Enhancing Potato Tuber Yield and Quality through Integrated Fertilization

Abstract

Developing healthy plants is necessary for maximum growth and this requires all essential nutrients to be supplied at optimal rates. So, two field experiments were conducted in a calcareous soil at Nubaria Agricultural Research Station, El-behera governorate, Egypt (Latitude 30o 54' 48.220 N, Longitude 29o 51' 50.634 E), during 2014/015 and 2015/016 winter seasons to assess the effect of potassium (K2SO4) and magnesium (MgSO4 7H2O) fertilizers applied separately or in combination on yield and some qualitative parameters of potato (cv. Alpha) tubers. The two experiments were laid out in a randomized complete block design with three replicates including fifteen treatments as follows: 0, 24 and 48 kg K2O fed-1 and 0, 5, 10 & 15 kg Mg fed-1.The last three treatments contained 2.5, 5 & 7.5 kg Mg fed-1 combined with 24 kg K2O fed-1 plus foliar application of 1% K2O + 0.63 % Mg. The obtained results show that the combination of both nutrients (K and Mg) as 24 kg K2O fed-1 plus 15 kg Mg fed-1 significantly increased number of tubers plant-1, tuber yield plant-1, medium sized tuber yield (35-55mm) and total tuber yield as well as tuber quality i.e. total carbohydrate % & starch %, tuber dry weight and N, P, K & Mg uptake in tubers over the control (zero K and Mg fertilizers). On the other hand, the highest large sized tuber yield (<55mm) was obtained under the treatment received 48 kg K2O fed-1 combined with 5 kg Mg fed-1 which did not differ significantly from treatment received 24 kg K2O fed-1 plus 7.5 kg Mg fed-1 accompanied by foliar spray of 1% K2O + 0.63 % Mg, whereas soil application of (24 kg K2O fed-1 plus 5 kg Mg fed-1) or (24 kg K2O fed-1 plus 7.5 kg Mg fed-1) accompanied by foliar spray of 1% K2O + 0.63% Mg recorded higher significant increases in leaf N content and dry matter % of tubers relative to control treatment with no significant difference between the two treatments. The highest values of P and K content in leaves were obtained when plants were treated with 48 kg K2O fed-1 solely, while applying 15 kg Mg fed-1 alone gave the highest significant value of Mg content in potato leaves.