Jujube rust, also known as Chinese date rust, has become a serious problem in jujube-growing regions in recent years, leading to significant crop losses and severe damage to local jujube production. This disease typically appears during the fruit enlargement stage, causing excessive leaf drop, shriveled fruits, and a decrease in pulp sugar content, making the fruits less palatable. The impact of jujube rust not only reduces yield but also degrades fruit quality, directly affecting farmers' income. In severe cases, early leaf fall can lead to secondary sprouting and flowering, which negatively affects the following year's harvest. Therefore, it is essential to implement comprehensive prevention and control measures early on to minimize the damage caused by this disease.
1. **Chemical Control**
From early July to late August, apply fungicides every 10 to 15 days. Suitable options include 1000-fold diluted copper oxychloride or 1000-fold diluted mancozeb, or 200-fold Bordeaux mixture, along with 70% thiophanate-methyl diluted to 800 times. These treatments are effective in controlling the spread of jujube rust and reducing its impact on the crops.
2. **Scientific Fertilization**
Studies show that jujube trees grown in poor soil with weak growth and low yields are more susceptible to rust. To improve tree health and resistance, proper fertilization is crucial. Apply 2,000 to 3,000 kg of high-quality organic manure per acre as a base fertilizer. During the growing season, spray foliar fertilizers every 15 days—such as 800-fold fruit dew or PBOG at 1500 times, borax at 400 times, or a mix of Meifeng or Qirui amino acid fertilizer (400 times) with urea (300 times). Additionally, apply top-dressing fertilizers rich in nitrogen, phosphorus, and potassium, with approximately 0.71 to 1.5 kg per tree annually, depending on its age and productivity.
3. **Water Management in the Rainy Season**
As the saying goes, "sweet pears and jujubes," but long-term waterlogging in jujube orchards can cause premature fruit drop and root death, increasing the risk of rust. It is important to drain excess water from low-lying areas during the rainy season to reduce the likelihood of disease occurrence and protect the overall health of the trees.
4. **Proper Pruning**
Overly dense planting and vigorous growth can hinder air circulation and sunlight penetration, weakening the tree’s ability to resist diseases. Prune judiciously to improve ventilation and light exposure. Focus on removing thin branches, excessive new shoots, and overly dense inner growth to reduce nutrient competition and promote better fruit set and quality. Regular pruning enhances the tree’s resilience against rust and supports long-term healthy development.
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