Foliar spray can improve rapeseed yield components under continuous irrigation

Abstract

Applying climate-smart agriculture practices, such as foliar spraying with growth stimulants and improving drought tolerance, seems to be a rational solution in drought-prone areas. The present study aimed to evaluate irrigation regimes (I1: full-watered; I2: rainfed condition; I3: interruption of irrigation at the flowering stage; I4: interruption of irrigation at the seed setting stage) and spraying (S1: foliar spray with distilled water; S2: foliar spray with 250 Mm of thiamin; S3: foliar spray with 1 Mm of ascorbic acid; S4: foliar spray with 100 ppm of silicon dioxide nanoparticles; S5: foliar spray with 500 ppm of zinc oxide nanoparticles) on the morpho-physiological traits of rapeseed (Brassica napus L.). The accelerated maturity and the lowest seed yield were recorded under I2 (1,389 kg ha-1), which was 38 % lower than the yield obtained under I1. The greatest decrease in the evaluated traits, such as chlorophyll (48 %), leaf relative water content (25 %), number of pods per plant (56 %), plant height (29 %) and canopy spread (24 %), was recorded under I2. The lowest plant performance was related to I2 and I3, respectively. The foliar treatments did not mitigate the disruptive effects of I3 on plant growth; however, under I1, the use of silicon nanoparticles, zinc oxide nanoparticles and thiamine increased some seed yield components.

KEYWORDS: Brassica napus L., irrigation regimes, water stress.