4 Threats to Almond Orchards’ Productivity
Nut-bearing trees, such as almond trees, are some of the hardiest crops in existence, usually able to grow and flourish even in tough climate and soil conditions. However, just because they’re hardy doesn’t mean that they can be neglected the moment they’re planted. They need the same care and attention as other crops do due to the fact that they’re just as vulnerable to many of the usual threats that can have a detrimental effect on the growth and health of plants. These include pests, diseases, irrigation issues, and nutrient deficiencies. As such, orchard operators and farmers should take the necessary measures in order to mitigate such threats well in advance.
One example of such measures is spectral imagery for crop health management. This involves having a professional imaging team fly an aircraft over an orchard to capture high-resolution images at specific wavelengths using a spectral camera system. Specialized image processing techniques as well as biological and mathematical modeling are then carried out to correlate data to the physical condition of the plants, revealing information regarding important plant health factors like water stress, vegetative vigor, chlorophyll content, disease activity, and many more. The health problems can then be addressed directly, eliminating the need for costly guesswork and wasteful trial-and-error.
Technologies such as aerial spectral imagery can be used with a variety of other tools such as ground-based sensors, on-site weather stations, and automation technologies to minimize the almond trees’ vulnerability to common threats. Some of these threats are discussed below.
Many fruit and nut trees are different from other trees because they need to be pruned every now and then to ensure that they yield high-quality produce. This is because too much vegetative vigor and canopy cover can prevent sunlight penetration and air movement within the inner sections of the trees. By ensuring that sunlight and air are available to all parts of your almond trees, they will be able to produce more and better-quality almonds. Moreover, proper pruning can also help prevent the spread of diseases due to overcrowding while also improving the structure of the trees so that they can better sustain their future crop load.
Pruning issues is one area in which imaging technologies such as normalized difference vegetation index imagery can help.
Insects and other pests
Just like any other crops, the almond tree is vulnerable to many insects and pests that can have a detrimental effect on its growth and health. Allowing them to infest your almond tree orchard can not only affect the quantity of produce you’ll get come harvest time, they could also kill off your trees completely and even spread to your other crops. As such, you need to ensure that your orchard is protected against them.
The most common and damaging examples of these pests include the following:
- Aphids and scales. Aphids and scales suck the sap right out of your almond trees’ leaves, causing them to wilt and drop quickly. This can hamper your trees’ growth, health, and overall almond production. An aphid/scale infestation can also attract ants, which, in turn, can feed directly on your almond nuts.
- Mites. Mites attack almond trees in the same way that aphids do: preventing proper photosynthesis from taking place and causing green leaves to turn yellow and drop.
- Tent caterpillars. These hungry little critters can easily make short work of your almond trees’ leaves, stunting their growth and thereby affecting the amount of almond nuts they can produce come harvest time.
- Leafroller larvae. These are pests that can be identified by their green bodies and black heads. They can be found feeding mostly on almond tree buds, especially as they’re opening.
- Borers. Borers or boring insects are a constant threat to many fruit- and nut-bearing trees, and the almond tree is no exception. While tree-trunk boring varieties may pose no threat at all to a healthy almond tree, other varieties such as navel orangeworm, peach twig borers and oriental fruit moth larvae target almond hulls directly in order to feed on the nutmeat within.
- Rodents and birds. Thieving birds, squirrels and other rodents can prey upon your almonds even before you’ve started harvesting, which could bring down your total yield even more.
The almond tree is also susceptible to many diseases, some of which are caused by bacterial infection while others are fungal or even viral of origin. Allowing these diseases to run rampant in your orchard can not only cause a huge drop in production but also result in the death of your trees. Here are some examples:
- Ganoderma. Ganoderma is a serious fungal infection that can devour an almond tree from within, eating away at its heartwood, and causing it to just snap in half and fall over during a strong wind. It spreads through fungal spores that are released by other infected trees in the vicinity, with the biggest indicator of infection being a large conk or mushroom sprouting at the base. This conk releases the fungal spores.
- Verticillium wilt. This soil-borne fungal disease can easily kill a significant number of your almond trees if allowed to thrive in your orchard. The fungus that causes the disease enters through the root system and slowly creates blockages within, preventing the tree from getting the water and sustenance it needs to grow and produce.
- Crown gall. A bacterial disease caused by the pathogen Agrobacterium tumefaciens, crown gall firsts infects an almond tree through wounds on its bark. Once inside, it starts to create galls which can result in blocking water and nutrients from reaching the uppermost parts of the tree, thus killing off leaves and other growths.
- Botryosphaeria canker. Just like the crown gall and verticillium wilt, this fungus-borne disease stunts an almond tree’s growth by spreading canker sores throughout its cambium and heartwood tissues, preventing the smooth flow of nutrients and water from the roots to the uppermost parts of the tree itself.
Irrigation is an important part of growing any crop for the purpose of profitability, and almond trees are no different. However, when it comes to almond trees, issues with irrigation could result not just in stunted growth but also a host of other problems, such as the proliferation of diseases.
- Over-irrigation. Almond trees getting excess water can make them susceptible to fungal diseases such as hull rot, crown rot, and root rot. Too much moisture, especially in the base and the roots of trees can also speed up mold and fungal growth, which can weaken trees even further and cause potential collapses.
- Under-irrigation. Too little water, on the other hand, obviously prevents the tree from growing up healthy and productive.
This is by no means an exhaustive list, but this should give you an idea about some of the most important threats to almond orchard’s productivity. By mitigating the effects of these threats through good farming practices and by using modern technological tools, orchard operators and farmers can ensure the productivity of their almond trees.