Abstract:

The paper aims to explore the effects of different strains of guava as grafting rootstocks on the growth, fruit yield and quality of ‘Hongxiang No.1’ guava, and to screen out suitable strains for grafting rootstocks of ‘Hongxiang No.1’ guava. Through field comparative experiments, in the autumn of 2019, the seedlings of ‘Pocket’, ‘Guokeng’, ‘Rainbow’, and ‘Hongxiang No.1’ were used as rootstocks, and the superior plant of ‘Hongxiang No.1’ was used as scions. Grafted seedlings were cultivated and planted in the spring of 2020. From 2021 to 2023, the nutritional growth (stem diameter, plant height, and crown width), fruit yield (single fruit quality and single plant yield), fruit appearance quality (longitudinal diameter, transverse diameter, and fruit type index), and physiological indicators (soluble solids, soluble sugars, reducing sugars, vitamin C, and titratable acid) of ‘Hongxiang No.1’ were continuously observed. In terms of nutritional growth, ‘Rainbow’ rootstock had the largest stem diameter in the early stage and was significantly larger than other treatments. As the growth period extended, there was no significant difference in stem diameter indicators among ‘Rainbow’ rootstock, ‘Guokeng’ rootstock, and ‘Hongxiang No.1’ rootstock. The height of ‘Rainbow’ rootstock was significantly higher than other treatments, while the height of ‘Pocket’ rootstock was the lowest. The crown width of ‘Rainbow’ rootstock was significantly higher than other treatments, while the crown width of ‘Pocket’ rootstock was the lowest and significantly lower than other treatments. Taking into account four batches of fruits over a period of three years, the ‘Rainbow’ rootstock had the highest single fruit quality and single plant yield, both significantly higher than those of other treatments. The ‘Pocket’ rootstock had the lowest single fruit quality and single plant yield. The four rootstocks had a certain impact on the appearance quality and physiological indicators of ‘Hongxiang No.1’ guava. Among the four batches of fruits in three years, ‘Rainbow’ rootstock had the highest vertical and horizontal diameter and fruit shape index, while ‘Pocket’ rootstock had the lowest vertical diameter. There was no significant difference in appearance quality indicators between ‘Guokeng’ rootstock and ‘Hongxiang No.1’ rootstock. The comprehensive performance of physiological indicators such as soluble solids, soluble sugars, reducing sugars, vitamin C, and titratable acid content in ‘Rainbow’ rootstock fruits was better than other treatments. The combination of ‘Rainbow’/‘Hongxiang No.1’ rootstock and panicle showed better nutritional growth, fruit yield, and quality than other treatments. Therefore, ‘Rainbow’ seedling was suitable as grafting rootstocks for ‘Hongxiang No.1’ guava.

Key words: guava, grafting, rootstock, combination of rootstock and scion, growth, yield, fruit quality