Guide for Identification and Management of Diseases of Cucurbit Vegetable Crops
Cucurbits are generally well adapted for culture in Oklahoma and are grown both commercially and in home gardens throughout the state. However, diseases can limit the quality and number of cucurbit fruits produced, and diseases can directly attack the fruit, rendering it unmarketable. Diseases indirectly reduce yields by killing plants prior to harvest; cause defoliation, which reduces fruit size and quality; and exposes fruit to sun scald. Cucurbit crops are subject to biotic disease caused by pathogens that include fungi, bacteria, viruses and nematodes. Abiotic disease are caused by environmental conditions, such as soil imbalances (nutrients or pH), moisture imbalances and chemical injuries (herbicides and other chemicals) also may injure cucurbits.
The purpose of this publication is to aid in the identification of important diseases of cucurbits in Oklahoma and to provide general guidelines for their management. Correct disease identification is the first step in effective management. Incorrect identification can lead to the implementation of ineffective management practices and crop failure. For example, diseases caused by bacteria or viruses are not controlled with most fungicides. Furthermore, some fungicides will control one fungal disease, but not another. Cucurbit growers should learn to recognize the more common diseases by their symptoms, become aware of conditions that favor diseases and have sufficient knowledge of disease development to select appropriate management practices. Some diseases are easy to identify in the field, while others are more difficult. The OSU Plant Disease and Insect Diagnostic Laboratory offers disease diagnosis as a service to commercial growers and homeowners. Samples can be submitted to the laboratory through local county OSU Extension offices.
Read the full version of E-929 - Guide for Identification and Management of Diseases of Cucurbit Vegetable Crops.