Potassium Application Improves Grain Yield and Alleviates Drought Susceptibility in Diverse Maize Hybrids.

Sami Ul-Allah,Muhammad Naeem,Umar Farooq,Muhammad Ijaz,Farukh Nawaz,Abdul Sattar,Khalid Mahmood,Ahmad Sher,Umbreen Shahzad,Ahmad Nawaz

doi:10.3390/plants9010075

Abstract

Maize (Zea mays L.) is an important component of global food security but its production is threatened by abiotic stresses in climate change scenarios, especially drought stress. Many multinational companies have introduced maize hybrids worldwide which have variable performance under diverse environmental conditions. The maize production is likely to be affected by a future water crisis. Potassium (K) is a well-known macronutrient which improves the performance of cereals under abiotic stresses. In this field experiment, we assessed the influence of soil applied K on the productivity of diverse maize hybrids grown under well-watered and drought stress conditions. The study consisted of three K levels viz., control (no KCl), KCl at 50 kg ha−1, and KCI at 75 kg ha−1 factorally combined with two irrigation levels (i.e., normal recommended irrigation, well-watered condition, and half of the recommended irrigation, drought stress condition) and eight maize hybrids. Irrigation was kept in main plots, potassium in subplot, and maize hybrids in sub-subplots. The results revealed that performance of the maize hybrids was significantly influenced by all three factors, and the interaction of irrigation with potassium and irrigation with hybrids was significant; results being non-significant for all other interactions. Potassium application improved yield traits and water productivity under both normal and water stress conditions but effect was more prominent under water stress conditions than normal conditions. Potassium application also alleviated drought susceptibility of all maize hybrids. In all cases, the performance of maize hybrids was maximum under potassium application at 75 kg ha−1.

Highlights

Maize (Zea mays L.) is the third most important cereal for global food security after wheat and rice [1,2]
Potassium application had a significant effect on 1000-grain weight, grain yield, biological yield, water productivity, and drought susceptibility index
Maize hybrids differed for grain yield, biological yield, water productivity, and drought susceptibility index; results being non-significant for 1000-grain weight

Summary

Introduction

Maize (Zea mays L.) is the third most important cereal for global food security after wheat and rice [1,2]. Maize plays a productive role in a cropping system by producing good economic return to farmers and having higher yield potential, shorter growing period, and growing ability in varying environments. It serves as a cheaper feed source for livestock and its seeds are used in different agro-based industries. Plants 2020, 9, 75 is threatened by abiotic stresses, especially heat and drought [3,4,5,6] which in turn is threatening the global food security. At the early stage of water stress, losses are due to reduced growth, development, and CO2 fixation, while water stress at the reproductive stage leads to reproductive failure, less allocation of assimilates to the grains, and reduced grain filling period which results in shrunk grains [10,11]

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