Impact of Pests on Cereal Grain and Nutrient Yield in Boreal Growing Conditions

Katja Kauppi,Heikki Jalli,Pentti Ruuttunen,Erja Huusela,Marja Jalli,Laura Alakukku,Janne Kaseva,Ari Rajala

doi:10.3390/agronomy11030592

Katja Kauppi, Heikki Jalli + Show 6 more

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https://doi.org/10.3390/agronomy11030592

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Abstract

The effect of weeds, plant diseases and insect pests on spring barley (Hordeum vulgare) and spring wheat (Triticum aestivum) grain and nutrient yield was examined. Long-term field trial data was used to assess the impact of different pests on grain yield. In the absence of pesticides, fungal diseases caused the largest annual yield-reduction in spring wheat and spring barley, 500 kg ha−1 on average. Converting yield loss to nutrient yield loss this represented reductions of 8.1 and 9.2 kg ha−1 in nitrogen and 1.5 and 1.6 kg ha−1 in phosphorus, respectively. Likewise, it was estimated that weeds decrease the yield of spring barley and spring wheat for 200 kg ha−1, which means reductions of 3.7 and 3.2 kg ha−1 in nitrogen and 0.6 kg ha−1 in phosphorus, respectively. For insect pests yield-reduction in spring barley and spring wheat varied between 418 and 745 kg ha−1 respectively. However, because bird cherry-oat aphid (Rhopalosiphum padi L.) incidence data was limited, and aphids are highly variable annually, nutrient yield losses caused by insect pests were not included. Based on the current study, the management of weeds, plant diseases and insects maintain cereal crop yield and may thus decrease the environmental risks caused by unutilized nutrients.

Highlights

In the Boreal region the growing conditions are unique
Based on the current study, the management of weeds, plant diseases and insects maintain cereal crop yield and may decrease the environmental risks caused by unutilized nutrients
Even though pests and their effect to crop yield has been an object of interest in agricultural studies for decades, the effect of pests on nutrient yield harvested in grain yield is seldom reported

Summary

Introduction

In the Boreal region the growing conditions are unique. In Finland over half of the cereal grain cultivation area is located between 60◦ N and 65◦ N [1]. Longer growing seasons may affect the incidence of pests (weeds, insects and plant diseases): plant disease risk may increase due to accelerated and more aggressive plant pathogen evolution and a larger number of infection cycles [4,5] while longer and warmer growing seasons constitute ideal conditions for pests to thrive [6,7,8]. Pests have a negative effect on crop yield, and at the worst, some pests may destroy entire crops leading to a total loss of crop yield. According to Oerke [9], weeds can cause high yield losses (up to 34%) in spring wheat (Triticum aestivum), rice (Oryza sativa), maize (Zea mays), potatoes (Solanum tuberosum), soybeans (Glycine max) and common flax (Linum usitatissimum), whereas insects and plant diseases cause lower but still substantial average yield losses (18% for insects and 16% for plant diseases) for the same crops. There are differences with different crop densities: Lutman et al [12]

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