Physiological response of post emergence application of herbicides in maize [Zea mays (L.)]

Abstract

A field experiment entitled was conducted at Research Farm, AICRP on Forage Crops, Department of Agronomy and Plant Physiology, JNKVV, Jabalpur (Madhya Pradesh) during Kharif season of the year 2018-19. The treatments comprised of 7 weeds control methods viz. application of herbicides Tembotrione @120g ha-1, Topramezon @35g ha-1, Tembotrione+Atrazine @120g+250g ha-1, Topramezon+Atrazine @35g+250g ha-1, 2,4-D @500g ha-1, two hand weeding, and another one kept untreated (weedy check) in each replication. The research experiment was laid out in a randomized blockdesign replicated thrice. The highest total dry weight was recorded in treatment T6- (Hand weeding) and T6 alsohad highest magnitude of most of the physiological parameters i.e. LAI (3.27), LAD (69353.77), CGR (0.083) and SLW (0.00738) whereas, maximum value of average RGR (0.098), NAR (0.00165) and SLA (213.90) recorded in treatment T7- Control (weedy check). The major yield components were also found superior for number of cobs plant-1, cob length, cob girth, number of grains cob-1, cob weight, 100 grain weight including high biological yield and seed yield and highest harvest index in the hand weeding treatment (T6) due to better control of weeds which resulted into better photo assimilate transportation towards the sink. It is also concluded from the economic analysis. The herbicidal treatment Topramezon+Atrazine @35+250g ha-1 was found superior in benefit: cost ratio and economic as compared to other treatments.