Abstract:

The aims are to clarify the accumulation and distribution dynamics of dry matter (DW) and nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) of wax gourd, and provide a scientific basis for precise fertilization of wax gourd. The large black wax gourd ‘Tiezhu No. 2’ was used as the material in this study. Four plant sites, including leaf, petiole, stem and fruit, were collected at seedling stage, flowering stage, fruit setting stage, fruit expanding stage and fruit mature stage, respectively. The DW and N, P, K, Ca and Mg contents were measured. The accumulation of DW in the shoot of wax gourd showed an “S” shaped curve. The total accumulation of DW in the shoot was 4903 kg/hm², the DW accumulation in the fruit was 3438 kg/hm² and the harvest index was 0.7 in the whole growth period. The total nutrient absorption exhibited a trend of K>N>Ca>P>Mg, and the amount of N, P, K, Ca and Mg was 293 kg/hm², 104 kg/hm², 103 kg/hm², 24 kg/hm² and 20 kg/hm², respectively. The accumulation of N, K, Ca and Mg reached the peak at the fruit setting stage, accounting for 39.9%, 32.7%, 30.1% and 40.9% of their total absorbed amounts in the whole growth period, respectively. The P absorption was mainly at the mature stage, accounting for 47.6% of its total absorption in the whole growth period. The total amount and proportion of nutrients demanded in each growth stage of wax gourd are different, so the fertilization strategy should be adjusted in time according to the target of cultivation. Fruit setting stage is particularly important for high yield and fertilizer efficiency of wax gourd, and great attention should be paid to the supplement of Ca and Mg after fruit setting.

Key words: black wax gourd, dry matter, nutrient absorption, nutrient distribution, dynamics