Effects of different fertilization modes on the photosynthetic characteris-tics, yield and growth in hybrid hazelnut (Corylus heterophylla × C. avella-na)
【Objective】In this paper, the effects of four fertilization modes on the plant growth, yield, nut quality and photosynthetic characteristics of hybrid hazelnut (C. heterophylla × C. avellana) were studied through two years trial (2019—2020) in order to provide a theoretical basis for appropriate fer-tilization.【Methods】In this experiment, from 2019 to 2020, the fertilization tests with the hybrid hazel-nut cultivar Dawei were applied, which was based on the annual fertilization rate determined by leaf nu-trition diagnosis. There were four fertilization modes, including the traditional fertilization mode (CK), the fertigation mode with total fertilization amount (T1), the fertigation mode with half fertilization amount (T2) and the traditional fertilization mode combined with drip irrigation (T3). According to leaf nutrition diagnosis, the fertilization amounts in different fertilization modes were as follows:(1) tradi-tional fertilization treatment, according to the local farmers’routine procedure, the topdressing period was divided into two stages, i. e., current shoot rapid growth stage and kernel filling stage. During curre-mt shoot rapid growth stage, the fertilization amount was set as available nitrogen 90 g · plant-1, avail-able phosphorus 83 g · plant-1 and available potassium 44 g · plant-1, respectively. During kernel filling stage, the fertilization amount was set as available nitrogen 90 g · plant-1, available phosphorus 57 g · plant-1 and available potassium 83 g · plant-1, respectively. (2) With T1 fertilization treatment, the topdressing period was divided into four stages, i.e., current shoot elongation stage, current shoot rapid growth stage, kernel filling stage and postharvest stage. During current shoot elongation stage, the fertilization amount was set as available nitrogen 45 g · plant-1, available phosphorus 28 g · plant-1 and available po-tassium 16 g · plant-1, respectively. During current shoot rapid growth period, the fertilization amount was set as available nitrogen 45 g · plant-1, available phosphorus 56 g · plant-1 and available potassium 28 g · plant-1, respectively. During kernel filling stage, the fertilization amount was set as available nitro-gen 54 g · plant-1, available phosphorus 42 g · plant-1 and available potassium 42 g · plant-1, respectively. During postharvest stage, the fertilization amount was set as available nitrogen 36 g · plant-1, available phosphorus 15 g · plant-1 and available potassium 41 g · plant-1, respectively. (3) With T2 fertilization treatment, the topdressing stage was the same as T1 treatment. The only difference between T1 and T2 was the fertilization amount applied, which of T2 treatment was reduced to half of T1 amount in every topdressing stage. (4) With T3 fertilization treatment, the topdressing period was the same as CK treat-ment. The only difference between T3 and CK was different type of irrigation applied. T3 fertilization treatment was irrigated by drip irrigation at four topdressing stages of T1.【Results】The application of drip irrigation and fertilization could improve leaf photosynthetic characteristics, yield, growth and leaf nutrition level in the hybrid hazelnut. (1) The effect of 4 fertilization modes on photosynthetic character-istics was as follows:compared with CK mode, the leaf Pn, Gs, Tr and Ci of hybrid hazelnut with T1 or T2 modes were all significantly superior to CK (p＜0.01), but there was no significant difference (p＜0.05) between T1 and T2 modes or between T3 and CK modes. Except leaf Ci, the other photosynthetic characteristics with T1 or T2 modes were also significantly superior to those with T3 mode. (2) The ef-fect of 4 fertilization modes on leaf nutrition level was T2＞T1＞T3＞CK. (3) The effect of 4 fertiliza-tion modes on yield was T1＞T2＞T3＞CK. Compared with CK mode, the average fresh nut weight per plant with T1, T2 or T3 modes was significantly superior to CK, and that of T1 or T2 mode was sig-nificantly superior to T3 mode but there was no significant difference between T1 and T2 modes. The effect of 4 fertilization modes on PFP was T2＞T1＞T3＞CK. Compared with CK mode, the PFP of T2, T1 and T3 modes increased by 372.3%, 143.5%and 98.2%, respectively. (4) The effect of 4 fertil-ization modes on nut fresh weight or nut dry weight was T1＞T2＞T3＞CK. Compared with CK mode, the nut fresh weight or nut dry weight with T1 mode was significantly superior to CK, but there was no significant difference among T1, T2 and T3 modes, or among T2, T3 and CK modes. Compared to CK mode, the cross diameter of nut with T1, T2 and T3 modes were all significantly superior to CK, but there was no significant difference among T1, T2 and T3 modes. The longitudinal diameter of nut with T1 and T2 modes were all significant superior to CK, but there was no significant difference between T1 and T2 modes or T3 and CK modes. (5) The effect of 4 fertilization modes on plant growth indexes were as follows:the ratio of branch basal diameter/length (×100) with T1 mode was significantly supe-rior to T2, T3 or CK mode. As to the difference-value of crown diameter or the difference-value of trunk girth among 4 fertilization modes, there was no significant difference. The fertigation could in-crease the percentage of 40-60 cm annual branches, which were the best fruiting branches with 4 fertil-ization modes.【Conclusion】According to the leaf photosynthetic characteristics, yield, nut weight, growth indexes and leaf nutrition level of the hybrid hazelnut, four fertilization modes were evaluated by principal component analysis (PCA). The results indicated that T2 mode was the best fertilization model for hybrid hazelnut cultivar Dawei.
万方数据
维普
