ABSTRACT
Cowpea is the third most cultivated legume in the world, and its cultivation can be intended for both grains and seeds. Plants intended for seed production, when exposed to water deficit, may compromise their physical and physiological quality, necessitating the development of strategies to minimize their damage, such as the application of salicylic acid and HumigelPlus® polymer. The objective of this study was to evaluate salicylic acid and HumigelPlus® polymer concentrations to reduce the effects of water deficit on the physical and physiological quality of cowpea seeds. The landrace cowpea seeds used in this study were sourced from two field experiments (Summer and spring). The treatments consisted of five concentrations of salicylic acid (0, 0.29, 1, 1.71, and 2 mM) and five concentrations of HumigelPlus® polymer (0, 0.29, 1, 1.71, and 2%) combined according to the Central Composite Design and a control group (absence of water deficit and application of salicylic acid and HumigelPlus® polymer). The values of electrical conductivity, germination, emergence, weight, and water content of cowpea seeds were higher with the application of salicylic acid (mM) and HumigelPlus® polymer (%) concentrations between 0.29 and 2, regardless of the season. The application of salicylic acid (mM) and HumigelPlus® polymer (%) concentrations between 0.29 and 2, both in summer and spring cultivation, reduces the effects of water deficit on the physical and physiological quality of cowpea seeds.
Key words:
Vigna unguiculata (L.) Walp.; water scarcity; phytohormones; monomers
HIGHLIGHTS:
0.29 to 2 mM of salicylic acid and HumigelPlus® polymer improve the quality of cowpea seeds grown under water deficit.
0.29 and 1.71 mM of salicylic acid and HumigelPlus® polymer improve the physical quality of cowpea seeds under water deficit.
1 to 2 mM of salicylic acid and HumigelPlus® polymer increase the physiological vig-or of cowpea seeds under water deficit.
Thumbnail
Thumbnail
Thumbnail
Thumbnail
Kc - Crop coefficient; ETo - Reference evapotranspiration; ETc - Crop evapotranspiration; R - Rainfall; NID - Net irrigation depth; GID - Gross irrigation depth; WSI - Water stress interval
MC - Moisture content; FGC - First germination count; GP - Final germination percentage; FEC - First emergence Count; EP - Final emergence percentage; EC - Electrical conductivity; AWA - Water imbibition by the seed; TSW - Thousand-seed weight. 0.00 and 0.00 (S0P0); 0.29 and 0.29 (S0.29P0.29); 1.71 and 0.29 (S1.71P0.29); 0.29 and 1.71 (S0.29P1.71); 1.71 and 1.71 (S1.71P1.71); 1.00 and 0.00 (S1P0); 1.00 and 2.00 (S1P2); 2.00 and 1.00 (S2P1); 0.00 and 1.00 (S0P1); 1.00 mM of salicylic acid and 1.00% of HumigelPlus® polymer (S1P1), respectively
MC - Moisture content; FGC - First germination count; GP - Final germination percentage; FEC - First emergence Count; EP - Final emergence percentage; EC - Electrical conductivity; AWA - Water imbibition by the seed; TSW - Thousand-seed weight; *, **, and *** - Significant at p ≤ 0.05, p ≤ 0.01 and p ≤ 0.01 by the t-test, respectively