Seeding Rate Effects on Rough Rice Yield, Head Rice, and Total Milled Rice

Abstract

Without an adequate and uniform rice (Oryza sativa L.) stand, optimum rough rice yields are difficult to attain. Most seeding rate research has emphasized optimizing rough rice yields, with little consideration given to the effect of seeding rate on head rice (percentage of whole milled kernels) and total milled rice (percentage of whole milled kernels plus milled broken kernels). Thus, our objective was to assess the effect of seeding rate on head rice and total milled rice of two very early‐season rice cultivars (Millie and Adair) and two midseason rice cultivars (Katy and Kaybonnet). The experiment was conducted at the Pine Tree Experiment Station near Colt, AR, during 1992 and 1993. The cultivar (maturity group) × seeding rate interaction was significant for head rice and total milled rice, suggesting that, for head rice and total milled rice, the four cultivars responded differently to seeding rate. There was a linear decrease in head rice as seeding rate decreased for Millie, a quadratic decrease in head rice as seeding rate decreased for Adair, and a linear increase in head rice as seeding rate decreased for both Katy and Kaybonnet. We surmise that increased tillering and decreased kernel weights at the lower seeding rates decreased the head rice for Adair and Millie. Total milled rice decreased linearly with decreasing seeding rate only for Adair. When evaluating thin rice stands for potential performance or replanting, both cultivar and head rice and total milled rice losses should be considered.

Green Bean Yield and Path Analysis in Cowpea Landraces

“…However, in other crops, direct selection can be more, less, or as effective as indirect selection (ATLIN;FREY, 1989;BRANCOURT-HULMEL et al, 2005;KUMAR;BAHL, 1992;McNEW, 1992). An alternative approach is to combine selection for grain yield with selection for number of pods per plant using selection indexes (ROSIELLE;FREY, 1975;GRAVOIS, 1998).…”

Influence of Milling Parameters on Head Rice Recovery: A Review

“…Head rice is capable of fetching two to three times more price than that of broken kernels. A number of studies have been focused on improving milling quality through plant breeding programs, improved cultural practices, optimization of harvesting and drying conditions (Abud et al, 2000;A-Bond et al, 2007;Dong et al, 2003;Gravois, 1998). Delay in harvest has been shown to reduce HRY due to low kernel moisture contents (Sajawan et al, 1990), optimum moisture content for seven US varieties to harvest varied from 16% to 21.5 % (d.b.)…”

Use of gross income as a measure of productivity in rice breeding

“…Cultural factors include seeding date (Gravois and Helms 1998), time of draining the field (McCauley and Way 2002), and harvest grain moisture (Jodari and Linscombe 1996;McCauley and Way 2002), whereas moisture adsorption of rough rice (Siebenmorgen and Jindal 1986;Siebenmorgen et al 1992), and degree of milling (Reid et al 1998) are examples of post-harvest handling factors. Cultivar parameters that affect milled rice percentages include grain length and susceptibility to grain fissuring (Jodari and Linscombe 1996), panicle density, filled grain per panicle, and grain weight .…”

“…Although some have reported the importance of developing cultivars having high and stable rough rice and whole milled rice yields as a means of maximizing the economic value of a rice crop (Gravois and Helms 1998;McCauley and Way 2002), there have been no studies on the GE interaction analysis of gross income. The objectives of this study were to determine the usefulness of genotype plus genotype )environment (GGE) biplot analysis to identify genotypes that produced high and stable expected gross incomes.…”