9. IRRI Agronomy Challenge: Golden Apple Snail and Counting Plants (19 & 26 January 2012)
Channel: International Rice Research Institute
Date: 30/01/2012

The golden apple snail is a menace to young rice seedlings because it cuts and kills the seedlings as it grows. It is common in wetland areas such as rice fields and swamps.

Achim and Leigh are worrying a lot about this snail because it moves fast through the field if there is standing water. Their field has plenty of these snails, either dug into the soil or in places where there is some standing water. They step on them all the time when walking through the field, which is not exactly pleasant. 

They were not keen to apply a very toxic chemical to control the snails. Instead, they opted for irrigating more frequently during the week following the first irrigation, trying to keep most of the field under shallow flooding, but also hoping to not make it too easy for the snails to move around.

See http://www.knowledgebank.irri.org/factsheets/index.php/pest-management/golden-apple-snail

Counting plants (26 January):
Commentary by Mr. Vial: "We did plant counts today, and just in time as tillering has started. I fabricated a 0.1-square meter ring, which I threw randomly around as I walked through the field. We averaged 12.8 plants inside our ring, or 128 plants per square meter. 

The count ranged from 1 plant to 32 plants and 6 of the 23 counts were less than 10...perfectionists will hate this! This is a touch less than the average of 150 plants we aimed for, but given the low weed burden, I have few concerns. I have seen many excellent yields from well less than 100 plants per square meter. 

We have transplanted about a 1-meter strip down the side where our birds ate so well, and manually removed some perennial grass encroaching from the bunds. Shall we call it precision management? The field is being irrigated twice a week for now to keep close to water coverage...we will wait for something like canopy closure (another 2-3 weeks?) before changing to AWD to preserve some water.