Effect of volunteer rice infestation on grain quality and yield of rice

Authors: SINGH, VIJAY - University Of Arkansas; BURGOS, NILDA - University Of Arkansas; SINGH, SHILPA - University Of Arkansas; Gealy, David; BRYANT, ROLFE - Retired ARS Employee; GBUR, EDWARD - University Of Arkansas; CAICEDO, ANA - University Of Massachusetts

Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/17/2016
Publication Date: 6/17/2016
Citation: Singh, V., Burgos, N.R., Singh, S., Gealy, D.R., Bryant, R.J., Gbur, E.E., Caicedo, A.L. 2016. Effect of volunteer rice infestation on grain quality and yield of rice. Pest Management Science. doi:10.1002/ps.4343.

Interpretive Summary: Rice plants that develop in rice fields from seeds that were shattered from the heads of plants from the previous rice crop (referred to as “volunteers”) can potentially reduce the yield and the commercial value of the grain from current rice crop. This can occur because volunteer plants from a rice variety other than the one planted for the current crop can produce grains that have physical and chemical properties which are quite different from the planted variety, and thus may reduce the uniformity and quality of harvested rice grain. To better understand the potential effects of volunteer rice infestations on rice yield and grain quality in commercial rice production fields, numerous rice fields were surveyed in Arkansas in the fall of 2012. Rice heads were collected from several different sites that represented a range of different infestation levels within each field. Our analysis showed that infestation levels of volunteer rice in fields with a history of growing hybrid rice varieties over the previous two years were more than three times those present in fields planted previously with traditional inbred rice (20% vs. 5.6%). Overall, the total grain yield of rice was reduced by about 4% for every 10% increase in the infestation level of the volunteer rice. Furthermore, the rice kernel weight, dimensions, and chemical and milling quality were also adversely affected by volunteer rice infestations when different varieties were grown in the previous two years. These studies demonstrated in a practical way that volunteer rice from different varietal groups have the potential to negatively impact the yield, grain quality, and commercial acceptability of rice, and highlight the need to manage volunteer rice plants aggressively and effectively.

Technical Abstract: Volunteer rice (Oryza sativa L.) plants arise from shattered seeds of the previous crop, which could reduce the yield of cultivated rice and the commercial value of harvested grain. Volunteer rice plants from a cultivar other than the current crop produce grains that may differ in physico-chemical traits from the planted cultivar, which can reduce the uniformity and milling quality of harvested rice grain. To evaluate the effect of volunteer rice infestations on rice yield and grain quality, 20 commercial fields were surveyed, across six rice growing counties of Arkansas in the fall of 2012. Panicles were collected from 1-m2 areas (4-8 sites per field) representing different levels of infestations across the field. Cropping history that included hybrid cultivars over the previous two years (2010 and 2011) led to higher volunteer rice infestation (20%) in 2012 compared with fields planted previously with inbred rice (5.6%). The total grain yield of rice was reduced by 0.4% for every 1% increase in volunteer rice density across all fields, averaged over cultivars. The 1000-kernel weight, kernel length-width ratio, %protein, %amylose, and head rice yield (HRY) were affected by volunteer rice infestation and cultivars grown in the previous two years. The protein content, amylose content, chalk, and physical dimensions of harvested grain were not affected when the same cultivar was planted three consecutive years. These results demonstrate that volunteer rice can negatively impact rice yield and grain quality, and thus, should be managed effectively.