Assessing the Performance of Maize (Zea mays L.) as Trap Crops for the Management of Sunflower Broomrape (Orobanche cumana Wallr.)

Xiaoxin Ye,Manyun Zhang,Meng Zhang,Yongqing Ma

doi:10.3390/agronomy10010100

Abstract

Sunflower broomrape (Orobanche cumana Wallr.) is a weedy root parasite that causes huge damage to sunflower (Helianthus annuus L.). Trap crop can stimulate parasitic seed germination without attachment in trap crop, and it was considered as economic methods for controlling the parasite. In this study, co-culture and pot experiments were conducted to assess the allelopathic activity of maize (Zea mays L.) to stimulate broomrape seeds germination and to evaluate the performance of maize rotation for reducing sunflower broomrape infection. All the tested maize cultivars could induce sunflower broomrape germination, and the most active maize cultivar was N314, which induced approximately 40% broomrape seeds germination. Rotation of maize significantly reduced broomrape infection on subsequent sunflower and increased sunflower biomass. After cultivated N314 for 3 years, broomrape attachment on sunflower was the lowest (0.8 attachment plant−1), and the dry mass of sunflower shoot (28.7 g plant−1) was approximately twice higher than the sunflower without previous crop. The effectiveness of broomrape management was significantly different among various maize cultivars. Meanwhile, the differences among cultivars were decreased with the years of maize cultivated prolonged. Our results confirmed that maize was significantly effective in reducing the sunflower damage caused by sunflower broomrape and suggested that maize rotation could be included in the integrated management of sunflower broomrape.

Highlights

Broomrapes (Orobanche and Phelipanche spp.) and witchweeds (Striga spp.) are holoparasites that completely depend on the host, due to the lack of chlorophyll and functional roots
The broomrape seeds germinated at a high rate (89.5%) after treating with GR24, whereas none of them germinated when treated with sterilized vermiculite just wetted with water. These data indicated that distilled water did not induce sunflower broomrape germination and that interference of sterilized vermiculite was eliminated
All the seedlings of commercial maize cultivars co-cultured with broomrape induced germination, but the subsequent attachment of broomrape on their roots did not occur (Figure 1), which demonstrates that maize is a non-host for sunflower broomrape

Summary

Introduction

Broomrapes (Orobanche and Phelipanche spp.) and witchweeds (Striga spp.) are holoparasites that completely depend on the host, due to the lack of chlorophyll and functional roots. Sunflower broomrape (Orobanche cumana Wallr.) exhibits a restricted host range and essentially attacks sunflower (Helianthus annuus L.). It spreads over a vast area from central Asia to south-eastern Europe [1]. It is present in large parts of northern China and has become a serious constraint, causing substantial yield losses of sunflower [2]. Areas of sunflower affected (and yield losses) have been estimated at about 20,000 ha (20–50% losses) in China and in Bayan Nur City, Inner Mongolia.

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Discussion

Conclusion