Viticulture requires fewer agrochemicals than many other field crops, partly because such a high proportion of vines are grown in warm, dry summer environments in which fungal diseases are relatively rare, and also because vines require fewer fertilizers than most other crops (see vine nutrition). Vines grown in humid, warm summers may require as many as ten or more sprayings, however. Vine-growers, like other farmers, are in general becoming less reliant on agrochemicals as a result of increased environmental concerns (see sustainability), and as alternative approaches become available. Some diseases, notably botrytis bunch rot, develop tolerance to the repeated use of some chemicals, and so their continued use is now subject to resistance-management strategies. Alternative approaches may take the form of integrated pest management (IPM) programmes, which aim to apply chemicals more rationally, or the adoption of some form of sustainable, organic or biodynamic viticulture, which aim to minimize the use of agrochemicals.