Effects of photoperiod on reproductive development of peanut (Arachis hypogaea L.) in a cool subtropical environment. II. Temperature interactions

1991 ◽  
Vol 42 (7) ◽  
pp. 1151 ◽  
Author(s):  
MJ Bell ◽  
DJ Bagnall ◽  
G Harch

The effects of temperature on the response to photoperiod by peanut (Arachis hypogaea L.) cultivars were examined under glasshouse and phytotron conditions at two locations (Kingaroy and Canberra). Two Virginia cultivars (Early Bunch and Robut 33-l), two Spanish cultivars (White Spanish and TMV-2) and a single Valencia (NC 17090) cultivar were grown in the experiments. White Spanish was common to both studies. Strong photoperiodxtemperature interactions were shown for all cultivars in both experiments, with the sensitivity of peg number to photoperiod increasing at higher temperatures. Photoperiod responses were all indicative of short-day (SD) response types, and were always expressed in post-flowering reproductive development. No effects of photoperiod on time to first flower were evident, but numbers of pegs and pods and total pod weight per plant were reduced in long (16 or 17 h) photoperiods. Data from field experiments at Kingaroy were pooled with those from the glasshouse and controlled environment studies to estimate the critical temperatures above which photoperiod sensitivity became significant. Hourly temperature readings were used to calculate a daily heat sum (�C h) above a base temperature of 10�C for each experiment. This index of the temperature condition proved satisfactory as a possible discriminatory method to describe environments based on likely photoperiod response. Environments where daily heat unit accumulations greater than 340-350�C h were recorded during the treatment period showed significant photoperiod responses. The possibility of minimum temperature being the predominant component of the temperaturexphotoperiod interaction is also discussed. This proved less effective in discriminating between environments for photoperiod response, but data were insufficient to discount this possibility and further studies are needed. Results question the relevance of photoperiod as a factor limiting reproductive development of peanuts in cooler, subtropical environments.

1995 ◽  
Vol 22 (2) ◽  
pp. 114-120 ◽  
Author(s):  
J. V. Altom ◽  
R. B. Westerman ◽  
D. S. Murray

Abstract Field experiments were conducted from 1991 to 1993 to evaluate eclipta, Eclipta prostrata L., control and peanut, Arachis hypogaea L., response to herbicide treatments. Fomesafen {5-[2-chloro-4-(trifluoro-methyl)phenoxy]-N-(methylsulfonyl)-2-nitrobenzamide} applied at cracking was the only preemergence-applied herbicide which provided season-long control (>84%). Herbicides applied postemergence were more effective when the eclipta was less than 5 cm in height. The most consistent early postemergence treatments were bromoxynil (3,5-dibromo-4-hydroxybenzonitrile), bentazon [3-(1-methylethyl)-(1H)-2,1,3-benzothiadiazm-4(3H)-one 2,2-dioxide], and bentazon + acifluorfen {5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid} + 2,4-DB [4-(2,4-dichloro-phenoxy)butanoic acid]. Various other early postemergence followed by late postemergence sequential treatments also were equally effective. Minor peanut injury was observed at the early season rating from several herbicides; however, all injury had disappeared by the late season rating. Eclipta control did not consistently improve peanut pod yield.


2012 ◽  
Vol 39 (1) ◽  
pp. 9-14 ◽  
Author(s):  
P. A. Dotray ◽  
W. J. Grichar ◽  
T. A. Baughman ◽  
E. P. Prostko ◽  
T. L. Grey ◽  
...  

Abstract Field experiments were conducted at nine locations in Texas and Georgia in 2005 and 2006 to evaluate peanut tolerance to lactofen. Lactofen at 220 g ai/ha plus crop oil concentrate was applied to peanut at 6 leaf (lf), 6 lf followed by (fb) 15 days after the initial treatment (DAIT), 15 DAIT alone, 6 lf fb 30 DAIT, 30 DAIT alone, 6 lf fb 45 DAIT, 45 DAIT alone, 6 lf fb 60 DAIT, and 60 DAIT alone in weed-free plots. Lactofen caused visible leaf bronzing at all locations. Yield loss was observed when applications were made 45 DAIT, a timing that would correspond to plants in the R5 (beginning seed) to R6 (full seed) stage of growth. At all locations except the Texas High Plains, this application timing was within the 90 d preharvest interval. Growers who apply lactofen early in the peanut growing season to small weeds should have confidence that yields will not be negatively impacted despite dramatic above-ground injury symptoms; however, applications made later in the season, during seed fill, may adversely affect yield.


