|00-828 Project Manager: P. F. O'Leary|
IMPACT OF CROP PRODUCTION PRACTICES ON PEST POPULATIONS IN NEW MEXICO
Jane B. Pierce and Patricia E. Monk, New Mexico State University
Cotton glands produce gossypol, a natural defense against insect pests. Glandless cotton varieties have been developed but were rejected as a commercial crop in many areas due to losses from pests. New Mexico has lower insect pressure than most of the cotton belt, and could potentially produce glandless varieties as a niche crop with added seed value. In 2012, field trials were conducted on a New Mexico State University farm to evaluate the influence of nitrogen and glandless cotton on cotton bollworm and beet armyworm survival and development in field and lab trials.
Field petiole nitrate levels were 1573-1765 ppm N in low nitrogen treatment plots and 5211-6243 ppm N in high nitrogen treatment plots when a field to lab bioassay was initiated. Survival was not affected by nitrogen levels in the first 48 hours in early instar larvae. Survival to pupation also was not affected by nitrogen level. Beet armyworm fourth instar larvae were 30% larger and required two less days to reach pupation on high N cotton. Bollworm pupal weights were 9% larger on high N cotton but there was no significant difference in fourth instar larval weights or days to pupation
Effects of glandless cotton were more notable. Although there was no difference up to 48 hours, bollworm and beet armyworm survival was 5-10 times higher at pupation on glandless cotton. Beet armyworm fourth instar larval weights and pupal weights were not different on glandless or glanded cotton. However, those on glandless leaves required 4 less days to reach pupation. Bollworm fourth instar larvae were 69% heavier, pupae were 16% heavier on glandless cotton squares, and pupated in 9 fewer days compared to those on glanded cotton. Bollworm larvae also developed 43% faster on glandless cotton pupating in 21 days vs. 30 on glanded cotton.
Field square damage was significantly higher in glandless plots compared to glanded plots. Glandless plots had twice as many damaged squares with 6% damaged squares compared to 3% damaged squares in glanded plots. The number of damaged squares were not affected by N levels.
|Project Year: 2012|
Search 2012 Projects:|
▸ New Mexico
▸ North Carolina
▸ South Carolina
▸ Cotton Incorporated Fellow
▸ Crop Improvement
▸ Production Efficiency
▸ Sustainable Cotton
▸ Variety Improvement
▸ All Project Nos.