Greenhouses, also known as glasshouses, are designed to allow light transmission, retain warmth (or generate heat) for plant cultivation. They enable the growth of plants during unsuitable seasons, thereby extending the growing period. They are used for cultivating or propagating vegetables, flowers, trees, and other plants that thrive in warm conditions during cold seasons. What should be taken into account during their cultivation?

1. For greenhouse structures, steel pipes should be used as the material. Greenhouse construction manufacturers should set up the greenhouse structure frame before the frost season, ensuring good orientation in the north-south direction, with the greenhouse body having a ridge aligned with the north-south direction. In Xu Jian's parameters, the ridge is 1.8 meters high, the sides are 1.2 meters high, and the width is 8 meters. The cost of greenhouse construction can be determined, with the length typically ranging from 60 to 800 meters.

2. The potato harvest product chosen for the land selection is the underground tuber. To achieve high yields, Liaoning Province selects flat, deep, fertile, loose, and easily drained loam and sandy loam land for greenhouse construction. The land should have been fallow for more than 3 years to benefit disease prevention.

The selection of high-quality potato varieties is affected by viruses, severely limiting yield and growth improvements. Therefore, greenhouse production should opt for virus-free and early-maturing varieties such as Dongnong 303, Feiwu Ruita, and Zihua Bai.