How to choose the right rootstock when raising grafted ponkan seedlings
Selection of rootstock for grafted ponkan seedling propagation
1. Principles of rootstock selection
First, suitable ecological conditions. That is, the selected rootstock must suit the ecological conditions of the ponkan growing area. Second, the compatibility between rootstock and scion. To ensure that grafted ponkan seedlings grow and develop normally, bear fruit early, yield abundantly and consistently, and produce high quality, the rootstock-scion combination must be highly compatible, so as to prevent compatibility from affecting yield, especially premature decline. Third, strong resistance. The selected rootstock variety should have such good traits as resistance to pests and diseases, cold, drought and salinity-alkalinity. Fourth, good nursery performance. That is, the rootstock seeds are easy to collect, are produced in large quantities, are convenient to propagate, and give high rates of seedling emergence, seedling survival and quality seedlings. Fifth, a high degree of polyembryony. Monoembryonic varieties and low-seeded varieties are generally not suitable as rootstocks. The rootstock for ponkan should be a polyembryonic variety.
2. Suitable rootstocks for ponkan
For ponkan, trifoliate orange, Fuju mandarin, sour mandarin, red tangerine, Fuju and ponkan itself can be used.
Trifoliate orange: Ponkan on trifoliate orange rootstock bears fruit early and yields abundantly; its canopy grows fast before fruiting, which lays a good foundation for quickly entering the high-yield period after coming into production. After coming into production, the canopy grows slowly, which provides favorable conditions for dwarf dense planting, increasing yield per unit area and convenient management. The drawbacks are that fruit quality is slightly inferior, the fruit stores less well than that on red tangerine rootstock, and the tree vigor tends to decline after a heavy crop, so management must be strengthened to improve tree vigor.
Fuju: The rootstock-scion compatibility is good, the graft union is smooth with no obvious line of demarcation, and the plant grows fast. Early yield is slightly lower than that on red tangerine rootstock, but the fruit's juice yield and flavor are richer than those of ponkan on trifoliate orange rootstock, and the melting quality in the mouth is also better than that on trifoliate orange; the fruit rind is smooth and its storage ability is strong. The drawback is that early-stage yield is on the low side.
Sour mandarin: The rootstock and scion are compatible, growth is vigorous, the canopy is tall, the lifespan is relatively long, and fruit quality is good; the drawbacks are late fruiting and late heavy bearing. It is the main rootstock for ponkan in Guangdong and Guangxi.
Red-skin mountain mandarin: Similar to sour mandarin, it is a rootstock used for ponkan in Guangdong and Guangxi.
Ponkan: Fruiting is later than that of ponkan on trifoliate orange rootstock, and heavy bearing is also somewhat later, but late-stage yield is high and fruit quality is good. Fuju and ponkan are the traditional rootstocks in the ponkan production areas of Fujian.
First, suitable ecological conditions. That is, the selected rootstock must suit the ecological conditions of the ponkan growing area. Second, the compatibility between rootstock and scion. To ensure that grafted ponkan seedlings grow and develop normally, bear fruit early, yield abundantly and consistently, and produce high quality, the rootstock-scion combination must be highly compatible, so as to prevent compatibility from affecting yield, especially premature decline. Third, strong resistance. The selected rootstock variety should have such good traits as resistance to pests and diseases, cold, drought and salinity-alkalinity. Fourth, good nursery performance. That is, the rootstock seeds are easy to collect, are produced in large quantities, are convenient to propagate, and give high rates of seedling emergence, seedling survival and quality seedlings. Fifth, a high degree of polyembryony. Monoembryonic varieties and low-seeded varieties are generally not suitable as rootstocks. The rootstock for ponkan should be a polyembryonic variety.
2. Suitable rootstocks for ponkan
For ponkan, trifoliate orange, Fuju mandarin, sour mandarin, red tangerine, Fuju and ponkan itself can be used.
Trifoliate orange: Ponkan on trifoliate orange rootstock bears fruit early and yields abundantly; its canopy grows fast before fruiting, which lays a good foundation for quickly entering the high-yield period after coming into production. After coming into production, the canopy grows slowly, which provides favorable conditions for dwarf dense planting, increasing yield per unit area and convenient management. The drawbacks are that fruit quality is slightly inferior, the fruit stores less well than that on red tangerine rootstock, and the tree vigor tends to decline after a heavy crop, so management must be strengthened to improve tree vigor.
Fuju: The rootstock-scion compatibility is good, the graft union is smooth with no obvious line of demarcation, and the plant grows fast. Early yield is slightly lower than that on red tangerine rootstock, but the fruit's juice yield and flavor are richer than those of ponkan on trifoliate orange rootstock, and the melting quality in the mouth is also better than that on trifoliate orange; the fruit rind is smooth and its storage ability is strong. The drawback is that early-stage yield is on the low side.
Sour mandarin: The rootstock and scion are compatible, growth is vigorous, the canopy is tall, the lifespan is relatively long, and fruit quality is good; the drawbacks are late fruiting and late heavy bearing. It is the main rootstock for ponkan in Guangdong and Guangxi.
Red-skin mountain mandarin: Similar to sour mandarin, it is a rootstock used for ponkan in Guangdong and Guangxi.
Ponkan: Fruiting is later than that of ponkan on trifoliate orange rootstock, and heavy bearing is also somewhat later, but late-stage yield is high and fruit quality is good. Fuju and ponkan are the traditional rootstocks in the ponkan production areas of Fujian.