On No. 2, we grow guavas in the Philippines. Fruit fly and tea mosquito are the major pests. For the fruitfly, we use methyl eugenol attractant and wrap the fruits with newspaper and plastic bags. It is increasingly difficult to find cellophanes that last long enough now, so we are experimenting using banana wrap. Wrapping is also necessary to prevent sunburn. We are still working on an effective control for tea mosquito, as they even attack the buds. They are seasonal. Stem borer also attack - everything above dies but below is OK. When we see it we kill the borer, but it is a minor pest so we don’t do any other control.
Anthracnose is also a problem, for some reason worse for us in the dry season than the rains. Applying IMO to the ground and spraying it is helping control it.
At 5-7 years, the trees will often die (dieback). I have read that using cover crops reduces this and also grafting on to native rootstock. We are starting to grow natives for rootstock now.
Apart from the first year, we don’t do any weeding, just cutting. We did, but there was no benefit and the roots are very shallow, so easily damaged. We’re planting perenial peanut underneath now.
No.3. We buy UV resistant tarpaulin, which we get in a 3m width, so have a long pond. When the rains return we remove the tarpaulin to prolong it’s life. An 8m3 pond cost less than $100. We only need small ponds as we are able to fill overnight for use in the day. We installed a Philippine made drip irrigation system on over 800 guavas for a total cost of around $1.20 per tree. This also we remove when not in use. For some trees we use a tanker to water them. If you require any more details about any of these let me know.
Also if anyone has any tips on pest and disease control I would be delighted to hear.