For commercial purposes, the land should be thoroughly prepared. Plow the area 2-3 times followed by harrowing until the desired tilth of the soil is attained. It should be done before the start of the rainy season. For backyard or reforestation purposes, just underbrush the area and if possible collect all cut grasses, shrubs, and other rubbish-es and burn them. The soil should be cultivated properly in order that the seeds may be sown with the required depth or that holes may be dug deep enough to bury the ball of seedlings.
Rows of cashew trees should be properly laid out with the proper distancing by placing markers at the desired distance between hills in a row before digging the holes.
Distance of Planting
Distance of planting varies according to the purpose for which the trees are planted. For reforestation, 3m x 3m is recommended to encourage early shading and to aid in smothering weeds.
For commercial plantings in the Philippines use 6m x 6m which is too close compared to the practice in other countries.
Triangular planting was found to be most productive layout and should be tried. This method, how-ever, is rather difficult for farmers to follow.
High density planting gives more kernel per hectare up to age 7 years. Low density planting gives less per hectare but more per tree.
- A. Triangular (12m x 12m x 12m) = 79 plants/ha. An alternative and easier method is the quincunx arrangement and should also be tried.
- B. Quincunx (15m x 15m) = 76 plants/ha
- C. Square – The simplest recommended planting distances are 9m x 9m at the less fertile lower slopes and 10m x 10m at the more fertile lower slopes.
Lining, Stacking and Digging of Holes – Rows of cashew should be properly laid out by placing markers between rows and between hills in a row. The holes should be dug a month before the planting of seedlings. The holes should have a dimension 20 cm x 20 cm.
Planting Time – In places with distinct dry and wet seasons, planting is best done at the start of the rainy season.
There are two methods of establishing cashew that may be employed. These are direct seeding and transplanting of seedlings or sexually propagated materials.
In direct seedlings, 2 to 3 seeds are planted 5-10 cm deep with the stalk end facing upward and in a slanting position. This prevents emerging cotyledons at the soil surface from the ravages of field rats, ants, snails and birds.
Seeds are planted 30 cm apart in a triangular position when 3 seeds are used. The seeds will germinate 1-2 weeks after sowing provided that the soil has sufficient moisture.
Thinning should be done leaving only the most vigorous plant to develop 1-2 months from germination. Thinning is preferably done during the start of the rainy season.
When transplanting seedlings or sexually propagated materials, remove carefully the polyethylene plastic before setting the seedlings in the holes. Fill the holes with surface soil first and firm the soil at the base of the seedling carefully allowing the roots to remain in as natural as possible.
Weeding and Cultivation
The plants should be cultivated and free from weeds at a distance of 1 meter around the trunk. The orchard should be weeded as often as necessary. Cut grasses should be left in the area between the hills to dry and to used later for mulching. Mulching helps conserve moisture around the plant during the summer months, keep down the weeds and increase the amount of humus in the soil when decays.
Irrigation is needed during the first dry season. Unlike in the subsequent years, when the root system has already been established and have reached the layer with sufficient moisture. For better yield, it is advisable to irrigate the field regularly especially during summer.
Intercropping and Covercropping
A considerable part of the land is available for intercropping during the early years after the establishment of the cashew orchard.
To provide sufficient protection from the heavy growth of weeds and grass, the spaces between rows may be used for planting cash crops. This would enable the grower to earn additional income.
Annual crops can be interplanted between rows of cashew provided they are not closer than 2 meter from the cashew tree.
When the growing of intercrops is no longer feasible, the field should be planted to leguminous covercrops. The planting of covercrops will prevent further soil erosion, conserve moisture, and add organic matter to the soil. The area within 1 to 1-1/2 meters from the trunk should be kept free from weeds and covercrops should not be allowed to cling to the tree.
Little pruning is practiced in ca-shew. However, it may be necessary to prune regularly to get the desirable shape of the tree and to facilitate cultural operations.
It is also necessary to remove the diseased and infected branches and unnecessary water sprouts.
Cut wounds should be properly treated with chemicals (coaltar) to facilitate healing and avoid infections.
It is advisable to apply fertilizers especially when soil analysis dictates specific soil nutrient deficiencies. The general recommendations are the following:
- Seed-lings – At planting time apply complete fertilizer (14-14-14) before the seedlings are set in the holes at the rate of 200-300 gm/plant.
- Young Trees – Apply complete fertilizer at the rate of 300-500 gm/tree plus Urea (45-0-0) at the Young Trees – Apply complete fertilizer at the rate of 300-500 gm/tree plus Urea (45-0-0) at the rate of 200-300 gm/tree.
- Bearing Trees – Apply complete fertilizer (14-14-14) at the rate of 1.5 to 3.0 kg/tree
Recommended rate of fertilizer application is applied two times a year. One half of the total requirement per tree should be applied at the start of the rainy season and the remaining half should be applied toward the end of the rainy season.
On established trees, fertilizer should be dug with a depth of 1-10 cm. The fertilizer is then distributed equally. Cover the holes/canal properly with soil to prevent the fertilizer from evaporating or from being washed out by heavy rains.