WEEK II
May 19
Ecological Integrated Pest Management
According to Masanobu Fukuoka, Japanese farmer and philosopher who wrote, among other books "The One Straw Revolution", in a healthy and diverse farm ecosystem, the crops grow vigorously and live natural lives, but that doesn't mean they are pest or insect free. The damage they cause must be allocated to provide food for the birds and insects and to thin out the weakest individuals (Masanobu Fukuoka, Sowing Seeds in the Desert).
Over the last decades, mankind has been obsessed with the idea of being able to "control" agricultural pest. The approach has been to treat pests as "enemies" who compete with humans for resources, and not as important components of the farm ecosystem. The problem with this linear approach is that by removing a pest from the ecosystem we are trying to manage, either by spraying a pesticide or an herbicide, we are creating the niche for another pest species to move in. We also encouraging the development of "resistance to pesticides" in the pest population. A more ecological approach has been to incorporate the idea that pests populations cannot be controlled but "managed". Ecological Integrated Pest Management (EIPM) approach takes into consideration the complexities of pest population dynamics, the various causes of pest outbreaks, and the factors determining the abundance and distribution of pests, and tries to combine a number of biological control applications to keep pest populations at a level that it would not have a significant effect in crop production and yield.
Farm Management Practices
Richmond Terraces Field Notes
Late Blight in Potato Plants
We started observing Late Blight symptoms in the leaves of potato plants growing in the west terrace (Fig. 1 to 3). The use of sprinkler irrigation might be contributing to the occurrence of this oomycete, which is extremely common in our area, by creating a moist environment where the organism could thrive. At this point, it is too late to try to apply any organic pesticide, most of the pesticides available in the market serve as a preventive measure and must be applied before planting the potatoes/tomatoes. There's a non-organic alternative that is widely used among potato growers,that involves spraying with a coper containing solution, but we overruled the option, since we are trying to keep the patch as organic as possible.
Fig 1. Potato Leves displaying yellow lesion
Fig 2. Young Potato Leves displaying yellow lesion
Fig 3. Potato leaves displaying yellow and brown lesion
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Lady Bugs: a biological control approach to manage mite populations in broad beans
The broad beans on the west terraces developed a significant mite problem. Broad bean mites have a short generation time (5 days) and high fecundity, as a consequence, populations occur in a large numbers. The plant injury they produce is often confused with deceases and phytotoxicity, however studies show that some of the symptoms following mite attack are due to various diseases including plant viruses. In any case, broad mites reduce, market yield and injure plants by damaging their leaves, flowers and fruits. Plants under heavy attack stop growing and die. (Peña, J. E., & Bullock, R. C. (1994). Effects of feeding of broad mite (acari: Tarsonemidae) on vegetative plant growth. The Florida Entomologist, 77(1), 180-184.)
Fortunately, a healthy ladybug population could also be observed applying some sort of biological pressure over the mite population (Fig 4 to 7). We decided to monitor the plants and observe their progress before selecting a more invasive pest management approach.
Fig. 4 Ladybug in broad bean plant
Fig. 5 Ladybug pupae in broad bean plant
Fig. 6 Ladybug cluster of eggs in broad bean plant
Fig. 7 Unknown brown cluster in broad bean leaf
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Sun Scald in Indoor Seedlings
Seedlings that are growing indoors are very susceptible to developing white leaves when they are moved outside for the first time.
Treatment: Move seedlings back into a part shade environment.Remove badly bleached leaves. Reintroduce to full sun in a couple days.
Fig. 8 White tips of sun scald in pepper seedlings
Fig. 9 White tips of sun scald in tomato seedlings
Building our Tunnel and Transplanting the Seedlings
We were successful in building our tunnel. It only needs a few adjustments.
Having the tunnel in place we were able to transplant the Tomatoes, Peepers, Squash, Zucchini, and Cucumber Seedlings we grew in the Lab during the Sring Semester. Some of the Tomatoes Peppers and Zucchinis were placed in the tunnel.
