Abstract:   As affected by the seasonal monsoon climate, the pineapple [Ananas comosus (L). Merr.] plants cultivated in Guangdong, Guangxi and Fujian are usually damaged in winter and early spring due to the low temperature and cold wave from the north. After being encountered with the cold season, the leaves turn greensick, and even, the whole pineapple plant is wilted. What’s more, when the pineapple shoot point is suffered from the cold frost and cold rain, the newly growing leaves would be rotted, and particularly worse, the plant would be died. Field culture practices have indicated that covering the plant with plastic net or film is effective to cold-proof for the pineapple in winter. Nevertheless, there is little information published to date regarding the comparative efficiency of different covering practices on anti-chilling for pineapple in winter. Accordingly, in this paper, at the pilot pineapple orchard in Guangdong Province, three covering-practice treatments with black plastic net, gray plastic net and white plastic film were performed to investigate the efficiency on the prevention of pineapple plants from chilling by comparing with CK (no covering), which was arranged as a random block design with three repetitions. For the three covering-practice treatments, the black plastic net, gray plastic net and white plastic film which were uniformly 7 m in length and 1.5 m in width, were directly covered on the pineapple plants. To clearly and easily distinguish the three treatments in this present work, the three covering-practice treatments were referred to as BN, GN and WF, respectively. In this work, the micro-environmental factors outside canopy between pineapple rows (air temperature and humidity as well as light intensity), the growth properties of pineapple plants and fruits, as well the fruit quality aspects of the three covering-practice treatments were compared with CK. The results showed that the number of newly growing leaves and the elongation of leaves of pineapple plants were increased under the treatments of BN, GN and WF(P<0.05). The air temperature was not significantly affected by BN, GN and WF treatments, while the air humidity was increased and light intensity was decreased(P<0.05). The individual size of pineapple fruit was not significantly influenced by BN, GN and WF. TSS (Total soluble solid) was decreased and titratable acid content was increased by BN(P<0.05). The b* value (Yellow) of flesh color of pineapple fruit pulp was decreased by covering with GN and WF(P<0.05). The aromatic production of pineapple fresh fruit was not significantly affected. For the pineapple plant at vegetative growth period, it was promoted in growth by the three treatments, especially by WF covering-practice. With respect to the pineapple fruit, it was slightly influenced by GN and WF covering treatments in growth and fruit quality. This work would contribute to provide a reference for preventing the pineapple from chilling in winter.

Key words:  Covering-practices, Anti-chilling, Pineapple, Growth, Quality, Micro-environmental factors