Hello all. I'm in the process of installing irrigation in the citrus groves in my spare time, but with the heat, I'm afraid I might not be installing it fast enough. Does anyone know if I cut the trees back, will that cut down on the amount of water needed? The trees are established (20+ years old) and are doing well despite not being watered, but I'd like to keep them alive until I get a chance to top work and convert them over to another cultivar.

Thanks,
Phillip

Transpiration is a major use of water by plants, so by cutting back on the leaves available for transpiration it would have to reduce water use. It might help to coat the cut ends of limbs with wax or parafilm to make sure it is not loosing water thru the cut end of the limb.

Trees evaporate water through the openings in their leaves in the process of transpiration, and they tend to transpire more with increased temperatures, and sunlight intensity. Many factors influence transpiration rates, including leaf shape, leaf size, stomata size, and waxiness of the leaf surface. Trees transpire vast quantities of water - only one percent of all water a plant absorbs is used in photosynthesis; the other 99 percent is lost through the leaves. Therefore, by reducing the volume of the leaf surface, you also GREATLY reduce the volume of water required by the tree. I would not apply anything at all to the cut surfaces. I would leave them alone and let them seal themselves naturally. By using the search function you will be able to find several posting by Dr. Manners where he advises that it is best not to apply anything to a cut end. Citrus are very capable of withstanding a hard pruning, with very little, or no long term damage. Good luck. - Millet (1,283-)

Perfect, thanks gentlemen. I had suspected as much, but wanted to get an expert opinion. Now I just need to work on getting a chipper/shredder to handle the cut branches. It may be questionable whether it would take more time to cut the trees or install irrigation. Maybe a combination of both until I can do something with the trees. My well pump costs are killing me as it is.

Phillip

Philip, why do you have a high cost to operate your well? I have two wells........ 1.) a residential well at 240 feet deep which supplies water to the house and two barns. 2). a larger volume irrigation well at 980 feet deep for crops. The cost of running them does not amount to much of anything. California must have much higher electric charges. - Millet (1,283-)

Depending how much you cut them back, you might want to whitewash the newly exposed trunk and limbs, especially if you are already into hot weather over there. In fact if you suddenly expose major areas to direct sun after pruning, you could do some damage. Also if you plan to topwork in the future, it may be wise to do any pruning higher up than your intended grafting height. This will give you some leeway when cutting the limbs to graft later on.
You may like to look at
http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0003/99273/managing-citrus-orchards-with-less-water.pdf
Which is a NSW primefacts factsheet on drought measures.

One other point to consider, once you cut the limbs it will be at least a month before the bark will slip again.

There is a good photo essay about various drought responses in citrus orchards at Citrus Drought Workshop
Additional_tree_management_strategies_v7.pdf(application/pdfObject)


http://www.pir.sa.gov.au/__data/assets/pdf_file/0020/55118/Addtional_tree_management_strategies_v7.pdf