Yield and quality of wheat seeds as a function of desiccation stages and herbicides

Abstract

This study aimed to evaluate the yield and seed quality of wheat, cultivar ‘Quartzo’, harvested after desiccation with two desiccants (glyphosate and paraquat) at two reproductive stages (11.2 and 11.3). The study used a randomized block experimental design in a 3 x 2 factorial arrangement (two desiccants and a control) and two growth stages of wheat, with four replications. The following were assessed: seed yield, thousand seed weight and seed quality (germination, first germination count, root and shoot weight, seedling dry and fresh weight, accelerated aging, electrical conductivity, cold germination, potassium leaching). Based on the results, it can be concluded that the use of desiccants on wheat at the two stages of development have not affected yield, but they have negatively influenced physiological seed quality. Generally, the herbicide glyphosate showed the lowest phytotoxic effect on seeds, and desiccant application at stage 11.2 resulted in higher physiological seed quality compared with application at stage 11.3.

Application of Non-Selective Herbicides in the Pre-Harvest of Wheat Damages Seed Quality

“…As for the application stage, [4] obtained an increase in germination in early applications, as in stage 11.2 [27]. This phenological stage comprises the interval between stage Z-83 and Z-87, in this way, opposing the results of the present study.…”

“…These two herbicides affect wheat germination, with a more pronounced effect for the second that is 7% more harmful than glyphosate [4]. The glufosinate-ammonium when applied in pre-harvest with 26, 33, 40 days after flowering does not affect the germination in relation to control, without application [12].…”

“…The SL and RL are decreased by the application of herbicides, regardless of the phenological stage of application, and there is a tendency for the maintenance of [4]. For glyphosate, radicle damage is much higher in relation to shoot, with an average reduction of 2.5 cm in relation to treatments without the application of herbicides [26].…”

“…The SDM was not affected by the use of herbicides, regardless of the application stage. From the Z-83 stage, [4] report that there is reduction in the mass accumulation of plants coming from desiccation. The dry mass is 10%…”

“…Harvesting with seed moisture between 30% -35% maintains the compounds of production, however, the germination of seeds is impaired [3]. Another alternative is to promote drying of the plant by applying non-selective herbicides in order to anticipate the harvest [4].…”