Dear Dr. Parmeshwar Shirgureji,

Please follow  the following links and the attachments for the answer to your query.

http://world-food.net/the-effects-of-mechanical-pruning-on-fruit-yield-and-quality-in-star-ruby-grapefruit/

http://hortsci.ashspublications.org/content/35/1/30.full.pdf

Regards,

Dr. Arvind Singh

Dear Parameshwar,

Increasing the high-quality yield of a cultivated fruit species is an important method for improving its ability to compete in world markets. A high fruit yield and an increase in the proportion of marketable fruit will aid in obtaining the market objectives for the species. To this end, pruning is a very important horticultural practice. Mechanical pruning has numerous advantages over classical pruning, such as enabling control over the tree size and providing mechanization in large and dense orchards that make hand pruning applications difficult and expensive. Mechanical pruning is used widely in developed countries for many horticultural crops including citrus. Experiments in non-selective mechanical pruning began in the 50s in USA, showing that mechanical pruning followed up by hand pruning can reduce costs by 30-50% without affecting yield and fruit quality , but results are highly variable because they depend on several factors such as species, varieties, pruning time, tree size, tree age, and crew experience among others.

Productivity of mechanical pruning is  calculated according to:

P=1000 .N/A.L{L/1000.V +G/60}

where A and L are between-row width and row length (m); N is the number of passes that the machine performed per row; V is the tractor advance speed (km h–1) and G is the time used in manoeuvres to change row (min).

Mechanical pruning reduced the amount of time needed for follow-up hand pruning by around 13%. Hand pruning required 101.1 h ha–1 versus 88.0 h ha–1 for follow-up hand pruning.

Followings are advantages-

1. Pruning is depressing to vine function and decreases vine capacity.

2. Crop is also depressing to vine capacity for following year(s).

3. Capacity of a vine is related to number of shoots and amount of crop present.

4. Shoot vigor is inverse to the number of shoots and to crop load.

5. Bud fruitfulness is inverse to shoot number.

6. Large canes or arms can produce more than small ones and should carry more fruit buds.

7. A vine can nourish and ripen only a certain amount of fruit.

8. Capacity of a vine is limited by its previous history and environment.

Regards,

Prem Baboo

Though , citrus is claimed to be less responsive to pruning , but actually it responds well to pruning . Removal of infected drywood lengthens the productive life span of trees and rejuvenate the fruit bearing area. So , undoubtedly , there has been better quality fruits with pruning practices.

Dear Dr Prem Baboo, i am thankful to you for your valuable input on mechanical pruning of fruit trees. This information can be used for calculating the productivity. The uniformity of the fruits is well attained by this mechanization besides the yield and internal fruit quality. The precision citriculture is possible with this type of practice.  Thanks.

Dear Dr. Shigure

There is good information on citrus mechanical pruning in attached files, which I hope will be useful to you.