Flushing, Flowering and Fruiting in Cashew

Flushing in Cashew

(a)  Only  flushing  is  observed  while  there  is  no  yield.  What  is  the  reason  for  this?

(b) Some trees flush profusely but won't flower. Why?

This type of variation is observed in the plantations which are established with seedling progenies or the plants may be suffering due to poor soil fertility and lack of moisture in the soil.  This problem  will  not  be  seen  in  the plantations established  with  grafts  following recommended package of practices.

Flowering in Cashew

(a) One year old cashew grafts have flowered. Whether the flowers are to be removed. If so why? If flowers are not removed whether the plant dies?

Upto two years after planting, flowers should be removed to allow the canopy to develop and to put forth good vegetative growth. The plant does not die if the flowers are removed.

(a)  Some       trees       don't       yield       despite       profuse        flowering.       Why?

(b) Though there is profuse flowering there is no yield. Why?

In a plantation raised with seedlings, these types of trees are very common. As they produce mostly the male flowers (99%), we won't get any yield from them. Such plants have to be removed or top worked with a high yielding variety. Hence, plantation should be established with grafts of high yielding varieties which have high sex ratio (more number of bisexual flowers) to overcome this problem.

(a) Why all the cashew plants don't flower at a time?

Cashew is a highly cross pollinated crop and the seeds are heterogegenous. Hence in a plantation which is established with seedlings, all the plants do not flower at a time. If the orchard is established with grafts of a particular variety all the plants will come to flower at a time.

(a) Numbers of male flowers are more than that of bisexual flowers, why?

In each cashew flower panicle there will be 200-800 flowers, of which 0.5 – 25.0 per cent will be bisexual flowers depending upon the variety. This is a genetically controlled character. All the high yielding varieties of cashew produce more number of bisexual flowers (i.e. they have high sex ratio).

(a)  Whether morning dew during flowering causes low yield?

If the flower opening in cashew coincides with morning dew/fog, then the moisture accumulates on the dried up male flowers which are in plenty and cloudy weather continuously for 2-3 days during this period will result in drying up of flowers/entire flower panicle. During cloudy weather the population of tea mosquito and flower thrips population may also increase, resulting in crop loss.This results in poor yield.

(a) What is the reason for less flowering during some years?

Generally cashew plants require about 25-30 days of dry spell before producing new flushes and flower panicles. If the rainfall is received even during Nov-Dec, months less flowers panicles are produced, particularly in the early flowering types.

(a) One to two year old grafts are turning red and dying after removing flowers. What is the reason?

The plants will not die if flower panicles are removed from one to two year old cashew grafts. The plants may be dying due to lack of moisture in the soil. Hence, pot watering should be done during summer months, particularly during the first year of planting.