Causes of Secondary Growth in Potatoes and Control Methods

Nilka County has a narrow and long terrain with a cool climate, suitable for the growth of cold-loving crops. Potatoes have always been the dominant main crop in the area. Through years of in-depth investigation and research, technicians have identified the causes of secondary growth in potatoes and the corresponding solutions.

I. Secondary growth in potatoes

In early August 2003, in Village 5 of Nilka Town, 1.3 hectares of potatoes sown in late April had tubers that had swollen to the size of eggs, the buds on the new tubers sprouted, and small tubers the size of a thumb grew out, while the new tubers grew and aged, no longer continuing to expand. This phenomenon also occurred in other potato plots with similar cultivation conditions.

II. Causes of secondary growth

1. Growth habits

During the growth and development of potatoes, when encountering high temperatures above 29°C, the stems and leaves grow excessively, the tubers stop growing and gradually age. Afterwards, if rainfall or watering occurs, the external conditions such as temperature and humidity required for tuber growth and development are satisfied, which can cause the buds on the tubers to sprout, resulting in the secondary growth phenomenon of new tubers.

2. Climatic conditions

Since July 2003, the climate in our area has alternated between clear and rainy, with temperatures fluctuating between 5 and 32°C, which is extremely abnormal. This is the main cause of secondary growth in potatoes.

3. Management measures

During the potato growth process, excessive application of nitrogen fertilizer and foliar fertilizers such as Nongdazhuang and tuber swelling agents in the early stage resulted in sufficient or even excessive water and nutrients, promoting excessive leaf growth and overly vigorous plant growth, leading to excessive plant density. Corresponding management measures were not taken in time, thereby inhibiting tuber expansion and growth.

III. Solutions

1. Pay attention to sowing density

A row spacing of 70×20 cm is more suitable.

2. Strengthen cultivation management

Remove overly dense and excessive leaves at the root and stem parts of the plants to alleviate the problems of excessive plant density and high nutrient consumption. Timely apply quick-acting phosphorus and potassium fertilizers, or 0.1% concentration of chlormequat, to inhibit excessive plant growth.

3. Earth up to raise the ridges

Remove the flowers at the top of the plants to promote tuber growth.