An optimal staggered canopy system for high yield cultivation of cotton and light distribution in the canopy

摘要

Staggered canopy system is an effective planting practice for high yield by maximizing light penetration into the canopy of cotton (Gossypium hirsutum L.) plants. Compared with traditional cropping practices, this system produces higher yields in general. A staggered c anopy system is constructed by planting two cultivars of different shoot architectures to form a canopy of two leaf layers. Field experiments of four treatments were carried out to determine the optimal pattern of staggered canopy. Solar radiations at different heights in the canopies were measured at a vertical interval of 20 cm between and within rows, using a digital light intensity meter. The optimal planting pattern for high yields consisted of two rows of tall plants bracketing a row of short plants with a wide spacing of 100 cm around the rows of short plants, which formed a staggered canopy. The available photosynthetic photon flux density in the staggered canopy was higher than in the canopy of conventionally planted field after the canopies were closed. The staggered canopy system allows more light penetration into the canopy than the conventional, where light was deducted sharply by an excessively dense canopy. In addition, wind speeds and CO_2 concentrations inside the staggered canopy were greater than those in the conventional. The staggered canopy has an improved canopy structure compared to a conventional planting practice.