Survey and Identification of Common Weeds Associated with Rice and Vegetable Production in Rosario, La Union, Philippines

Angelina T Gonzales

doi:10.13189/ujps.2017.050301

Abstract

A preliminary survey, collection and identification of weeds in rice and vegetable production areas in Rosario, La Union, Philippines were done to identify most common and prevalent weeds associated with rice and vegetable. Fields surveys were done according to the quantitative survey method using 1.0m x 1.0m size quadrat with 20 samples from each field. Weeds present in each field were identified and the data were used to calculate frequency and relative dominance values for each species. A total of 45 species of weeds were collected and identified. Dominant weeds in vegetable and rice production during wet season were Digitaria sp., F. littoralis, A. conyzoides, C. pubescens and D. aegyptum. However, dominant weeds in rice production area were: Digitaria sp. and Dactyloctenium aegyptium; while Chloris sp. and Fimbristylis littoralis Gaudich, Centrosema pubescens Benth and Cyperus killingia and Cyperus rotundus L. and Dactyloctenium aegyptium at vegetable area. Based on the survey annuals were more dominant than perennial. More survey work is needed on a regular basis to identify possible problematic weed and weed population shifts and direct research toward new or improved control measures.

Highlights

The annual global economic loss caused by weeds has been estimated at more than $100 billion U.S dollars [2]
Results of the survey on common weed species associated with rice and vegetable production areas during wet season yielded a total of 45 weed species in the surveyed areas
Dominant weeds associated with vegetable and rice plantation areas in Nagtagaan Campus, Rosario, La Union belong to grasses group and they were: Dactyloctenium aegyptium (L) Beauv., Digitaria sp., Eleusine indica (L) Gaertn., Trianthema portulacastrum L., Cyperus rotundus L. and Amaranthus spinosus L. for the wet season (Table 1)

Summary

Introduction

The annual global economic loss caused by weeds has been estimated at more than $100 billion U.S dollars [2]. Weeds, considered as obnoxious plants, are one of the pests associated with any agriculture endeavor and compete with rice and vegetable plants for sunlight, space, water, and nutrients in the soil. Weeds may act as alternate hosts to insect pests and pathogens attacking vegetable and rice production areas. 10% of agricultural production is lost as a result of crop weed competition for the resources light, water and nutrients [14]. The author reported loss estimates of 5% in developed countries, 10% in the less developed countries and 25% in the least developed countries. This clearly indicates problems associated with weed control in tropical crops. When weeds are left uncontrolled, yield losses range from 20-100% depending upon the crop and its environment

Methods

Results

Conclusion