1981 ◽  
Vol 8 (1) ◽  
pp. 66-73 ◽  
Author(s):  
G. A. Buchanan ◽  
E. W. Hauser ◽  
R. M. Patterson

Abstract Experiments were conducted from 1975 to 1977 to determine the efficacy of herbicides for control of bur gherkin (Cucumis anguria L.) in peanuts (Arachis hypogaea L.). Most bur gherkins seed planted in the field germinated in the upper 2.5 cm of soil, although some seed germinated from 7 cm. In greenhouse and field experiments, preplant-incorporated applications of vernolate (S-propyl dipropylthiocarbamate) substantially reduced the green weight of bur gherkin plants and also improved the efficacy of several cracking and postemergence herbicidal treatments. Postemergence treatment sequences were much more effective when they were begun while bur gherkins were in the cotyledonary stage of development rather than the 3- to 5-leaf stage. Preplanting application and incorporation of vernolate + benefin (N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine), followed by a cracking application of alachlor [2-chloro-2',6'-diethyl-N-(methoxymethyl)acetanilide] + naptalam (N-1-naphthylphthalamic acid) + dinoseb (2-sec-butyl-4,6-dinitrophenol), followed by dinoseb controlled bur gherkins. Some of the most intensive herbicide programs reduced the yield of peanuts in some experiments. Bur gherkin plants that survived the herbicide treatments produced substantial quantities of fruit and seed.


1991 ◽  
Vol 42 (7) ◽  
pp. 1133 ◽  
Author(s):  
MJ Bell ◽  
G Harch

The effects of photoperiod on reproductive development and yield of two Virginia, one Spanish and one Valencia peanut (Arachis hypogaea L.) cultivar were investigated in the field at Kingaroy, Australia. The objective was to assess the importance of photoperiod as a limitation to post-flowering reproductive development in a cool subtropical environment. A total of five experimental sowings were made between the 1986/87 and 1988/89 growing seasons. Treatments consisted of either natural photoperiods (ranging from 11 to 14 h, depending on sowing date and growth stage) or long (16 h) photoperiods during a range of phenological stages, both pre- and post-flowering. Long photoperiods were achieved by using low intensity light from incandescent bulbs with equal extension periods in both morning and evening. Different sowing dates and seasons were used to produce a range of natural photoperiods, radiation and temperature regimes, while shadecloth was used to alter incident irradiance during the 1988/89 experiments. Photoperiod responses were significant in only one experiment (S2, 1986/87), and were due to effects of treatment during the immediate post-flowering period. Numbers of flowers, pegs and pods were reduced under long photoperiods in cv. Robut 33-1, and to a lesser extent, in cv. White Spanish. The Virginia cv. Uf 781 14-5 was unaffected. The effects of long photoperiods during this 30 day post-flowering treatment were not expressed until after the treatment period. Effects were relatively small and reproductive (pod) yields at maturity were not significantly reduced. The lack of strong photoperiod responses in the reportedly sensitive Valencia cv. NC17090 and the occurrence of the strongest response in the relatively insensitive cv. Robut 33-1 were unexpected. Analysis of climatic data from these experiments, and others reported in the literature, suggested interactions between photoperiod and temperature, with photoperiod effects being only significant at higher temperatures, i.e. in our studies, when mean daily temperature during the treatment period was 26-0�C. This finding is of considerable significance in assessing the importance of photoperiod sensitivity for cultivar adaptation to long day/subtropical environments. A subsequent paper in this series examines photoperiod x temperature interactions more closely under controlled environment conditions.


