Perennial Cotton Ratoon Cultivation: A Sustainable Method for Cotton Production and Breeding

Abstract

Cotton production is challenged by high costs with multiple management and material inputs including seed, pesticide, and fertilizer application. The production costs can be decreased and profits can be increased by developing efficient crop management strategies, including perennial cotton ratoon cultivation. This review focuses on the role of ratoon cultivation in cotton productivity and breeding. In areas that are frost-free throughout the year, when the soil temperature is suitable for cotton growth in spring, the buds of survived plants begin to sprout, and so their flowering and fruiting periods are approximately 4-6 weeks earlier than those of sown cotton. Due to the absence of frost damage, the ratoon cotton continues to grow, and the renewed plants can offer a higher yield than cotton sown in the following season. Moreover, ratoon cultivation from the last crop without sowing can help conserve seeds, reduce labor inputs, and reduce soil and water loss. In this review, the preservation of perennial cotton germplasm resources, the classification and genome assignment of perennial species in the cotton gene pools, and effective strategies for the collection, preservation, identification, and utilization of perennial cotton germplasms are discussed. Ratoon cultivation is the main driver of cotton production and breeding, especially to maintain male sterility for the utilization and fixation of heterosis. Ratoon cultivation of cotton is worth adopting because it has succeeded in Brazil, China, and India. Therefore, taking advantages of the warm environment to exploit the indeterminant growth habit of perennial cotton for breeding would be an efficiency-increasing, cost-saving, and eco-friendly approach in frost-free regions. In the future, more attention should be given to ratooning perennial cotton for breeding male-sterile lines.

Keywords: Gossypium (cotton); heterosis; indeterminate; male-sterile; stub.

Figure 1

Classification of ratoon cotton based on cultivars, semiwild species, wild/feral species, and chromosome ploidy. The green boxes show the cultivated species, and the yellow boxes show the wild species.

Figure 2

The primary, secondary, and tertiary gene pools based on their genetic relationship with upland cotton. The primary, secondary, and tertiary cotton (Gossypium) gene pools are shown from the inside circle to the outer ring. The farther away the primary gene pool is the further the genetic approachability is from the tetraploids, and the richer the genetic diversity.

Figure 3

An overview of the seven main advantages of naturally grown semiperennial (semiwild) cotton lines compared to annual cultivars.

Figure 4

Ratoon cotton planted in the experimental field on the campus of Guangxi University, Nanning, China. Photos of the population (A) and a single plant (B) after the main stem is pruned.