Efficacy of herbicides time application for weed control in rain-fed Lentil (Lens culinaris Medik.)

IntroductionRain-fed Lentil (Lens culinaris Medik.) is vulnerable to weed competition because of its tiny stature, slow establishment, and limited vegetative growth. Weed control is necessary for maximum seed yield and seed quality. Crop yield losses are primarily a result of competition with weeds for nutrients, moisture and space. Therefore, weed control at this period plays an important role to gain high roduction. Although the vast majority of lentil production is under rain-fed conditions, there is a little published information on weed control with herbicides in rain-fed lentils. Herbicides due to efficiency and expense savings play a essential role in weed control. The purpose of this research was to determine the best time to application effective herbicides in weeds control for the maximum rain-fed Lentil production in Khorramabad. Materials and MethodsThe Lentil (Lens culinaris Medik.) field experiment was carried out as split plot based on complete randomized block design with three replications during 2017-2018 in Khorramabad (48.21°E, 33.29°N, 1170 m above sea level, 450 mm average yearly precipitation) Iran. The following herbicides were used: Oxyfluorfen (EC 24%) 1 Li ha-1, Isoxaflutole (SC 480) 200 Ml ha-1, Flumetsulam(WG 800) 20 g ha-1, Metribuzin (WP 70%) 500g ha-1, Pendimethalin Aria(EC33%) 4 li ha-1, Pendimethalin Prowl (CS45.5%) 4li ha-1, Imazethapyr (SL10%) 350 ml ha-1 and Pendimethalin prowl 2li ha-1plus Imazethapyr 350 ml ha-1. Herbicide applicatioin time at 3 levels; IAP application (Immediately after planting), PRE application and IBCE (eraly post herbicide application at fourth lentil node stage) was assigned to the main and sub plots respectively. The fields were in wheat cultivation in the year before the experiments. The soil at the test sites was a silty loam with a pH of 7.9 and organic matter of 1.11%. Lentil was sown at a density of 75 kg seed ha-1 by hand on December 21, 2017. Herbicides were sprayed with an electric knapsack sprayer MATABI (calibrated to deliver 300 L ha-1. In order to evaluate the effect of treatments on weeds density and biomass, at the beginning of lentil flowering, sampling was done from a surface of 0.3 m-2 area and weed density and weed biomass recorded. At lentil physiological maturity, the yield and yield components were measured by harvesting lentil plants from a 1-m2 area in each plot (Izadi & Maghsoudi, 1400). The data were subjected to the analysis of variance using SAS. Means were compared