Wilting is the loss of rigidity of non-woody parts of plants. This occurs when the turgor pressure in non-lignified plant cells falls towards zero, as a result of diminished water in the cells. Wilting also serves to reduce water loss, as it makes the leaves expose less surface area. The rate of loss of water from the plant is greater than the absorption of water in the plant. The process of wilting modifies the leaf angle distribution of the plant towards more erectophile conditions.

उकठा रोग (Wilting) में पौधों की पत्तियाँ और मुलायम भाग सूखने लगते हैं और उनमें दृढ़ता नहीं रह जाती। यह रोग अरहर, गन्ना, चना आदि बहुत से पौधों में होता है। इसके बहुत से कारण हो सकते हैं।