The symptoms include large dry lesions at the blossom end of the avocado fruit, which are dark brown, leathery and hard.
Coul you provide information regarding environmental conditions, variety, chemical sprays applied during bloom and early frut set, as well as on intensity of the problem at the orchard and tree level?
- Are these as individual symptoms or generally occurred in whole the orchard.
- It seems to be done in late growth stages of the fruit.
It could be as calcium deficient symptoms or sun burning if this part of the fruit is in the sun light directly, or microbial disorders.
Could you please let us know if these symptoms are visible in fruit still on the tree and if so, where in the tree canopy these fruits are located (e.g. on lower branches, etc). Thank you :)
Thanks to all for yours interested, The plants were grown in Jericho, Jordan Valley, very hot condition and dry. The soil was rich with calcium carbonate. The symptoms were uniform on all trees and on the same tree. The symptoms were developed and larged with fruits. The plants didnot sprayed with any insecticdes or fungicides or acaricides. In addition, the trees were shaded witrh black 60% mesh.
Dear Mohammed. Thank you for the information. My initial thoughts were that this might be sunburn, but shading trees with 60% black shade mesh makes this very unlikely. From the photographs provided, which show the surface of affected fruits, my best guess would be Phytophthora. Although Phytophthora rot affects roots as we all know, it also infects fruits, although usually those located within say a metre of the ground, on avocado trees under sprinkler irrigation, growing on bare soils (not covered by a mulch of fallen leaves or a wood-chip mulch added to the soil surface) I have seen fruits that look very similar to those in your photograph, and had the cause confirmed as Phytophthora. I cannot say for certain, but I hope you might find some use in my comments.
perhaps physiological disorder because high temperature conditions
Dear Mohammed. You can confirm whether it is phytopthora through incubation. It only grow on host and not on PDA or any other artificial nutrient rich media.
Dear Mohammed: under hot and dry conditions the transpiration is reduced and you will have Ca deficiency in fruits. I recommend you make nutritonal analysis of your fruits so you can check what happened with your fruits.
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