![]() ![]() Managed by good agronomic practices, fungicide seed treatments, and variety resistance.Foliar insects: - Plant early! - crop monitoring - insecticide only when needed, rare - Bt transgenics (corn borers, ear- worms, armyworms.(Photo courtesy of Jeff Whitworth, K-State Department of Entomology) Download this photo Armyworms taking aim at farmer’s fields K-State crop entomologist discusses worms in agricultural fields Sept. Soil insects: - field history - insecticides: - in-furrow - over the top Corn rootworm wireworm K-State Research and Extension News Armyworms are being reported in higher numbers this fall in Kansas farm fields.Apply ½ pre-plant, the other ½ sidedress at V5-7 Pre-plant N, P, K Side dressing liquid N fertilizer.Try to get uniform stand and emergence.Why?) - reduce late-season insect pressure - catch early rains - avoid late summer heat - higher yields, less input costs 1 - look at experiment station yield trials - Transgenic traits, ie., ‘RR’, ‘Bt’ - Maturity, ie., early, mid-late - Cost, availability of seed - Disease resistance New developments are herbicide resistant (glyphosate and some others) and internal insecticide producing transgenic varieties.Hybrid seed corn development: - develop stable ‘inbred’ lines - cross two different inbred lines - plant the seed produced (F1 hybrid) - offspring will yield 2-5X parents!.1940’s: Hybrid corn seed production revolutionized corn production, 2-3 fold yield increases seen in some areas!.Dent types emerged about 1500 years ago.Considerable variability due to open pollination. ![]() No known close relative, best match is a perennial grass called ‘teosinte’.Spread to SW, SE, NE and then to great plains and Canada.Early signs of cultivation about 8000 years ago.Reproduction: tasseling silking anthesis (pollen shed) ‘milk’ – ‘soft dough’ – ‘dough’ – early dent – late dent Black Dot (physiological maturity).internode elongation (IE) or ‘jointing.Transgenic types: - herbicide, ie., RR - insecticide, ie., ‘Yieldguard’ (Bt) - others coming!.Five main kernel types: - flint: popcorn, ornamental - flour - waxy - sweet (white, yellow, mixed) - dent.Panicle, florets with sterile ovaries Ear, only has floret pistol: stigma, style (silk), and fertile ovary (kernel). ![]()
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