Horticulture: Training and Pruning of Plants

Training and Pruning

• Training of plants in the young stage is essential to build a strong framework and avoid weak crotches.
• Fruiting trees are pruned to check overcrowding in the orchard.
• Plants are trained as low-headed trees to facilitate multiple hand pickings.
• Guava is generally trained to a modified leader system.
• Pruning is usually recommended after harvesting or in spring.
• Summer pruning is generally avoided as plants get damaged due to sunburn.

Bending

• Bending is a common feature in guava trees, where branches growing upright and tall don't bear at all.
• Straight-growing branches may be bent and tied on pegs driven on the ground to activate dormant buds and induce heavy flowering and fruiting.
• This method is successful especially in varieties that grow erect and bear little fruit.

Intercultural Operations

• Weeds are usually removed by shallow cultivation.
• Green manuring is usually done during the rainy season.
• Pre-emergence use of diuron, oryzalin, simazine, or atrazine has been found to be effective in controlling weeds in guava orchards.

Mulching

• Dry leaves or straw are used as mulching material.
• Mulching can also be done with black polyethylene sheet or organic materials.
• Mulching the soil at least twice a year helps in conserving moisture and improving the fruit quality.

Intercropping

• Leguminous crops or vegetables can be grown as intercrops during the first three years of planting, provided irrigation facility is available.

Growth Regulators

• The winter crop is much superior in quality compared to the monsoon crop.
• Farmers often reduce the monsoon crop by deblossoming to get a higher price.
• Growth regulators like maleic hydrazide, NAA, NAD, and 2,4D have been found to be effective in thinning of flowers and manipulating the cropping season.

Manurial and Fertilizers

• Recommended manurial and fertilizers doses are:
  • FYM: 20, 10, 15, 20, 25, 30, 40 kg/plant for I, II, III, IV, V, VI, and VII years onwards respectively.
  • Nutrients: Nitrogen (100, 200, 300, 400, 450, 500), Phosphorus (50, 100, 150, 200, 200, 250), Potash (25, 50, 75, 200, 200, 250), ZNSO4 (25, 25, 50, 50, 100, 150), FeSO4 (25, 25, 50, 50, 100, 150), and MnSO4 (25, 25, 50, 50, 100, 150) for I, II, III, IV, V, VI, and VII years onwards respectively.

Interculture

• Important inter-culture operations for soil aeration and health include ploughing, spading of basins, and weed control.
• Chemical control of weeds with pre-emergence weedicides like diuron, simazine, glyphosate, and paraquat may also be adopted.

Intercrops

• Leguminous crops like soybean, gram, groundnut, cow peas, French bean, and peas can be grown in citrus orchards.
• Intercropping is advisable during the initial three-four years after planting.

Training and Pruning

• To allow the growth of a strong trunk, initially shoots up to 40-50 cm from the ground level should be removed.
• The centre of the plant should remain open, and branches should be well distributed to all sides.
• Cross twigs and water suckers should be removed early.
• The bearing trees require little or no pruning.
• All diseased, injured, and drooping branches and dead wood should be removed periodically.

Harvesting

• There are two main crops in mandarins and sweet oranges.
• K2O/tree/year is applied, and the dose is regulated on the basis of the age of the tree and the status of nutrients in the soil, especially P and K.

Micronutrients

• In case of Zn and Fe deficiency, organic manures, ZnSO4, and FeSO4 (0.5%) are applied.

Irrigation

• Irrigation is provided at an interval of 30 days in winter and 15 days in summer.
• Drip Irrigation system has been found to be beneficial in saving 40% water with 70-75% higher income.

Intercultural Operations

• Application of 2 kg bromacil and 2 kg diuron/ha as pre-emergence spray is effective in controlling weeds for a period of 10-12 months.

Inter-cropping

• Inter-cropping with banana, papaya, pineapple, and cocoa; French bean, peas, tomato, brinjal, cabbage, cauliflower, and cucurbits is recommended depending on the climate and irrigation facilities available.

Growth Regulators

• Fruit drop is a very serious problem in sapota.
• Spraying with GA3 @ 50-100 ppm at the time of flowering is quite effective for getting better fruit set and also preventing fruit drop.

Harvesting and Yield

• Sapota takes about 7-10 1/2 months from anthesis to maturity of fruits depending on the variety and climate.
• Fruits follow a double sigmoid pattern of growth.
• Properly developed fruits have high TSS and sugar, and reduced acidity, astringency, latex, and vitamin C.
• Maturity is decided on the basis of ease with which brown scruff gets off the fruit surface and development of yellowish tinge intermixed with corky brown color on the surface of the fruit.