2000 ◽  
Vol 27 (1) ◽  
pp. 11-16 ◽  
Author(s):  
G. Wehtje ◽  
B. J. Brecke ◽  
N. R. Martin

Abstract Field experiments were conducted over two growing seasons (1995 and 1996) and at two locations (Jay, FL, and Headland, AL) to identify the most effective herbicide program for Florida beggarweed [Desmodium tortuosum (SW) D.C.] control in peanut (Arachis hypogaea L.). The most common herbicides used for Florida beggarweed control—including preemergence (PRE), early-postemergence (EPOST), mid-postemergence (MPOST) and late-postemergence (LPOST) applied treatments—were evaluated in a factorial treatment arrangement. All treatments had merit and could be assembled into programs that resulted in maximum weed control, crop yield, and net returns. However, at least two of the four treatment timings were required to reach this level. Four systems were consistently associated with the maximum statistical grouping for both yield and net returns, as well as acceptable Florida beggarweed control (> 81%). These systems were (a) paraquat + bentazon applied EPOST, followed by pyridate + 2,4-DB MPOST; (b) same as (a) only preceded by norflurazon applied PRE; (c) imazapic applied EPOST followed by pyridate + 2,4-DB MPOST; and (d) norflurazon applied PRE, followed by imazapic EPOST.


1996 ◽  
Vol 23 (1) ◽  
pp. 30-36 ◽  
Author(s):  
W. James Grichar ◽  
A. Edwin Colburn

Abstract Field experiments were conducted in 1991 and 1993 to evaluate flumioxazin alone and in various herbicide programs for weed control in peanut. Flumioxazin alone provided inconsistent control of annual grasses, while the addition of pendimethalin or trifluralin improved control considerably. Pitted morningglory (Ipomoea lacunosa L.) and ivyleaf morningglory [Ipomoea hederacea (L.) Jacq.] control was > 75% when flumioxazin was used alone. Flumioxazin caused early season peanut stunting with some recovery within 4 to 6 wk. Postemergence applications of imazethapyr or lactofen increased peanut stunting.


1984 ◽  
Vol 11 (2) ◽  
pp. 60-63 ◽  
Author(s):  
M. E. Walker ◽  
W. D. Branch ◽  
T. P. Gaines ◽  
B. G. Mullinix

Abstract Field experiments were conducted on Lakeland sand (Thermic, coated Typic Quartz-ipsaments) during 1981-82 to determine the effect of foliarly applied N on yield, grade, and N, P, K, Ca, and Mg concentration of leaves and seed of nodulating and non-nodulating peanut (Arachis hypogaea L.). Nodulating cultivars; Florunner, Early Bunch, and Tifrun, and three non-nodulating experimental lines were sprayed 0, 1, 2 or 4 times at 13.5 kg N/ha beginning 28 days after emergence. Foliar application of N increased the yield of Florunner, Tifrun, and all non-nodulating lines, but had no effect on Early Bunch. The addition of N to non-nodulating peanut increased the percent fancy pods, extra large kernels, and weight of seed. Seed N concentration of non-nodulating lines increased with higher rates of N, but was higher in the nodulating cultivars. Seed of non-nodulating lines contained higher levels of P, K, and Mg than seed of nodulating lines. Nodulating lines had higher concentration of leaf N than did non-nodulating lines. The leaves of the non-nodulating lines contained higher levels of P, Ca, and Mg than those of the nodulating cultivars; whereas levels of K were higher for nodulating lines.


1996 ◽  
Vol 23 (1) ◽  
pp. 54-57 ◽  
Author(s):  
Alan C. York ◽  
Roger B. Batts ◽  
A. Stanley Culpepper

Abstract Field experiments in North Carolina in 1994 and 1995 determined virginia-type peanut (Arachis hypogaea L.) response to PGR-IV, a commercial hormonal growth regulator consisting of 30 mg/L of gibberellic acid, 27 mg/L of indolebutyric acid, and a proprietary fermentation broth. Treatments included PGR-IV applied once at 438 mL/ha 21, 45, 60, or 75 DAE (days after peanut emergence) or twice at 219 mL/ha at 21 and 45 DAE or 45 and 60 DAE. PGR-IV had no effect on peanut main stem or cotyledonary lateral branch length, yield, maturity, percentage of fancy pods, extra large kernels, or total sound mature kernels, or net returns.


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