Effect of Nitrogen and Potassium Fertilization and Weed Control Treatments on Wheat Productivity and Associated Weeds under Saline Soil Conditions in The Northern Delta of Egypt

Abstract

Two field experiments were conducted, on a clay saline soil, at El-Serw Agricultural Research Station, AgriculturalResearch Centre, at Damietta Governorate, Egypt, during 2013/2014 and 2014/2015 winter seasons, to study the effect ofnitrogen and potassium fertilization and some weed control treatments on wheat growth, grain and straw yields,photosynthetic pigments, protein of grains and anatomical features of flag leaf of wheat plant (Triticum aestivum, L.),Sakha 93 cultivar and associated weeds. The experiments were carried out in a split-split plot design, with four replicates.Main plots were assigned to nitrogen applications (0, 45 and 90 N kg fed-1) (fed = 4200 m2). The sub-plots were allocatedto potassium treatments as follows: 0, 24 and 48 K kg fed-1. While, the sub-sub plots were allocated to weed controltreatments [Pallas (pyroxsulam) Atlantis (mesosulfuron), hand-weeding once, at 45 days after sowing and untreatedcheck].The results showed that increasing nitrogen fertilization rates up to 90 kg N fed-1 and potassium rate up to 48 kg Kfed-1 increased the total dry weight of broadleaved and grass weeds after 60 and 90 days of wheat sowing, wheat plantheight (cm), dry weight (g), photosynthetic pigments, grain and straw yields (t fed -1) and protein of grains while, usingPallas (pyroxsulam) and, Atlantis (mesosulfuron) herbicides and hand-weeding once, gave the highest results of previousparameters, respectively, except for the total dry weight of broadleaved and grass weeds, which occurred in a highdecrease after 60 and 90 days of wheat sowing. On the other hand, the interaction between nitrogen and potassium levels,with weed control treatments, was not significant in all characters of wheat plant and total dry weight of weeds, except forwheat grain and straw yields, which was significantly increased in both seasons, and protein yield of wheat grain in thefirst season. Also, the study showed that applying 90 kg N fed-1 + 48 kg K fed-1 + Pallas (Pyroxsulam) herbicide gave thehighest wheat grain and straw yields compared to (N0 + K0 + untreated check) being (329 and 316%) and (363 and 354%)and for (N90 + K48 + untreated check) to (86 and 87%) and (86 and 87%) in the first and the second seasons,respectively. Thus, it was preferred to use 90 kg N fed-1 + 48 kg K-1 + Pallas (Pyroxsulam) herbicide to get an economicwheat production with high quality, which was grown in saline soil in the northern Delta of Egypt.Anatomical study on the flag leaf of wheat plant, after ninety days subjected to high levels of nitrogen and potassiumfertilization with weed control treatments gave a big improvement, caused a positive impact on the growth of plants, andimprove all traits under study. These results suggest that elimination of weeds by Pallas (pyroxsulam) and, Atlantis(mesosulfuron) herbicides and hand-weeding once could minimize weed competition to wheat plant and consequentlyimproved photosynthetic fluid assimilates in the wheat phloem, on one side and in other side nutrient uptake from soil andconsequently promoted the growth of wheat plants.