Foliar spray of Rooyesh-No fertilizer on yield and agronomic characteristics of rice cv Hashemi

Foliar spray of fertilizers is an effective fertilizing method for enhancing growth in plants through fast absorption and speeding the transport of assimilates from leaves to the reproductive organs. Rice (Oryza sativa L.) after wheat is the most important crop in Iran and has a special place in people's food basket. Increasing rice production needs the development and release of high yielding cultivars and management of agricultural practices especially proper fertilizer application. This experiment was aimed to evaluate the effect of foliar spray of Rooyesh-No liquid fertilizer on yield, yield components and agronomic characteristics of rice cv 'Hashemi'.

This experiment was carried out as a randomized complete block design with three replications using in 2017 and 2018. Fertilizer treatments included T0: control (No fertilizers applied), T1: application of base fertilizers: (NPK), T2: one-time foliar application of liquid fertilizer with no application of base fertilizers, T3, T4, T5, T6, T7 one, two, three, four and five times application of fertilizer +NPK, respectively. Measured parameters were panicle length, plant height, number of tillers, flag leaf area, length of flag leaf, plant dry plant weight, number of grains, percent of filled grains, yield, harvest index, total chlorophyll content, chlorophyll a and b content, carotene, SPAD value and leaf color.

foliar spray of fertilizer had a significant effect on all of the studied traits except for panicle length, and plant dry weight. Foliar spray resulted in darker leaves which was attributed to increase in chlorophyll content. Although application of base fertilizer could provide critical SPAD value (37), but foliar spray increased the SPAD values to higher than 40. Foliar spray also increased the number of filled grains. Thousand grain weight was also higher with foliar spray and reached from 25.1g in T0 (no fertilizer treatment) to 29.0g in two times spray treatment (T4). In this experiment foliar spray had positive effects on grain yield, percent of filled grain, 1000 grain weight, SPAD number, leaf chlorophyll content, leaf color, harvest index and plant biomass. Highest grain yield (4156.0 kg/ha) and performance were observed with two-times foliar application of fertilizer (T4).

Foliar spray increased overall plant growth and grain yield through fast absorption of nutrients and increase of chlorophyll content. An important finding of this experiment was the confirmation of the positive effect of liquid fertilizers even in the presence of base fertilizers. Keywords: Yield, Grain filling, Plant nutrition, Fertilizer spray