Trinexapac-ethyl delays lodging and increases seed yield in perennial ryegrass seed crops

Abstract

The plant growth regulator trinexapac-ethyl (TE) is widely used to enhance ryegrass seed yields by reducing lodging (i.e. delaying collapse of the crop). However, lodging data are usually a single evaluation related to TE rate for a particular date of measurement. In eight field trials with varying rates of TE, weekly lodging assessments were made from full head emergence and days to 50% lodging were determined. In all trials, dynamic assessment of TE treatment showed there was a strong positive correlation (R 2 00.82) between the number of days to 50% lodging and seed yield. Nil TE reached 50% lodging in 7 days compared with 33 days for TE treatments of 400 g ha . On average, one days' delay in reaching 50% lodging increased seed yield by 24 kg ha(1 (response range 16Á33 kg ha(1 ). The data indicate that TE rate per se is less important than the rate required to delay the date that 50% lodging is reached. The seed yield response was linear for delayed lodging from full head emergence to harvest, suggesting that the highest yields are achieved if the crop is not more than 50% lodged at harvest.

Trinexapac-ethyl rate and application timing effects on seed yield and yield components in tall fescue

“…The increased HI was the result of improved seed yield and small, not statistically significant reductions in biomass (Table 2). Similar effects of TE application on HI have been observed in tall fescue and in perennial ryegrass seed crops (Rolston et al, 2010;Chastain et al, 2014a). Crop canopy modification by TE enabled efficient partitioning of dry matter to seed yield in strong creeping red fescue (Zapiola et al, 2006(Zapiola et al, , 2014; however, improved carbon partitioning to seed alone could not account for the increased seed yield resulting from lodging control in perennial ryegrass .…”

“…adopted for use as a lodging control agent in forage and turf grass seed production (Zapiola et al, 2006;Rolston et al, 2010). Reduction in stem length and lodging by TE resulted in increased seed yield in perennial ryegrass (Lolium perenne L.) seed crops (Borm and van den Berg, 2008;Rolston et al, 2010;Koeritz et al, 2013;Chastain et al, 2014a).…”

“…Reduction in stem length and lodging by TE resulted in increased seed yield in perennial ryegrass (Lolium perenne L.) seed crops (Borm and van den Berg, 2008;Rolston et al, 2010;Koeritz et al, 2013;Chastain et al, 2014a). While the effects of TE on lodging control and seed yield in perennial ryegrass (Rolston et al, 2010;Koeritz et al, 2013;Chastain et al, 2014a) and strong creeping red fescue (Festuca rubra L. subsp. rubra) seed crops (Zapiola et al, 2006(Zapiola et al, , 2014 are well known, there have only been three investigations on these effects of TE in tall fescue.…”

Interactive Role of Fungicides and Plant Growth Regulator (Trinexapac) on Seed Yield and Oil Quality of Winter Rapeseed

“…Heavy-lodged plants of untreated plots attained the lowest TGW at both stations (Table 3). Due to lodging, growing conditions are unfavorable for seed filling because of reduced light, which has a negative impact on photosynthesis [16][17][18]. Severe lodging interferes with the transport of nutrients and moisture from the soil and, thus, with storage in developing seeds.…”

“…Berry and Spink (2009) [19] also reported that Caramba (metconazole) application in winter rapeseed enhanced TGW by increasing leaf area index and developing optimum size of the crop canopy, which helped to reduce lodging. Growth regulator Moddus (trinexapac) treatment attained maximum value of TGW and minimal lodging at Giessen, while at RH the same treatment plots were lodged [17][18][19][20]. This was caused by a thunderstorm at the time of maturity.…”