Vineyard growth and grape yield can be significantly reduced by weeds, especially when these are located in the under-vine zone. Traditional weed management consists of recurrent tillage, which is associated with soil erosion and high fuel consumption, or herbicide applications, associated with damage to the environment and human health. In order to find alternative weed management methods, three field trials were carried out in Raimat (Lleida, NE Spain) with the aim of evaluating the suppressive effect of four mulches against weeds. Treatments included (1) straw mulch of Medicago sativa L., (2) straw mulch of Festuca arundinacea (L.) Schreb, (3) straw mulch of Hordeum vulgare L., (4) chopped pine wood mulch of Pinus sylvestris L., (5) mechanical cultivation and (6) herbicide application. The results showed that all mulches were efficient at controlling weeds (75%). In this way, pine mulch stood out above the straw mulches, as it achieved high soil cover during the three growing seasons of the study (>80%), with weed coverage values under 18%. This, together with the multiple benefits of mulches (improvements in the water balance and increases in soil organic matter, among others), make them a sustainable tool to be considered as an alternative to traditional under-vine weed management in vineyards.

Conyza bonariensis (L.) Cronquist is a widespread noxious weed with high fecundity, associated with no-till systems such as vineyards and other perennial crops in Mediterranean climates. Seeds germinate in staggered flushes, which leads to a great variation in the growth stage between individuals in the same field, and chemical control becomes challenging. Besides, Conyza species have evolved resistance to herbicides worldwide, particularly to glyphosate. Even though tillage is expected to provide weed-free fields, it negatively affects vineyards, causing erosion, loss of soil structure and a reduction in organic matter or vine growth (shallow roots can be affected), among other effects. Fuel consumption of this management is also very high because recurrent interventions of in-row tiller are required. In this context, bioherbicides, defined as environmentally friendly natural substances intended to reduce weed populations, are a potential tool for integrated weed management (IWM). In this work, the herbicidal effect of the following six products is tested on a glyphosate-resistant C. bonariensis population present in commercial vineyards: T1, mixture of acetic acid 20% and the fertilizer N32; T2, mixture of potassium metabisulfite and pelargonic acid 31%; T3, pelargonic acid 68%; T4, humic-fulvic acid 80%; T5, hydroxy phosphate complex; and T6, potassium metabisulfite. The results showed high field efficacy for T1 and T4 (>80% biomass reduction). For the rest of the products, high efficacy was obtained only in dose–response greenhouse experiments. The present work demonstrates the potential of certain bioherbicide compounds to manage herbicide-resistant weed species, such as C. bonariensis. Therefore, bioherbicides could be successfully incorporated into vineyards for IWM.

The implementation of cover crops in vineyards is an environment‐friendly soil management technique that has several advantages, including weed suppression. The effectiveness of the management depends on the characteristics of both the weed community and the cover crop species. The objectives of this study were to evaluate the dynamics of Cynodon dactylon patches and the rest of the weed community composition under five different cover crops (four grasses and one dicotyledonous species) in a commercial vineyard in Spain: (1) the perennial Festuca arundinacea and the annual species (2) Hordeum vulgare, (3) Vulpia ciliata, (4) a mixture of Bromus species and (5) Medicago rugosa. The annual species were sown in November every year after tillage (from 2015 to 2018) and shredded in June, while F. arundinacea was sown in 2015 and shredded in June and in November every year. Results showed that cover crop species affected C. dactylon soil coverage and frequency across the field. After three seasons, F. arundinacea and H. vulgare were the best cover crops which controlled C. dactylon, resulting in the lowest weed coverage of 4.6% and 3.0% respectively. Although the expansion of the weed was restrained by cover crops, the soil tillage prior to sowing the annual species spreads the rhizomes and stolons to weed free areas of the field. Canonical Correspondence Analysis (CCA) showed that the weed community composition varied depending on the cover crop species, revealing the importance of its management in the weed assemblage.