Harvest Time

By June 17, 2007Archives, Opinion

Integrated weed management solves recurring low income

By Sosimo Ma. Pablico

The recurring low income of farmers practicing direct seeding of rice in Dingle, Iloilo has been solved through integrated weed management.

In the past, Dingle rice farmers had difficulty controlling the weeds despite the use of herbicides.  Until lately, they noticed that the weeds were getting more and more difficult to control despite increasing dosage and frequency of application.  Some of the weeds could not even be killed anymore.  As a result, their cost of production was getting bigger like a balloon and their net income was commensurately decreasing.

Three farmer leaders – Butsoy Guanga Jr., Nits Dagohoy, and Nanay Lydia Gomito –  narrated that it was in a farmers’ field school conducted jointly by PhilRice, Department of Agriculture – Region 6 and the municipal agriculture office that they learned slowly but surely need not be applied whenever weeds are seen in the field.  Thirty farmers participated in the FFS.

They learned that preventing weeds from growing is cheaper and easier than removing them.  This can be done by preparing the land thoroughly and properly at least a month before planting.

Repeated harrowing or herbicide application one to three weeks before planting would kill the weeds that have already emerged.  Certified seeds must also be used to ensure that there are no seeds mixed in the rice seeds.

This is followed by an application of pre-emergence or early post-emergence herbicide at 1 to 4 days after seeding [DAS] to ensure that weed seeds will no longer germinate.  Then flood the field at 7 to 10 DAS and maintain water depth at 5 to 7 centimeters [cm] until the grains mature.

For transplanted rice, however, pre-emergence herbicide may be applied at 3 to 5 days after final leveling of the field.  Where the golden apple snail is not a problem, flood the field 3 to 4 days after transplanting and maintain water depth of 2 to 3 cm to prevent emergence of weeds.

The farmers observed that integrated weed management is more effective than their previous practices.  They learned that if some weeds still grow, they may just as well remove the weeds manually if the weeds occupy only less than 5 percent of the field.  At this level of weed infestation, fields may not be weeded anymore, as the weeds will no longer affect their yields.

They also learned that indiscriminate use of insecticides (almost every week) kills the friendly insects that help keep the population of harmful insects at a tolerable level.  Friendly insects feed on harmful insects and, thus, help keep down their population.

Having learned to distinguish friendly insects from the harmful ones, they now try to maintain the population of the friendly insects.  Thus, they monitor the insect population as their basis of deciding when to spray their crops with insecticides. They collect insects and then count the friendly and harmful ones.  A ratio of five harmful insects or less to one friendly insect tells them not to bother about spraying insecticide, as this level will not affect the yield. 

They lament, however, that many Filipino farmers still do not know about the existence of friendly insects and their importance.

The farmers now also use only 40 kg of certified seeds and decompose their rice straw to save on cost.  In the past, they were direct seeding per hectare 160 to 200 kg of seeds taken from their previous harvest. 

Moreover, they have realized that the rice straw is a valuable resource and, hence, they now decompose it to become of nutrients and organic matter.  Before land preparation, they spread the decomposed material in the field to be incorporated in the soil during the first plowing.

Eventually, the municipal council upon the recommendation of the municipal agriculture office passed an ordinance prohibiting the burning of rice straw. 

As a result, their yields have increased and with greatly reduced production cost, their net income has improved a lot.

(For past columns, click http://sundaypunch.prepys.com/archives/category/opinion/harvest-time/)

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