Abstract:

To investigate the response of various nutrient elements in ‘MD-2’ pineapple fruit to different irrigation amounts in the dry season, and to provide data and theoretical basis for the scientific formulation of its dry season water management measures, this study was conducted with the ‘MD-2’ pineapple grown under natural rainfall in field as the research object, and an experiment was designed with four irrigation amount gradients [20 mm (W1), 50 mm (W2), 100 mm (W3), 150 mm (W4)], and with no irrigation as the control (0 mm). We analyzed the N, P, K, Ca, Mg, Fe, Cu and Mn contents’ change in ‘MD-2’ pineapple fruit under different irrigation levels in the dry season. The results showed that: the increase of irrigation amount was beneficial to the increase of the fresh weight and dry matter weight of ‘MD-2’ pineapple fruit. Both the fresh weight (797.42 g) and dry matter weight (99.14 g) of W4 were the largest. The overall performance of the contents of all nutrient elements in ‘MD-2’ pineapple fruit was K> N> Ca> P> Mg> Mn> Fe> Cu, in which, K content was the highest, followed by that of N and Ca, and the Cu content was the lowest. The K content increased with the increase of irrigation amount in fruit, but the Ca, Mg and Mn contents decreased with the increase of irrigation amount, while the N, P, Fe and Cu contents under W2 were the largest. The increase of irrigation amount promoted the accumulation of K in fruit, but inhibited the accumulation of Mg in fruit, while the accumulation amounts of N, P, Fe, Cu, Ca and Mn in pineapple fruit reached the maximum value under W2. Taking into account the growth of fruit and the change characteristics of nutrient elements’ contents and accumulation amounts, irrigation in the dry season is essential. According to the actual rainfall, proper adjustment of irrigation (W2) to keep the total water supply at about 300 mm is beneficial to the accumulation amounts of dry matter in ‘MD-2’ pineapple fruit, and can significantly increase the contents of nutrient elements in ‘MD-2’ pineapple fruit. It ensures sufficient and balanced supply of nutrient elements in pineapple fruit to achieve the purpose of high yield, high efficiency and high quality.

Key words: irrigation amount, nutrient elements, ‘MD-2’ pineapple, fruit, dry season, content