A Detailed Guide to Newhall Navel Orange Planting Techniques and Management Key Points
Newhall navel orange (Citrus sinensis 'Newhall') originated in the United States and was introduced to China in 1978. Newhall navel oranges have always had a fairly good market in China. The following mainly explains what the planting techniques for Newhall navel oranges are.
1. Do a good job of soil improvement and planting
Before planting, dig planting trenches and bury weeds, rice straw, cake fertilizer and other materials to improve the soil. The trench should be 0.7 m deep and 1.0-1.3 m wide. First place a layer of rice straw at the bottom of the trench. If it is acidic red-yellow soil, evenly scatter some lime on the rice straw, cover with a layer of soil, then place weeds and rice straw, scatter some lime, and cover with another layer of soil. After leveling, place rice straw, weeds, pig and cattle manure, tung oil cake, etc., mix with soil and backfill, so that the trench surface is about 30 cm above ground level. Finally, cover the planting trench surface with a layer of decomposed farmyard manure and let the backfilled area settle naturally. When improving the soil, use 20-25 kg of rice straw and weeds, 1.5-2 kg of lime, and 10 kg of cake fertilizer and pig and cattle manure per plant. Plant after the beginning of spring (in areas with frost damage). After planting, water once a day for 1-7 days, and begin watering with decomposed dilute liquid fertilizer after 10-15 days.
2. Water management
Irrigate in a timely manner during drought and drain promptly during the rainy season. Irrigation can be done by sprinkler irrigation, drip irrigation, or manual watering. The orchard should not be irrigated during the 1 month before fruit harvest, and must be irrigated once within 1 week after fruit harvest.
3. Flower and fruit retention
Based on the nutritional status of the navel orange tree, appropriately use nutritional growth regulators to increase fruit set rate and yield. Spray 0.01% brassinosteroid at 2000-2500 times dilution 40-50 mg/L + 0.2% monopotassium phosphate, once every 15 d, for 2 consecutive sprays, generally when 2/3 to 3/4 of the flowers have fallen and before the second physiological fruit drop. The use of microelement fertilizers and nutrient elements for flower and fruit retention is encouraged, while high-concentration and repeated use of growth regulators for flower and fruit retention is prohibited.