Causes of Fruit Cracking in Greenhouse Tomatoes and Preventive Measures

Tomatoes are both a vegetable and a fruit, rich in nutrients and delightfully flavorful. However, many growers report that cracking—either sporadic or widespread—is a common issue during cultivation. Fruit cracking is a widespread problem, particularly in greenhouse production, and it can severely compromise yield and quality, thereby reducing economic returns.

Causes of tomato fruit cracking:

1. Variety: In northern greenhouses, it is recommended to select mid- to late-maturing varieties that are tolerant of low temperatures and weak light, while avoiding those with large fruit size, thin skin, and a thick corky layer. Choosing the right variety is key to achieving high yields and superior-quality tomatoes.

2. Improper management of water and fertilizer: During flowering, low temperatures can impair leaf photosynthesis and limit root nutrient uptake, leading to nutrient deficiencies in floral organs and the development of deformed flowers, which may later predispose the fruit to cracking.

3. Humidity: As temperatures gradually decline in autumn, relative humidity inside greenhouses tends to rise, leading to more frequent condensation. To reduce indoor humidity, growers often rush to ventilate and dissipate moisture. However, if outdoor winds are too strong, the rapid evaporation of surface moisture can cause tomatoes to lose water quickly, resulting in cracked skin and fruit splitting.

Integrated management and control measures:

1. Prioritize varieties that are well-suited to local cultivation, meet local market demand, and exhibit strong stress tolerance.

2. During seedling cultivation and flowering, nighttime temperatures should not remain excessively low for extended periods. Daytime temperatures should be around 25°C, and the diurnal temperature range should not exceed 10°C.

3. Direct sunlight on the fruits should be avoided; pruning and removing side shoots can be carried out appropriately, ensuring that vegetative leaves remain in positions that provide shade for the fruits. When necessary, shading materials such as shade nets may be used.

4. Apply additional bio-organic fertilizer in the field to enhance soil aeration, improve its water‑ and nutrient‑retention capacity, and increase its resilience to both excessive moisture and severe drought, thereby helping the soil maintain a favorable ecological environment and promoting robust root development. For compound fertilizers, choose a humic‑acid‑based balanced formulation, such as a 17‑17‑17S product containing humic acid, and avoid over‑applying nitrogen to prevent interference with calcium uptake by tomato plants. In the later stages of fruit development, regularly spray water‑soluble fertilizers rich in boron and calcium—such as Nongda’s Golden Dew or Heizefeng—to reduce blossom‑end rot caused by deficiencies in these nutrients. Apply such foliar sprays approximately once a week; typically two to three applications are sufficient to effectively prevent fruit cracking in tomatoes.

5. During tomato flowering, maintain nighttime temperatures above 10°C; during fruit set and fruit‑expansion stages, apply supplemental fertilizer as needed. Throughout the flowering and fruiting period, apply via irrigation or drip fertigation 2 bottles of Qingkuli, 2 bottles of Amino Oligosaccharide, 1 bag of JunChongFeng, and 1 bag of Fulvic Acid granules, 1–2 times. This helps replenish the nutrients required for flowering and fruiting while preventing and controlling diseases and pests.