was ≤39% at all application stages.

In 2008 at the PRE PM stage, diquat-dibromide at 0.28 and 0.56 kg ai ha<sup>1</sup> and glufosinate-ammonium at 0.47 kg ha<sup>1</sup> produced 63–80% drydown while both rates of glyphosate and the untreated check resulted in <10% drydown (**Table 2**). Carfentrazone-ethyl at 0.018 and 0.035 kg ai ha<sup>1</sup> was intermediate in sesame


**8.2 Sesame yield**

**Carfentrazone-ethyl (kg ai ha<sup>1</sup> )**

*DOI: http://dx.doi.org/10.5772/intechopen.91011*

LSD (0.05) 250

LSD (0.05) 191

LSD (0.05) 197

LSD (0.05) NS

LSD (0.05) 217

*Sesame yield at Lorenzo and Uvalde as influenced by drydown herbicides.*

In 2006 at the PM stage, diquat-dibromide at 0.28 kg ai ha<sup>1</sup> and glufosinateammonium at 0.58 kg ai ha<sup>1</sup> produced yields that were lower than the untreated check (**Table 3**). None of the other herbicide treatments produced yields that were different from the untreated check. At POST PM, all sesame yields were lower than the untreated check and no differences were noted between herbicide treatments.

Stage<sup>a</sup> 0.018 0.035 0.28 0.56 0.47 0.58 0.63 0.84 Check

**Glufosinateammonium (kg ai ha<sup>1</sup> )**

**Glyphosate (kg ae ha<sup>1</sup>**

**)**

**Diquatdibromide (kg ai ha<sup>1</sup> )**

*Effects of Harvest Aids on Sesame (*Sesamum indicum *L.) Drydown and Maturity*

PRE PM — — — — — — —— PM 650 583 466 525 554 408 670 637

PRE PM — — 1282 1345 1364 1298 1058 1132 PM — — 1357 1383 1409 1361 1245 1139

PRE PM 785 890 818 890 946 773 670 818 PM 753 795 998 964 773 868 762 841

PRE PM — — — — — — —— PM — — 1535 1657 1562 1602 1645 1444

PRE PM — — —— — — 1344 1330 PM — — —— — — 1406 1352

POST PM 451 412 247 448 448 417 433 327 717

POST PM — — 1195 1325 1151 1158 1280 1049 1091

POST PM 863 829 751 1002 860 836 874 778 851

POST PM — — 1473 1506 1585 1475 1547 1506 1645

POST PM — — 1310 1304 1350 1390 1432 1562 1430

*PRE PM, prior to physiological maturity; PM, physiological maturity; POST PM, after physiological maturity.*

*8.2.1 Lorenzo*

Lorenzo (kg ha<sup>1</sup> )

2006

2007

2008

Uvalde 2007

2008

*a*

**225**

**Table 3.**

*a PRE PM, prior to physiological maturity; PM, physiological maturity; POST PM, after physiological maturity.*

#### **Table 2.**

*Sesame drydown (7–14 d after treatment) at Lorenzo and Uvalde as influenced by herbicides.*

drydown. At the PM stage, diquat-dibromide at either rate produced the greatest drydown (63–70%), glufosinate-ammonium was intermediate (45–48%) and carfentrazone-ethyl and glyphosate resulted in ≤18% drydown. At the POST PM stage, the high rates of carfentrazone-ethyl and glyphosate and both rates of diquatdibromide and glufosinate-ammonium resulted in ≥94% drydown while the untreated check showed only 28% drydown.
